yd328

I'm trying to help out a fellow c4 owner with his car. It's a 94 vert, 6sp w/103K. There's not much of maintenance history, no FSM, it's new to him. The car does turn over and stumbles for a moment but will not start or idle. You can smell fuel from the attempt to start.
This is what I have checked so far.
Fuel pressure, 40lbs cranking. It took a couple of attempts of key on only at first to get to the 40lbs w/just key on.
injectors all ohmed@12.5
No fuel coming from the fp regulator vac line.
5 out of 8 injectors show they are getting pulses via noid light
No codes
TPS is .62 volts
IAC at 139 counts key on
no spark at plug
fuses checked
I couldn't ohm the coil, didn't have the right probes.
I have a 95 FSM, not sure if the wiring for the coil, icm, and opti are the same.
Battery now has to be charged from starting attempt.

Thanks for any help or thoughts

Gary

Tom400CFI

Sounds like you have a scan tool. Use it to view your "hi res" and "low res" signals from the distributor, and/or your tach signal while cranking. If you have no, or erratic signals, you have no spark b/c the pick up (optical sensor) in your distributor is failing or dirty.

yd328

Thanks,
i’m using A snap on mt2500. I should be able to see tach, not sure about hi-lo res

gary

woody3882

Not saying that this is your problem, but I have the same year and spent a long time before I realized that the TPS should be .54 not the .62 you are getting.. I also found that they are extremely sensitive and if off even slightly they will make your life miserable..(learned from the school of hard knocks) You might have a few minor problems to straighten out but the TPS is where I would start, it's pulse sets everything else in motion. Been there, Done that.
Good luck
Woody

pcolt94

Check the temp sensor in the water pump. If not connected or open, the injector pulses will be at max and will flood (as you smell fuel). If you check the digital water temperature and it looks OK, the temp sensor is probably OK (without having to ohm it out). PCM sees this resistance for A/F.

Check the drive for the ICM (as per 95 FSM ok), probably white wire terminal "B" to see if it has the 1-4 VAC on it while cranking.

yd328

I’ll reset the tps to .54v. The scanned temp was reading the same as outside temp so I think we should be good there.

Thanks
Gary

woody3882

I hope the .54 works for you, When i installed a new TPS it had fixed/non adjustable screw holes and the reading set at .67 after the problem continued and hours of research, I filed the screw holes to elongate them so I could adjust the reading, I found that .54 was the sweet spot and have never had a problem since
TIP: remember when you elongate the hoes use a file, NOT a drill, the drill is to aggressive and will crack the plastic. (another expensive lesson learned) Also, when you elongate the holes, the left hole elongates left to right, and the right hole elongates up and down. When you look at it you will understand what I mean, Dont forget drop of Bue loc-tite.
Let us know how you make out, best of Luck
Woody