Truck Wont Start, HELP!! I've Tried Everything!

Mustang78

New Member
Feb 8, 2006
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Aberdeen, WA
The truck is a 1988 Chevy 3500 1 ton pickup with a 350ci. It would sometimes idle fine, and other times the idle would jump up and down and die if you didnt hold the brake and gas at the same time, it is an ex-state truck so i know it spent a lot of it's time idleing on the side of the road(only 40K original miles), the problem has been steadily getting worse until yesterday when it wouldent even start, i took a shot in the dark and bought a TPS, which didnt help. Then i hooked it to a home scan-tool and it said there is no signal from the distributor to the ECM, so i bought a hall effect sensor(in the dist.) tonight and that didn't make a speck of difference either, it has fuel spraying out the injectors(2 of em on top of the intake) and spark from the coil, (not sure about spark from the distributor), any help would be GREATLY appreciated, even a shot in the dark could solve the situation, it has been an ongoing problem since we bought the truck a coulpe years ago and it just got worse, but this is the first time it wouldent start, Thanks

~Mark~
 
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Mark, if you check spark right now, do you have any? If not, I'd think about having the ignition module tested.

If you have spark, does that truck doesnt have a Schrader valve does it? I'm thinkin it doesnt and needs only around 15 PSIG for fuel pressure. I only ask because it would be nice to see what kind of FP you have.

Those central injection trucks respond decently to starter fluid (if needed for a quick test).

Good luck.
 
the ignition module is common on them. I drive a 92 Z71 with the same engine and mine did the same thing and that's what it was. I replaced the cap and rotor while I had the cap off. I work in a garage and do one of theese atleast once every other week
 
the ignition module is the black piece with 3 plugs that sits under the rotor and has dielectric grease on the bottom right? i replaced that for 55.00 last night..i get the same code with it plugged it or unplugged, doesn't matter. it's getting plenty of fuel i can see it squirting normally, ir is some kind of electronic issue, i didnt see any frayed or mouse chewed on wires, i checked that computer next to the master cylinder and none of the module wires colors match those that go into that box, or else i would jumped the wire directly to where it should go. we tried starter fluid and it kicks over like one cylinder hits every couple revolutions(it's consistent), Thanks and not sure about the schrader valve, there are a couple electronic boxes on the right side(passenger) of the TPS, what are those?

~Mark~
 
Mark, FWIW I've seen firsthand a set of TBI injectors squirt but it was not enough to allow the truck to idle. The injectors were still visibly flowing fuel but pump volume was down approx 50% (said another way, with this low pressure system very little pressure still allows injectors to squirt). It's not nearly enough to fire though. In that case, ether did make the truck catch for a second (where it would not before) so I had a good idea it was fuel delivery.
I've seen GM fuel adapters that have a schrader valve - they're about 30 bucks and go inline right where the fuel line meets the TBI. Worth their weight in gold if one suspects a fuel issue (I think dropping truck tanks is kind of a pain). Also, on some early trucks, the TBI's themselves were problematic. It's idiosyncrasies like that which make cruising through a GM truck forum kinda nice (just like GM guys might not know that with us, TFI modules and ignition switches are likely and common issues).

Random thoughts. Good luck.
 
we tried starting fluid, and lots of it..still leaning towards a spark issue, is there any more sensors besides the ignition module(in the dist.) that are between the distributor and ECM? it still says it's not getting a signal from dist. to ECM

~Mark~
 
I thought there was some electrical thing on the passenger side firewall where the spout connector is hidden. Its a plastic box. Im just guessing though. My dad has an 88 scottsdale, and its quite picky on running right.
 
Mark, A cap and rotor should not fix the issue for that code.

It's gonna take some component testing to narrow it down however (you really need the truck to fail and start testing for spark, fuel pressure and watching injector flow compared to how it is when healthy).

Just MHO.
Good luck.
 
I'm surprised that you're getting this much response over here. I don't have much else to add to what has been said, but if you don't find what you're looking for, try out fullsizechevy.com. It's a good forum for these trucks, and there's some good guys over there. I have an '89. Good luck.
 
i've looked under that plastic cover and saw the spout connector and what looks like some relay's, i'll check around there after work today and hope we get this figured out, i didnt expect this much response either, but i'm glad(in a way) that other people have problems with these trucks too, haha

~Mark~
 
i didnt expect this much response either, but i'm glad(in a way) that other people have problems with these trucks too, haha

~Mark~
I've never had a problem with mine other than grenading the stock 10 bolt rear when I first got it. Mine has 162k and still runs mint, even the stock 700r4 is still perfect, and the truck has had plenty of abuse since I bought it. They're awesome trucks from what me and my family have experienced. Good luck getting it straightened out.