Retro's 1989 GMC Sierra C1500 Sportside Indy clone

[yevgenievich]

I would definitely go through with locating tdc to verify. Reminds me when I have managed to get a bbc to run with wrong firing order and 180* out on the distributor. It ran poorly, but it did run.

 

[HotRodPC]

Oh geez, that firing musta been way out. I've never been able to get 180 out to run at all. Just burped out the carb and farted out the exhaust consistently and that's how I knew it was 180 out.

Yep I'd check that balancer too. IIRC, I used a piece of vac hose to know my #1 was right at TDC, then looked at the pointed and it was off by 1/3 of a turn and dizzy was pointing at #1. I had it timed by ear so I never knew it for the longest time til one day I decided to use a light and the mark wasn't even in the ballpark.

You said it was running real good a few days ago, and now this with no CEL? I sure hope you haven't had a cam lobe go flat for some reason. No rocker arm noise huh?

 

[RetroC10Sport]

No noise at all, just normal running noises.

Barely made it around the block, still running very poorly. Unhooked the MAF and it seemed to run better, can a MAF be bad without setting off the SES light?

 

[HotRodPC]

No noise at all, just normal running noises.

Barely made it around the block, still running very poorly. Unhooked the MAF and it seemed to run better, can a MAF be bad without setting off the SES light?

Anything is possible, but you'd certainly think as important as the MAF is to the ECM it would throw a code. Because there is not a SES light on, I think I'd be racking my brain on anything that can be wrong not associated with the ECM. Is it possible you got a bunk fuel pump? Broke some **** loose with the pump swap or ran low on fuel and suck up some **** off the bottom of the tank clogging a fuel filter? Or how about the old fuel filter not liking the new higher fuel pressure and it collapsed within itself clogging it up?

 

[RetroC10Sport]

I might try the fuel filter tomorrow. But the fuel pressure is okay. I haven't replaced the filter in a year though so it probably needs replaced.

This started after replacing the IAC...I had to take the TB off to do it. The gasket was okay, I replaced it today and no change. I put the old IAC back and no change. Infuriating.

 

[89Suburban]

And the brown wire for the ignition advance is plugged in right? You try reading a vacuum gauge on it? Good ideas to check TDC manually to confirm the dampener is correct or not.

 

[RetroC10Sport]

Replaced the fuel filter, no change. Just chugs when it is put in gear but idles fine in park. Pissing me off now.

 

[RetroC10Sport]

And the brown wire for the ignition advance is plugged in right? You try reading a vacuum gauge on it? Good ideas to check TDC manually to confirm the dampener is correct or not.

Yes, yes - vacuum is good at 16hg and the dampener is correct.

thirdgen is no help at all...

 

[89Suburban]

Replaced the fuel filter, no change. Just chugs when it is put in gear but idles fine in park. Pissing me off now.

Wish I was there to help.

 

[RetroC10Sport]

fuel pressure is 31 at the rail, it doesn't go down or up when it does it's ********. Unplugged the FPR and it stays at 31.

Bad gauge or bad FPR? Or bad new fuel pump?

I'm now more convinced it's fuel related than sensor related.

 

[89Suburban]

I feel so useless!!!!! :bangmyhead:

 

[yevgenievich]

Fpr should only change fuel pressure on change in load. Does scanning it show anything interesting?

 

[HotRodPC]

Just for ***** and giggles I'd pull codes to see if there are any stored. Not likely but something isn't right. I too would be leaning toward fuel problem since no codes.

 

[89Suburban]

How do the plugs look?

 

[RetroC10Sport]

I'm waiting on a part for my ALDL cable. No codes at all. Hoping it will be here this week.

I replaced the TB gaskets, both the top plate and IAC/coolant bypass plate. It's better but still chugs and pops through the intake between 1000-1750 RPMs. After 2000RPMs it goes like a rocket but I can't be taking off at 2000 RPMs all the time or have it idle at that.