Gators91TransAm - I'm sorry in that I played a part in screwing your last thread, let me recap:

"My wife was driving the car (91 TA w/305) and it hesitated. She let off the gas, then it backfired when she gave it gas again. She pulled over, shut it off, and it would not start again.

The motor turns, and I can hear the fuel pump initializing. But it won't catch. "

You replaced the ignition module and plugs. We ruled out the timing chain being broken.

We are now waiting to see if you got any codes and if you can check the fuel pressure. Also a check on the EGR was suggested as well as a verification of TDC and rotor position.

Hope I didn't miss anything, and again I apologise for partaking in the thread hijack.

 

You should start with getting a fuel pressure gauge and check it at the rail near the distributor, all because you hear the pump doesnt mean that it still is capable of building up enough pressure to fire a group of injectors enough for the motor to fire.

If you dont have a fuel pressure gauge maybe this might help with out the gauge.

I personally would get someone to turn your accessories to the ON position allow the pump to prime(3secs) and then press the schraeder valve on the fuel rail if fuel just trickles out your fuel pumps bad if it has very strong pressure and hits the roof of your hood then maybe not.( wearing safety glasses wont hurt gas in your eye will ) << note the closed eye...lol

 

I have not pulled the codes yet, but a buddy is bringing over his lil scan tool tomorrow to help with that.

Until then, I'll try the fuel check you suggested and see what we get.

Thanks again!

 

Checking the codes takes 5 minutes and a paper clip, that's why I suggested it Read about it on the FAQ https://www.thirdgen.org/newdesign/faq/thirdgen.shtml

 

Okay...gave me '12', which is "No reference pulses to ECM".

Does this mean the ECM is bad? Or...? Can I test it?

This sucks, but explains the no start condition, eh?

 

who made that list? code 12 means no problems, on every OBDI gm ive ever worked on

 

The list is correct. Nor reference pulses from the distributor to the ECM. Makes perfect sense if you stop and think about it.

 

Meaning that, according to the OBD, nothing is wrong? Or...? I don't know enough about how the system works to draw an accurate conclusion.

I suppose I'll know more once I get the scan tool hooked up.

 

There is no reference pulse coming from the dizzy because the dizzy is no workie if the motor isn't running.

Test the fuel pressure, and pull a few plugs and see what they say. Was it running really rich just before it happened? Whenit turns over is there a strong smell of fuel?

 

I don't know if it was running really rich. Fuel mileage and performance didn't change, as far as I can tell.

I pulled the plugs (replaced, actually), and all showed signs of a normal burn. They were out of gap based on age, but were fine other than that.

Yes, there is a strong smell of fuel when trying to start it.

 

Gator do you know how to confirm that you are getting spark to your spark plugs ?? by using a jumper wire ??
did you try the fuel pressure trick yet??

 

We used the old screwdriver and a ground trick for the spark. What fuel pressure trick are you talking about? I'm gonna try and do some more tonight...

 

Scroll up to where i posted you should get a fuel pressure gauge, then read below that.

 

Gotcha. I wasn't sure if that was the 'trick' you were referring to. I plan on trying that tonight, and I'll let you know what I find.

 

Just in case you have eliminated spark as the problem, seeing a spark doesn't mean anything if the car won't start You need to use a spark checker to make sure you've got adequate spark, your coil or some other ignition component could be fried.

 

spark checker??????

NOOOOOOOOOTTTTTTTTTT

If somthing in his ignition were fried he wouldnt get a spark at all.!

 

Never heard of a weak spark huh?

 

Okay, where is the schraeder valve located? It's TPI, and I've checked both rails but don't see it...

 

The schraeder valve is located on top the passenger side fuel rail near the back. Looks like a tire valve stem and might have a back dust cap on it.

 

Yeah what he said..Its behind the small vacume hose that hooks near the back corner of the plenum pass. side of coarse.
Mine has a small aluminum cap .

 

Found it. I'll try that in a few minutes and post the results.

Thanks for the help.

 

Shot fuel out, but it was just a small shot...I guess I should try and find a fuel pressure gauge to do this correctly, but it apears the pressure is good.

So far, I've replaced the ignition module, cap and rotor, plugs. I've verified spark (but not with a spark checker) and fuel (though not with a pressure gauge). I've checked codes, got repeating 12. That's it, and I'm stumped. Car will turn over fine, but will not start.

Damn I've never had a problem kick my *** like this before. I'll be pissed if I have to take it to a shop...lol...

 

What's normal spark? I got a spark checker, one of the screw types with an alligator clip. The screw is adjustable out to 40, but I'm curious what would constitute a 'good' spark.

Anyone?

 

A big fat blue spark.

 

Gotcha... I just didn't know if the numbers meant anything, if it should arc a certain amount, etc. I'll look for 'a big fat blue spark'.

 

Got it running...with the spark tester hooked up, I was getting a very weak spark. I replaced the coil pack, and she cranked right up.

I appreciate all of the help you guys have given me with this. I feel like an idiot that it was something so simple, but at least I got a good tune-up out of the deal. Total cost was prob. around $60, so I don't feel like I just kept throwing money at it. I just wish I'd gotten the spark tester earlier so I'd have been able to better gauge the spark.

Thanks again, guys! Until next time...

 

Yeah, just chalk those other items up as maintenence that probably was needed anyway..

 

Can Anybody help me i am having a problem my car will not start i dont hear the fuel pump prime i found out that the fuel pump relay was bad and i i replaced it.my car then started and was running but then the next mourning my fuel pump wouldn't prime so can somebody give me ideas or helpfull information so i could get my car running for work tomorrow
thanks in advance

 

Um yeah its your fuel pump going out. Not your relay...Get a fuel pressure gauge and check the fuel pressure on the schraeder valve near the distributor on the passengers side I will bet the pressure is weak & drops immediately

rob