No start; give me some troubleshooting ideas.
- Thread starter Timbo
- Start date
Re: No start; give me some troubleshooting ideas.
Hey Tim ,, I use a small paperclip and straighten out the last wrap so you have a little probe about 1 inch long ,, then probe the middle wire and connect test lead from the fluke meter then ground the other lead .. you can carefully slide the paper clip into the connector next to the middle wire ,, that works for me ..
Jon
Hey Tim ,, I use a small paperclip and straighten out the last wrap so you have a little probe about 1 inch long ,, then probe the middle wire and connect test lead from the fluke meter then ground the other lead .. you can carefully slide the paper clip into the connector next to the middle wire ,, that works for me ..
Jon
SBNova
New member
Re: No start; give me some troubleshooting ideas.
Yeah just probe the wires like AKty92 said, or just "stab" the wires with the voltmeters probes. You mentioned that you think you lost power to the ECM, have you tried pulling codes? Have you seen the check engine light come on? It should come on with the key on/engine off.
Yeah just probe the wires like AKty92 said, or just "stab" the wires with the voltmeters probes. You mentioned that you think you lost power to the ECM, have you tried pulling codes? Have you seen the check engine light come on? It should come on with the key on/engine off.
Timbo
SyTy Stalker
Re: No start; give me some troubleshooting ideas.
Results of the TPS test:
Black wire: 0.021v
Blue wire: 0.850v
Green wire: 5.02v
Is 0.021v enough to mean I have a bad ground, since there is supposed to be no voltage to that wire?
At the very least it's misadjusted since the blue wire is supposed to be at 0.54v. I'll have to have someone else work the throttle while I test it to see if the blue wire varies in voltage.
Results of the TPS test:
Black wire: 0.021v
Blue wire: 0.850v
Green wire: 5.02v
Is 0.021v enough to mean I have a bad ground, since there is supposed to be no voltage to that wire?
At the very least it's misadjusted since the blue wire is supposed to be at 0.54v. I'll have to have someone else work the throttle while I test it to see if the blue wire varies in voltage.
Re: No start; give me some troubleshooting ideas.
Go ahead and pull the linkage at the throttle body ,, its not too hard to hold the test probe while doing it ,, And does the computer use a cam sensor or crank sensor ,, If the computer in my GN doesnt see the engine rotating it wont turn on the injection ,,( I think thats right ???) anyway thats all I can think of ..
Jon
Go ahead and pull the linkage at the throttle body ,, its not too hard to hold the test probe while doing it ,, And does the computer use a cam sensor or crank sensor ,, If the computer in my GN doesnt see the engine rotating it wont turn on the injection ,,( I think thats right ???) anyway thats all I can think of ..
Jon
Timbo
SyTy Stalker
Re: No start; give me some troubleshooting ideas.
Alright, with the TPS connected, and the throttle opening, I have a range from 0.85 - 4.5 volts on the blue wire. The green and black wires stay at 5.02 and 0.021 volts respectively.
I tried to pull codes, but the only thing that flashed was 12.
Alright, with the TPS connected, and the throttle opening, I have a range from 0.85 - 4.5 volts on the blue wire. The green and black wires stay at 5.02 and 0.021 volts respectively.
I tried to pull codes, but the only thing that flashed was 12.
Don W.
Stab it and steer it
Re: No start; give me some troubleshooting ideas.
Looking at the Sy manual again, it looks like the black wire is ground so check continuity of this wire to ground.
The grey wire (might be a manual mistake if yours is green) is 5 volts from the ECM which would be correct.
The blue wire should vary from .36-.44 volts in idle position to 5.0 (or the grey wire volts) at full throttle position.
So except for a pos faulty ground it looks to me like your TPS is good. Double check that the black wire shows continuity to ground. You should be able to light a test light between grey(green?) and black. Somebody correct me but it looks, in the manual, like this wire grounds through the ECM so make sure the ECM itself has a good ground.:tup:
Looking at the Sy manual again, it looks like the black wire is ground so check continuity of this wire to ground.
The grey wire (might be a manual mistake if yours is green) is 5 volts from the ECM which would be correct.
The blue wire should vary from .36-.44 volts in idle position to 5.0 (or the grey wire volts) at full throttle position.
So except for a pos faulty ground it looks to me like your TPS is good. Double check that the black wire shows continuity to ground. You should be able to light a test light between grey(green?) and black. Somebody correct me but it looks, in the manual, like this wire grounds through the ECM so make sure the ECM itself has a good ground.:tup:
Timbo
SyTy Stalker
Re: No start; give me some troubleshooting ideas.
Big update...
I borrowed a stock ECM from another member, and plugged it in. The truck started and ran fine. Now how do I figure out what's wrong with my ECM? I assume since I smelled something burning that something in it is fried. Do I have to get a new one and mod it for my chip and injectors like the old one is?
Big update...
I borrowed a stock ECM from another member, and plugged it in. The truck started and ran fine. Now how do I figure out what's wrong with my ECM? I assume since I smelled something burning that something in it is fried. Do I have to get a new one and mod it for my chip and injectors like the old one is?
Syclone#1992
SyTy.net Moderator
Re: No start; give me some troubleshooting ideas.
I would guess that would be your best bet....something must have fried the other one.
Thats good you got it started!
Timbo said:
I would guess that would be your best bet....something must have fried the other one.
Thats good you got it started!
Timbo
SyTy Stalker
Re: No start; give me some troubleshooting ideas.
I looked over my ECM, and it looks like there's some corrosion around where the injector drivers connect to the board. I tried to clean it up some, but it didn't really help. I think that's where it overheated and my board's probably no good now.
It does feel really good to hear my Ty start up and run though.
Oh yeah, I broke on of the screws off of the TPS when I was adjusting it :roll:
I looked over my ECM, and it looks like there's some corrosion around where the injector drivers connect to the board. I tried to clean it up some, but it didn't really help. I think that's where it overheated and my board's probably no good now.
It does feel really good to hear my Ty start up and run though.
Oh yeah, I broke on of the screws off of the TPS when I was adjusting it :roll:
Timbo
SyTy Stalker
Re: No start; give me some troubleshooting ideas.
I had AKty92 solder some Fairchild MOSFETs into another ECM (since I suck at soldering) and swapped my chip over. The Ty runs just like it should. I pulled it out of the garage today (first time I've driven it since December '04), and now I'm going to go wash it. Thanks to Ak sy for donating his old ECM, and to AKty92 for helping with the mod.
I had AKty92 solder some Fairchild MOSFETs into another ECM (since I suck at soldering) and swapped my chip over. The Ty runs just like it should. I pulled it out of the garage today (first time I've driven it since December '04), and now I'm going to go wash it. Thanks to Ak sy for donating his old ECM, and to AKty92 for helping with the mod.