not sure this is the right place to post this...?

[wontgiveup]

Hello everyone. I am aware that this may not be the right place to post this thread but I didn't see any other topics that were more fitting, and I tried registering on a different forum site but I entered my email wrong and now I can t seem to correct it/register again.

My name is Daniel, and I've got a 1989 GMC S15 2 door with a 2.8L V6 engine. My initial problem was it started stalling while driving, if I let off the gas at all it would die out and I'd have to pop the clutch (its a standard transmission....obviously). I replaced the fuel filter and that seemed to fix the problem. Then a couple days later it cut out while driving and I had to tow it home. It was a crank no start condition.

I first replaced the starter and that didn't do it. Checked for spark (I know I probably should have done that first) and had no spark, so I replaced the ignition coil. Still didn't work. I replaced the Ignition control module (which I had to wire to work, I replaced a 7 pin with an 8 pin). That got me to where I am now, it would crank and start but die immediately unless spraying starter fluid in the throttle body. Might I add it still backfires and I had a small fire in the throttle body because of the starter fluid/backfire. quickly extinguished. I replaced the fuel pump and the fuel pump relay (I believe I replaced the correct one, driver side firewall there are two relays mounted to it. Replaced both.)

I have a friend with an identical parts truck, I have tried using the following parts from it in an attempt to fix mineCV valve, IAC, TPS, Vaccuum regulator valve, Map sensor. I also inspected vacuum lines. I tried the ECU off the spare car and still no luck. Im thinking it could be the ignition switch?

Can someone please help me? I am getting discouraged and frustrated and cannot afford to take it to a mechanic. Thanks in advance.

 

[618 Syndicate]

SO this should probably be moved to the other vehicle builds area, you're asking about a non-GMT400 truck and an engine that was never offered in these trucks in the US.
That said, if there are people here who can help, I'm sure they will, but there may not be very many.
@PlayingWithTBI or @Schurkey got any input?

 

[wontgiveup]

Fair enough. Thanks for your quick, polite response.

 

[Stumpy]

Fuel pump, comes to mind. Maybe on it's way out.

 

[stutaeng]

Fuel pump, comes to mind. Maybe on it's way out.

OP stated he already replaced it.

Probably should of checked for fuel pressure before it was changed. Now we don't know if it was good and he got a lemon, in addition to whatever the original problem may have been...

OP, is there a way to get a fuel pressure guage on the fuel rail or fuel line? I know some of the older generation vehicles don't didn't come with the Schrader valve.

 

[DeCaff2007]

I'd put the correct ignition control module on there first. Then, check all of the ground connections you can find.

 

[Dropped88]

X2 on ignition module the computer uses that to pulse injectors and if it's throwing erratic signals there's no telling what it could be doing.

And fuel pressure should be right around 13psi

 

[PlayingWithTBI]

I'd put the correct ignition control module on there first.

X3 - Use only the correct, quality, replacement parts.

And fuel pressure should be right around 13psi

X2 - check fuel pressure when you turn the KOEO, while cranking, and when it fires.

Then start looking at things like ignition switch, wiring, etc.

 

[wontgiveup]

Awesome. Ive read through lots of forums just have never posted a thread of my own. Not sure why? Very helpful. Yes I was wondering about the control module and had considered putting one like it originally had back in. When I bought it from Autozone the guy who sold it to me swore it was the one for the car and I just needed to re-wire it. It had the same labeled terminals just moved around a bit. So I re-wired it and I asked another employee a few days later and he said no they had the 7 pin and that was the one that came up when he searched for it. Ultimately my fault but thats my excuse anyway.

I have checked most of the ground connections but Im sure there are a few I missed, will check that too. Also will check fuel pressure.

I should have added that the oil pressure sender unit switch (Ive seen different titles) may have an internal leak. I read it could have something to do with it so pulled it and there was oil in the connector. It could have also dripped down from a small oil leak. I cleaned it, dried it and hooked it back up. Will check it again here now. On that subject I read that I can unplug the sensor and it would "bypass" the switch. Can anyone confirm that?

Again everyone thanks for your advice and suggestions. If anyone has any plumbing issues I'd be happy to repay the favor (plumber by trade).

 

[PlayingWithTBI]

On that subject I read that I can unplug the sensor and it would "bypass" the switch. Can anyone confirm that?

The oil pressure switch will bypass the fuel pump relay when it sees ~4 PSI. Here's a schematic from an 88 GMT400, should be the same idea.

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I re-wired it and I asked another employee a few days later and he said no they had the 7 pin and that was the one that came up when he searched for it.

The 8th pin is for the ground, otherwise they're pretty close to the same but, I'd go with the correct one. This may be helpful...

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