1992 Chev Lumina - 3.1L No Start

[nickscarcare]

I have a 92 lumina, and it was brought in for a no start, cranks ok, has spark and injector pulse at the 2 injectors that I can reach.

Fuel pressure is 38 psi koeo or cranking. Wasn't there another connector somewhere that you could ohm test the injectors all at once. I believe there was and the reading was like 2-4 ohms?? The 2 I can get to have 12.4 ohms, so they should be good. This car has been sitting for a couple of days so its not a hot start issue. I pulled the egr valve off and have bareley any back pressure cranking. The scanner shows 300 rpm while cranking.

[liljoe]

Best I remember I checked them at the PCM connector, it is a batch fire set up with two banks, both should read the same but I do not remember what the exact spec is.....

[steven kiser]

If you spray starting fluid into the intake will it fire? Just because you have pressure it may not be gasoline. If you have impulse at the two injectors you can reach it should at least sputter. Basically my quick no start diagnosis always includes a quick spray. I check for a good spark, blue and a good 1.5 jump, fuel pressure and smell. I have had a rare time or two where i wouldn't get even a sputter with a plugged cat. Yank out an 02.

[Tim Martin]

Assuming that there is good compression my guess is it may be the ignition module. I have seen more than one have spark and fuel injector pulse and not start. Turns out to be the ignition module. I suspect that the timing of the spark and injector pulse was incorrect. Fuel pressure is slightly below specs of 41-47 psi although it should almost start at that point. The other thing, beings it is of that era, you can't rule out a faulty PCM. They were notorious failures.

[rytek]

I do recall replacing many, many coil packs & modules on these beasties. It's been so long since I've seen on I am getting misty-eyed...

The modules can trigger normal-looking spark but not send it at the correct time.

Are you using a gap-type spark plug tester (GM style or adjustable) or one of those noid light types that go inline with the plug wire? I always like to see the color and strength of the spark.

Did you verify proper crank sensor signal?

I agree with Kiser that using starter fluid will often verify the fuel delivery aspect. Making sure there's actually gas in the tank is key. I have also seen plenty of fuel pumps produce pressure but not send enough volume of fuel.

Is the coolant sensor reading correctly?

Just my initial thoughts. Keep digging and you'll find the cause.

[nickscarcare]

Well Tim was the closest with the compression issue. Engine sounded like it was cranking ok, a little different, so I did a compression test, and guess what, lifted the front valve cover and no rocker movement. Called the customer and now he tells me that oh yea it was making a rattling or clunking noise right before it quit. Got to love the lack of info they give you. Well considering this guy has no money and this car has 240k rounds on it, I am waiting to see what he does here. I had to discount a little a month ago when it was here for the fuel pressure regulator, just to get the job. Not a big discount but enough. I guess I will let everyone know if he decides to dig into the timing chain. Thanks for the replies.

[Tim Martin]

Got a 91 Olds Cutlass in here as we speak with the exact same issue. Owner is low on funds and can't seem to decide what to do. So we pushed the car out on the to do lot.

[Tim Martin]

Got to love the lack of info they give you.

Yea, a little like some shops that call and want some advice. They want an expert answer without giving all the symptoms. Now they are both sounding like real customers. I ask what vacuum does it have? Oh, it has good vacuum. What's fuel pressure? Oh, didn't put a gauge on it but the pump runs.

Gotta love it. We need to somehow figure out how to charge for mind reading exercise.

[steven kiser]

Off point here but within limits. As of Jan first i put a sign n the wall and notified owners of vehicles that are here of a new policy. Any vehicle left here while decisions are made gets three free days, after that storage in applied. Any vehicle left here for more than three days after repairs are made is charges storage. Here in the biggie, On my lot right now i have two trucks sitting here owned by people that have me do work their fleet mechanic can't do. Both were authorized and the orders combined exceeds 14 grand. I have an invoice that i'm paying Saturday and my have to tap into my line of credit. Not a big deal, i hit it a few times a year because of issues like this. I explained to the truck owners that i'm not releasing them until i get paid, they will be charged storage of 100 bucks a week and if not paid by tomorrow with check clearing and funds in my account will be charged with the amount i'm charged for the line of credit. I was going over my tax information a few days ago and i paid almost 5 grand in interest and fees for using my line of credit.