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Discussion Starter #1 (Edited)
Driving to work and noticed once I got on the highway I was having trouble getting up to 60. So I drop it in 3rd and as soon as I dump the clutch the engine cuts out like I hit the rev limiter or governor. Back to 4th to dog it out, not enough power for 5th and I’m late for work. 5 miles later it starts cutting out like it’s out of gas, so I’m forced to put it on the shoulder. I had run it out of gas 3 times the day before trying to get to a station, so I was pretty confident I had burned up my pump.

Well after the pump and many other things it’s still running very rough at idle, smooths out decent around 2500rpm with a cutout every second or two, but building rpm past that takes very smooth and slow depression of the throttle, and it will never go over 4K regardless. If you try to blip the throttle or go WOT it just falls on its face in a fuel rich condition. I have a scanner that reads and maps live data, so I’m not in the dark, but all readings from sensors look normal less mapping a poorly running engine. My LTFT is -7 so it does recognize the rich condition.

Being that my only TDC was a P0300 random misfire I ended up “strategically shotgunning” pretty much anything involved with combustion, even though my scanner told me most of it was ok already.

-fuel pump (~40psi running)
-fuel filter
-fuel pressure regulator (responds to vac appropriately)
-injectors (redneck bench tested and cleaned two different used sets, also tested signal and power to injectors. Rail pressure holds for several minuets)
-compression tested twice (no throttle 182psi-185psi, and WOT 211psi-215psi. Both were dry test at 195 degrees)
-spark plugs and wires
-coils (then tested by cranking with plug wires removed- big sparks!)
-ignition control module (used untested)
-cam position sensor (tested good, and replaced)
-crank position sensor (tested (it runs))
-mapsensor (then tested with vac pump)
-idle air control valve (plus cleaned throttle body)
-TPS (tested, smooth)
-IAT (tested)
-ECM (swapped in and paired untested, perfect match part number)

Something I found interesting is that the shutoff perfectly corresponds with my Short Term Fuel Trim hitting 0% when building from a negative value during acceleration. Is it normal for STFT to not go positive?

Also this is a factory non EGR engine, but the intake gasket still has a port for the EGR, and I can’t pull vacuum on that port which would cause a tiny vacuum leak from wherever that port goes to now that the EGR isn’t there. I would assume I could pull vacuum on this sense it has a block off plate. Or is this some sort of “drip fed” non regulated EGR setup?!

Sorry for the novel, but Iv obviously been through a lot, and I’m out of direction!
 

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Discussion Starter #3
Checked the cat lately?


BTW...moved to 2.2 4bangin'
Well I checked the engine end of the cat, and it was intact, but because I welded the rear connection I couldn’t look through it. So I just left it off to make sure it wasn't causing the issue.
 

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All 98+ intake manifold gaskets are the same, and none of them have EGR ports. The EGR port is blocked off on 99+ intake manifolds, it the round part molded into the top just after the throttle body.
 

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Discussion Starter #5
All 98+ intake manifold gaskets are the same, and none of them have EGR ports. The EGR port is blocked off on 99+ intake manifolds, it the round part molded into the top just after the throttle body.
As long as all the gaskets are same I guess that’s what matters. Thanks for the affirmation!
 

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Discussion Starter #6
My neighbor suggested I check the timing chain. Sure enough the timing tensioner imploded and it progressively jumped 3 teeth. I can’t believe there’s enough sway in parameters to keep it running! Also the fact that it didn’t throw anything about crank position or cam position is frustrating..
 

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When you change the timing set, make sure to also replace and clean out behind the little orifice plug that oils the chain. If it's plugged, you'll be doing this job again.
 

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Discussion Starter #8
When you change the timing set, make sure to also replace and clean out behind the little orifice plug that oils the chain. If it's plugged, you'll be doing this job again.
Right on! I just pulled it, and sure enough it was plugged. I’m picking up the timing kit today and it comes with a new one. I read somewhere GM updated that galley port, hopefully that’s what the kit comes with. It’s the Cloyes tensioner delete set. <one less thing
 

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You should send that right back where you got it from. That set is garbage. Only use factory timing parts or you're going to hate yourself. Also, the galley plug can be purchased very cheaply at the dealer. gmpartsdirect.com and similar dealer parts sites have good deals on factory parts.
 

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Discussion Starter #10
Honestly I wouldn’t have considered going aftermarket on a deep part until I saw the engineering of GMs tensioner. I love my GMs, but I think I’d rather roll the dice on aftermarket than put in a part that looks like it should come with a choking hazard warning.
 

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Alright, you've been warned. I've personally ran the Cloyes tensionerless set, I hope you like a nice rattle in your engine.
 

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Discussion Starter #12
New timing set installed. Iv got my doubts about running without a tensioner, but the truck already has 175k. Changed the oil and filter a couple times to make sure it was debris free. Let it warm up once and the radiator cracked. It looked like it had been a long time coming. So replaced the radiator and I’m finally back on the road.

Thanks for the help!
 

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Discussion Starter #13
Alright, you've been warned. I've personally ran the Cloyes tensionerless set, I hope you like a nice rattle in your engine.
It’s not horrible but I see what you mean. I guess I can look forward to it really start singing when that chain loosens up a bit.
 

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It’s not horrible but I see what you mean. I guess I can look forward to it really start singing when that chain loosens up a bit.
There was an extended discussion on the topic here:

 
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