I'm no electrical guru, but there are a few regulars of this forum who are. They should be along to help. Have you checked for blown fuses? BTW there was no 2001, it came out a year later. I advocate changing all fuses to the EZ-ID or SmartGlo kind makes finding problems so much easier as they light up when they blow. Check the 30 amp fuses behind the left side case, behind the frame downtube. Only 2 are used, the 3rd is a spare. Do you have a multi-meter to check things? Hans & Feet is really good with trouble-shooting esp. electrical. Hope he sees this, or you could send him a 'private conversation'. Good luck.
What have I done? Running perfectly now won't start at all.
Can any of you guys help, please.
I picked up a 2001 C model a couple of years ago. It has run perfectly for months and months of riding. Recently I was aware of a change in the engine sound, light rattling so I learnt how to do the valve adjustments and did it, all to spec, even getting the hang the tricky exhaust valve of the rear cylinder. I put everything back together but on startup and during idle there were occasional but regular backfires. I checked the plugs (which have about 1000 miles use) and saw the front cylinder left side spark plug was wet so I followed the post recommendations to check again all grounding on every possible surface of the coils, I cleaned, sanded, added dielectric grease BUT I now know that I made an big mistake with the front coil and put the black and white coil wire on the wrong connector, even so the bike started up and ran perfectly. That was a couple of weeks ago. I didn't go riding but started the bike every day. Today there were backfires again and the front cylinder stopped firing, then both cylinders died completely. Looking at the posts I followed the advice to clip the coil ends of the HT leads. They looked in better shape then, and I added dielectric grease. It was at this point I realised that I had previously put the black and white coil wire on the wrong connector of the front coil so this time I connected it as it should be. I expected it to start and run smoothly but it didn't start at all.
My first reaction was that I had caused an electrical fault by my error with the front coil wires. I lifted the tank and checked the electrical connection (the one you need to disconnect when removing the tank). To be sure I disconnected and pushed it together again. The fuel pipe was connected correctly and not trapped or kinked, the breather was as it should be, and the other tube (is this the one returning from the injection?) was fastened firmly over the brass fitting of the fuel pump assembly (which is part of the tank on this 2001 model). I pressed the starter button, it turned the engine healthily but it did not start.
I was working on the bike all afternoon and into the evening retracing my steps.
There is fuel in the tank (not much, because I wanted to remove the tank, but there is new fuel splashing about in there).
I hear the fuel pump prime the system when I turn on.
The starter turns the engine but no start.
It got too dark, but I did check the front right side plug to see if there was life, and that one has spark.
The battery is good and charged.
I will be out there again tomorrow. So any tips would a great help.
I picked up a 2001 C model a couple of years ago. It has run perfectly for months and months of riding. Recently I was aware of a change in the engine sound, light rattling so I learnt how to do the valve adjustments and did it, all to spec, even getting the hang the tricky exhaust valve of the rear cylinder. I put everything back together but on startup and during idle there were occasional but regular backfires. I checked the plugs (which have about 1000 miles use) and saw the front cylinder left side spark plug was wet so I followed the post recommendations to check again all grounding on every possible surface of the coils, I cleaned, sanded, added dielectric grease BUT I now know that I made an big mistake with the front coil and put the black and white coil wire on the wrong connector, even so the bike started up and ran perfectly. That was a couple of weeks ago. I didn't go riding but started the bike every day. Today there were backfires again and the front cylinder stopped firing, then both cylinders died completely. Looking at the posts I followed the advice to clip the coil ends of the HT leads. They looked in better shape then, and I added dielectric grease. It was at this point I realised that I had previously put the black and white coil wire on the wrong connector of the front coil so this time I connected it as it should be. I expected it to start and run smoothly but it didn't start at all.
My first reaction was that I had caused an electrical fault by my error with the front coil wires. I lifted the tank and checked the electrical connection (the one you need to disconnect when removing the tank). To be sure I disconnected and pushed it together again. The fuel pipe was connected correctly and not trapped or kinked, the breather was as it should be, and the other tube (is this the one returning from the injection?) was fastened firmly over the brass fitting of the fuel pump assembly (which is part of the tank on this 2001 model). I pressed the starter button, it turned the engine healthily but it did not start.
I was working on the bike all afternoon and into the evening retracing my steps.
There is fuel in the tank (not much, because I wanted to remove the tank, but there is new fuel splashing about in there).
I hear the fuel pump prime the system when I turn on.
The starter turns the engine but no start.
It got too dark, but I did check the front right side plug to see if there was life, and that one has spark.
The battery is good and charged.
I will be out there again tomorrow. So any tips would a great help.
1 - 20 of 24 Posts
Thanks for that Rangers4u, the first job then is to check the fuses. Let's see what happens with when the sun comes up on a new day. Thanks for the info about the those LED-type fuses, I've seen them so I'll order some, and thanks for the info about 2002 (there is so much I don't know and so little time to find out everything). Are you there Hans and Feet?
Wet spark plugs--fuel pressure could be leaking fuel in to intake manifold via vacuum port. The 2002 has had issues with a 2 pin connector near the starter relay, it goes between the main 30 amp fuses and +12 v battery post. tech.bareasschoppers dot com
www.vtxoa.com
"Melted wiring". In the How-to Step by Step 1800 section are several threads with pix.
The Ignition coils draws about 6 to 7 amps, may cause low voltage on the Red/White wire in the 2 pin connector.
The Ignition coil low voltage connections really don't care. One high voltage coil with one spark plug on each end of the high voltage wiring. The spark plug shell connects the sparkplugs together. Like having two bulbs in series...
Do you have a fuel manager aka power commander or something similar?
1800 diagrams for Charging, Starting and FI system
General info on 1800. 1800C uses incandescent bulbs as indicators. 1800 C/F had an extra 20 amp fuse added in 2005 (2005+) 02-04 C has dual filament front Run/Turn Signal bulbs = 1st Gen with 22 pin ECM connectors, 3 terminal TS flasher. 02-03 R/S has dual filament front Run/Turn Signal bulbs =...
www.vtxoa.com
The Ignition coils draws about 6 to 7 amps, may cause low voltage on the Red/White wire in the 2 pin connector.
The Ignition coil low voltage connections really don't care. One high voltage coil with one spark plug on each end of the high voltage wiring. The spark plug shell connects the sparkplugs together. Like having two bulbs in series...
Do you have a fuel manager aka power commander or something similar?
Thanks for your advice Hans&Feet. I'm across the Atlantic so there will be a delay posting.
By the way, the bike has no fuel manager. The only mods are the after market pipes.
I've just been out to the bike.
I checked the fuses. All good (visual inspection only, I'll redo that with multi-meter).
On the left side bike a three slot fuse box with 30 amp fuses in two slots. The third (the right of the three) is empty. For some reason this fuse box points out towards the rear wheel and all three covers were open. When I go out again I will make sure everything is clean and close the covers/lids.
I checked the two-pin connector all all looks in good condition (I'll double check with multi-meter for breaks, but definitely no sign of heat/melting).
On the right side of the bike I checked all the fuses (10 and 20 amps) and all look in good shape (I'll use the multimeter later).
I pulled the plugs. All wet.
With the pulled plugs connected and touching the cylinders I pressed the starter button. Sparks from two plugs only. I swapped them round to different HT leads on other cylinders and consistently only those same two plugs fired, the other two had no spark wherever they were put. I hadn't thought of failed plugs because they only have 1000 miles on them.
BUT while I was testing the plugs for sparks there was another symptom, something new. I pressed the starter to test for sparks then suddenly NOTHING. No power to the starter, no sound of the fuel pump priming, nothing. The battery is good and tested and charged only last week with good firm connections and a coating of dialectic grease, and the nearby ground point down to bare metal. I turned the key in the ignition switch to off and on again, and same at the kill switch. After several tries (without touching or moving anything) the power was back.
What I didn't do was to look at the tank panel to see if all the lights went out when the starter switch didn't operate, so I will repeat the procedure (although I didn't hear the fuel priming).
I will find my old plugs and test again. Maybe I was just unlucky with the plugs, but the kill switch is a mystery.
By the way, the bike has no fuel manager. The only mods are the after market pipes.
I've just been out to the bike.
I checked the fuses. All good (visual inspection only, I'll redo that with multi-meter).
On the left side bike a three slot fuse box with 30 amp fuses in two slots. The third (the right of the three) is empty. For some reason this fuse box points out towards the rear wheel and all three covers were open. When I go out again I will make sure everything is clean and close the covers/lids.
I checked the two-pin connector all all looks in good condition (I'll double check with multi-meter for breaks, but definitely no sign of heat/melting).
On the right side of the bike I checked all the fuses (10 and 20 amps) and all look in good shape (I'll use the multimeter later).
I pulled the plugs. All wet.
With the pulled plugs connected and touching the cylinders I pressed the starter button. Sparks from two plugs only. I swapped them round to different HT leads on other cylinders and consistently only those same two plugs fired, the other two had no spark wherever they were put. I hadn't thought of failed plugs because they only have 1000 miles on them.
BUT while I was testing the plugs for sparks there was another symptom, something new. I pressed the starter to test for sparks then suddenly NOTHING. No power to the starter, no sound of the fuel pump priming, nothing. The battery is good and tested and charged only last week with good firm connections and a coating of dialectic grease, and the nearby ground point down to bare metal. I turned the key in the ignition switch to off and on again, and same at the kill switch. After several tries (without touching or moving anything) the power was back.
What I didn't do was to look at the tank panel to see if all the lights went out when the starter switch didn't operate, so I will repeat the procedure (although I didn't hear the fuel priming).
I will find my old plugs and test again. Maybe I was just unlucky with the plugs, but the kill switch is a mystery.
I omitted a word, "fuel pressure regulator" should be checked. There have been a a few cases where Ignition switch or four pin connector failed. One failure in the battery cable with the small wire. When in doubt add a new ground wire. Check voltage on the Black/white wire. Look at the diagrams.
Thanks Hans&Feet, I'll lift the tank again and look for the fuel pressure regulator and for leaks (Are these things repairable or just replace? I will order a replacement anyway).
I'll work my way through the wiring diagrams, check the voltage to the coils (B/W wires) and I'll add a new ground wire, but do I have it right, you mean from the coil to ground? (sorry Hans&Feet I am just starting out on learning about the wiring stuff).
Ok, here goes, I'm out there again.
I'll work my way through the wiring diagrams, check the voltage to the coils (B/W wires) and I'll add a new ground wire, but do I have it right, you mean from the coil to ground? (sorry Hans&Feet I am just starting out on learning about the wiring stuff).
Ok, here goes, I'm out there again.
A new Ground wire from Negative battery post to the frame or directly to where the 4 wire Common Electronics Ground bolt is.
Fuel pressure regulator, most have expired..
Fuel pressure regulator, most have expired..
VTX1800 fuel pressure regulator | Bareass Choppers Motorcycle Tech Pages
Because of the outbreak of fuel pressure regulator failures on Honda VTX 1800's, I wrote this guide for diagnosing and fixing the problem.
tech.bareasschoppers.com
I began by trying to start the bike. No life, not even a pop or two. I pulled the plugs again, they were all four wet but noted that all for sparked when I turned the motor.
With the tank removed again (and the battery on charge after so many turns of the starter) I checked and noted continuity from both both coil B/W wires to the PCB and negatives to the ground. I also noted continuity from the three pin connector from the fuel pump to the PCB.
I prepared a new ground wire for the battery to ground. I'll fit that tomorrow. I ran out of time (new neighbours distraction, beers, pizza and that was it for the day) so I didn't yet check the resistance of the coils. I have sourced a fuel pressure regulator though. Option of delivery next week or I go and pick it up myself. So I am set for a drive tomorrow.
I read the Bareass instruction on fitting the FPR, which are very clear and I think I'll be able to install it. If that solves the problem I will be sure to change the engine oil as Bareass advices.
With the tank removed again (and the battery on charge after so many turns of the starter) I checked and noted continuity from both both coil B/W wires to the PCB and negatives to the ground. I also noted continuity from the three pin connector from the fuel pump to the PCB.
I prepared a new ground wire for the battery to ground. I'll fit that tomorrow. I ran out of time (new neighbours distraction, beers, pizza and that was it for the day) so I didn't yet check the resistance of the coils. I have sourced a fuel pressure regulator though. Option of delivery next week or I go and pick it up myself. So I am set for a drive tomorrow.
I read the Bareass instruction on fitting the FPR, which are very clear and I think I'll be able to install it. If that solves the problem I will be sure to change the engine oil as Bareass advices.
The cam pulse generator is located on the front cylinder head, left side, just behind the radiator. If the connector has any corrosion or has become loose the bike won't start. It's worth a look.
I only had an hour of light when I got back with a new fuel pressure regulator, First I checked the cam pulse regulator connection (front cylinder, left side behind the radiator and it was in good condition and firmly connected). I fitted the FPR put the tank back on, and switched on. The fuel pump primed, I pressed the starter but nothing.
After a few tries I pulled the plugs again and all four were sparking when I pressed the starter.
Running back over the symptoms from when it last was running perfectly I removed the tank and seat and adjusted the valve settings. I double and treble checked the gaps were set properly with each cylinder on the correct timing mark. The bike started perfectly. I had no time to ride so over the next few days I started the bike regularly and it started without hesitation but I did notice backfires and after a few more days it dropped to just the rear cylinder. The front left plug was wet. Then the bike wouldn't start at all and that's where I am.
Reading through various posts on the site I get this down to needing compression, fuel and ignition.
Compression? I don't have any reason to think the engine has lost any compression. It was running perfectly smoothly one minute, then backfires, loss of front cylinder then both cylinders.
Fuel? the pump is priming and even spit out fuel yesterday when I didn't tighten the 17mm socket on the fuel line when I put the tank back on. So the pump is working and I put on a brand new OEM fuel pressure regulator all connected. There is enough good new fuel in the tank.
Ignition? the coils are grounded properly and both checked, and all four plugs are sparking.
I will take the tank off again and retrace my steps.
The one thing that always worries me is putting the tank back on and disturbing or damaging some of the wiring harness. I must have disturbed something because yesterday I noticed the right indicators are flashing quicker. The previous owner installed new indicators and made a bit of a rats nest under the tank front leftside and in the headlamp.
Will a faulty or dirty starter/kill switch assembly on the handlebars be the cause?
I'll be out there first thing taking off the tank and checking every connection I can see.
After a few tries I pulled the plugs again and all four were sparking when I pressed the starter.
Running back over the symptoms from when it last was running perfectly I removed the tank and seat and adjusted the valve settings. I double and treble checked the gaps were set properly with each cylinder on the correct timing mark. The bike started perfectly. I had no time to ride so over the next few days I started the bike regularly and it started without hesitation but I did notice backfires and after a few more days it dropped to just the rear cylinder. The front left plug was wet. Then the bike wouldn't start at all and that's where I am.
Reading through various posts on the site I get this down to needing compression, fuel and ignition.
Compression? I don't have any reason to think the engine has lost any compression. It was running perfectly smoothly one minute, then backfires, loss of front cylinder then both cylinders.
Fuel? the pump is priming and even spit out fuel yesterday when I didn't tighten the 17mm socket on the fuel line when I put the tank back on. So the pump is working and I put on a brand new OEM fuel pressure regulator all connected. There is enough good new fuel in the tank.
Ignition? the coils are grounded properly and both checked, and all four plugs are sparking.
I will take the tank off again and retrace my steps.
The one thing that always worries me is putting the tank back on and disturbing or damaging some of the wiring harness. I must have disturbed something because yesterday I noticed the right indicators are flashing quicker. The previous owner installed new indicators and made a bit of a rats nest under the tank front leftside and in the headlamp.
Will a faulty or dirty starter/kill switch assembly on the handlebars be the cause?
I'll be out there first thing taking off the tank and checking every connection I can see.
Did you remove the dust cap before installing the FPR??
Yes, rubber dust cap removed before installing, leaving just the rubber o-ring.
The starter switch can be opened, cleaned and lubed.
The starter switch also opens the headlight contacts.
The continuous current and then dirt+grease create a poor connection and things get hot.
A thread in the Howto Step by Step to clean & lube switch. "Rattlebars" a shop that posted it.
1st Gen 1800 Ground system has issues.
If all else fails, put tranny in Neutral and place a screwdriver across the studs of the starter relay.
A few sparks and cranking should take place.
Required reading for 1800 owners>> Honda Programmable FI - How it works.pdf
In this thread>> 1800 »How ECU and Programmed Fuel Injection Works
The starter switch also opens the headlight contacts.
The continuous current and then dirt+grease create a poor connection and things get hot.
A thread in the Howto Step by Step to clean & lube switch. "Rattlebars" a shop that posted it.
1st Gen 1800 Ground system has issues.
If all else fails, put tranny in Neutral and place a screwdriver across the studs of the starter relay.
A few sparks and cranking should take place.
Required reading for 1800 owners>> Honda Programmable FI - How it works.pdf
In this thread>> 1800 »How ECU and Programmed Fuel Injection Works
I found instructions on the starter switch and opened it up, dismantled it, learned how it worked (simple but very clever) added dielectric grease and reassembled.
It's no use me just staring at the bike wondering what the problem could be, I'm just going to go back to where I knew it was running perfectly, so tomorrow I'll start it all again and check the valves just in case I did something really obviously wrong there. Then I'll check all the connectors again and eliminate as may wires as I can as being broken circuit suspects. I'm feeling a bit down hearing all the bikes rumbling in the distance but actually I'm learning a lot. At first those wiring diagrams were just a blur to me, but now I see the sense in it all and just follow each circuit through from one end to the other.
Ok, the first generation ground issue. I will check and redo the grounding points and the extra wire I put in from from the battery negative to the frame (actually at the rear coil frame mount). Is there anywhere I should maybe add another ground wire?
My reading for tonight is the fuel injection system. I love these bikes and I just want to get back riding so I am determined to solve this problem. I followed your link to your post from July 2016, downloaded the pdf attachment, but the link in that post (http://www.maultechatv.com/techguid...tion/Honda Programmable FI - How it works.pdf) won't open for me. Is there another way to this information?
The screwdriver and the starter relay technique sounds interesting. I just checked out how relays work (something else that's simple but very clever) so I see how that bypasses the relay system with power coming directly from the battery.
It's no use me just staring at the bike wondering what the problem could be, I'm just going to go back to where I knew it was running perfectly, so tomorrow I'll start it all again and check the valves just in case I did something really obviously wrong there. Then I'll check all the connectors again and eliminate as may wires as I can as being broken circuit suspects. I'm feeling a bit down hearing all the bikes rumbling in the distance but actually I'm learning a lot. At first those wiring diagrams were just a blur to me, but now I see the sense in it all and just follow each circuit through from one end to the other.
Ok, the first generation ground issue. I will check and redo the grounding points and the extra wire I put in from from the battery negative to the frame (actually at the rear coil frame mount). Is there anywhere I should maybe add another ground wire?
My reading for tonight is the fuel injection system. I love these bikes and I just want to get back riding so I am determined to solve this problem. I followed your link to your post from July 2016, downloaded the pdf attachment, but the link in that post (http://www.maultechatv.com/techguid...tion/Honda Programmable FI - How it works.pdf) won't open for me. Is there another way to this information?
The screwdriver and the starter relay technique sounds interesting. I just checked out how relays work (something else that's simple but very clever) so I see how that bypasses the relay system with power coming directly from the battery.
Update, the pdf attachment was the information I needed. I read it all and understand the system quite well in theory, but I haven't seen the parts. There have been no flashing of the MIL except when I have disconnected the filter and the air pressure sensor.
Air box has air temperature sensor. Measure that Air Temp sensor.
Shown as IAT sensor on the schematic... Compare to spec in SM.
I remembered that someone had a IAT with Ohms way off.
One member mentioned on another thread about using a short burst of cranking.
Continuous cranking takes the battery down.
Test instrument: what is the voltage on the Black/white wire when IGN sw turned on.
Operate the Kill switch several times. What is the voltage when cranking???
Shown as IAT sensor on the schematic... Compare to spec in SM.
I remembered that someone had a IAT with Ohms way off.
One member mentioned on another thread about using a short burst of cranking.
Continuous cranking takes the battery down.
Test instrument: what is the voltage on the Black/white wire when IGN sw turned on.
Operate the Kill switch several times. What is the voltage when cranking???
I will make sure the battery is charged. I have been cranking the engine so yes, it will drain, thanks.
I need to test for any voltage drop on my circuits from the PCM. Do I have the method right? which is (as I see it) to follow the wiring diagram to identify the correct wire and connection into the PCM (the B/W wire is from the coils). With the multi-meter set to 'volts' I probe the positive lead of the multi-meter into the B/W connector at the PCM. And then with the ignition switched on (and the switch on at the handlebars) I should put the negative probe of the multi-meter to the positive terminal of the battery and note the reading. Ok, now comes the tricky bit. If the connection is in good shape what should the reading be? What is the accepted drop in voltage? Do I have to then calculate voltage drop against the resistance in ohms of the coils? I think I need a little help as I learn this technical part.
I can then check the ground circuits from the PCM in the same way but but this time probing the wire that enters the PCM from the ground of the coil (for example, but others as well). Then with the ignition on as previously) touch the negative of the multi-meter to the negative terminal of the battery and note the readings.
I read around this subject last night and I see that excessive voltage drop picks up loose connections, corrosion in the circuit and broken wires I might have cause refitting the tank so many times and the harness under there having been 'adapted' by the PO. Voltage drop then can cause a delayed reaction in the PCM which means that circuits controlled by the PCM will not work properly or even not at all.
That makes a lot of sense now, and putting that together with the information you gave me on the FI system I'm beginning to understand what goes on and what can go wrong.
So, have I got the above method right? I don't want to go sticking probes in the PCM and to the battery terminals without being sure that I am doing the right thing.
Last thing is that you say: 'Operate the Kill switch several times. What is the voltage when cranking???'
Ok, is that operate the kill switch with ignition on or off?
And the method then is to find the correct positive wires from the starter kill switch assembly, insert positive multi-meter probe into where that wire/s enter the PCM, negative multimer probe to the positive battery terminal. That puts the multi-meter into the positive part of the circuit and any voltage drop can be identified.
To be sure do I probe the starter switch wire as it enters the PCM or the kill switch wire? I will do both anyway and work out how to hold the multi-meter with two hands and use the other one to operate the starter button to crank it over.
I need to test for any voltage drop on my circuits from the PCM. Do I have the method right? which is (as I see it) to follow the wiring diagram to identify the correct wire and connection into the PCM (the B/W wire is from the coils). With the multi-meter set to 'volts' I probe the positive lead of the multi-meter into the B/W connector at the PCM. And then with the ignition switched on (and the switch on at the handlebars) I should put the negative probe of the multi-meter to the positive terminal of the battery and note the reading. Ok, now comes the tricky bit. If the connection is in good shape what should the reading be? What is the accepted drop in voltage? Do I have to then calculate voltage drop against the resistance in ohms of the coils? I think I need a little help as I learn this technical part.
I can then check the ground circuits from the PCM in the same way but but this time probing the wire that enters the PCM from the ground of the coil (for example, but others as well). Then with the ignition on as previously) touch the negative of the multi-meter to the negative terminal of the battery and note the readings.
I read around this subject last night and I see that excessive voltage drop picks up loose connections, corrosion in the circuit and broken wires I might have cause refitting the tank so many times and the harness under there having been 'adapted' by the PO. Voltage drop then can cause a delayed reaction in the PCM which means that circuits controlled by the PCM will not work properly or even not at all.
That makes a lot of sense now, and putting that together with the information you gave me on the FI system I'm beginning to understand what goes on and what can go wrong.
So, have I got the above method right? I don't want to go sticking probes in the PCM and to the battery terminals without being sure that I am doing the right thing.
Last thing is that you say: 'Operate the Kill switch several times. What is the voltage when cranking???'
Ok, is that operate the kill switch with ignition on or off?
And the method then is to find the correct positive wires from the starter kill switch assembly, insert positive multi-meter probe into where that wire/s enter the PCM, negative multimer probe to the positive battery terminal. That puts the multi-meter into the positive part of the circuit and any voltage drop can be identified.
To be sure do I probe the starter switch wire as it enters the PCM or the kill switch wire? I will do both anyway and work out how to hold the multi-meter with two hands and use the other one to operate the starter button to crank it over.
Take the Black probe and place it on a good ground connection. A clip lead will do also(clips on both ends). Red probe - Check voltage on the wires of interest.
Red/white +12v battery voltage, ESR (Engine Stop Relay) Bl/W wires to coils/injectors/ECM
Check the resistance of the IAT. XX Ohms across the device.
During active testing a small needle can be used to probe the voltage.
For static testing you can remove the ECM connectors to check continuity to sensors.
The ECM has a +5v sensor and sensor Ground planet.
TPS is a 5k potentiometer, you check resistance(voltage OFF OR you can check for voltage with IGN ON.
Some sensors generate voltage, some you can check for resistance (ohms).
Resistance test----part isolated, no voltage on system.
Voltage tests--Power ON condition.
Service manual has tests for many items. They use a test cable for breakout.
We have to use needles. Peak voltage tests--easy to make, a diode and a capacitor.
Red/white +12v battery voltage, ESR (Engine Stop Relay) Bl/W wires to coils/injectors/ECM
Check the resistance of the IAT. XX Ohms across the device.
During active testing a small needle can be used to probe the voltage.
For static testing you can remove the ECM connectors to check continuity to sensors.
The ECM has a +5v sensor and sensor Ground planet.
TPS is a 5k potentiometer, you check resistance(voltage OFF OR you can check for voltage with IGN ON.
Some sensors generate voltage, some you can check for resistance (ohms).
Resistance test----part isolated, no voltage on system.
Voltage tests--Power ON condition.
Service manual has tests for many items. They use a test cable for breakout.
We have to use needles. Peak voltage tests--easy to make, a diode and a capacitor.
Family stuff and work got in the way of getting the bike back on the road but over the weekend I had a couple of hours to start again going through the wiring diagrams and checking some of those wires. I wanted to see if the bike would start so with the tank loose and raised on a block at the seat end I started the engine, fired on the button and ran perfectly. Then again later. Next day the same thing, not a blip on the throttle. But when I fastened down the tank and but everything back together and started the engine the RPMs dropped and it soon started popping then back on one cylinder. The front left plug was wet. I know that these early models are prone to grounding issues so I will do the ground check a third time and double-up on grounding wires where I can. If it isn't a poor ground somewhere then I'll have to find what is affecting the spark to the front left plug. I've ordered a roll of HT cable and replace the lead to the front left plug in case it is something a simple as a failed HT lead. I've ordered an inline spark tester too, just to make life easier. This weekend I will get back to finding the fault.
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