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Discussion Starter · #1 ·
89 Chevy Tahoe 4.3. 140k miles

Whats been replaced and/checked to be functional
Plugs, wires, distributor, cap, fuel pump and filter, the ECM was replaced with one from junkyard, map sensor, CTS, EGR, the entire tbi was replaced from junkyard, and timing was set with new distributor.

I have spark on all 6, injectors are spraying. No codes.
It will every now and again start with the help of starter and will idle until I turn it off but usually just cranks and usually won't even fire, but has never made it out of the driveway. the plugs are wet with gas, and a bit of oil when I pull them out. After letting it air out and cleaning the plugs, it will usually start up on the first try. Used an inline spark tester, to verify spark on all 6. So Its flooding I guess due to too much fuel being dumped by the injectors? Is this more likely a problem with a sensor or the fuel system itself? No visible leaks, havent been able to check fuel pressure.
I'm the third person to turn wrenches on this thing. It was my grandpa's truck he left me after he passed a few years ago. It means a lot to me and I want to get it running more than anything so any help is appreciated.
 

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2002 S10 2WD (4.3L, AT)
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You have a laundry list of used parts installed.....was this to fix the problem you're having now? Or were those parts installed to facilitate reliability and now you're having the problem?

Are you sure those used parts are valid for your vehicle? ....the ECM in particular? I am concerned your used ECM might be for a different vehicle or perhaps was tuned for different parameters than are now valid. You might try going back to the OEM ECM and see if that makes a difference.....
 

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Discussion Starter · #5 ·
You have a laundry list of used parts installed.....was this to fix the problem you're having now? Or were those parts installed to facilitate reliability and now you're having the problem?

Are you sure those used parts are valid for your vehicle? ....the ECM in particular? I am concerned your used ECM might be for a different vehicle or perhaps was tuned for different parameters than are now valid. You might try going back to the OEM ECM and see if that makes a difference.....
I tried switching the OEM prom to the new one and got a code 51, and no response when trying to crank it. With the new prom, I just get the normal code 12.
The old ECM fried from shorted wires the first guy who worked on butchered. Which Ive fixed, pulled the dash and checked all of it.
But I see your point, is there a way to verify if the ECM is compatible?
 

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Discussion Starter · #6 ·
Also a pretty big update, coolant and gas were in my oil pan. I've pulled the intake manifold off and I'm not sure if its leaking or the heads. I'd rather not pull the heads if I don't need too. Is there a good way to determine which is the problem and would that cause a consistent no start? Like not firing on any cylinders with spark and fuel?
Some other notes, the ports for the EGR were almost 100% blocked, and upon removing the intake manifold, the coolant channels are holding coolant, and I noticed a lot of oil around the front and back of where rtv or something failed. The intake gaskets look okay to me but I'm not really sure what I should look for. I don't think I see anywhere it would have been leaking, but I could be wrong. A little intimidated about pulling the heads lol
 

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2002 S10 2WD (4.3L, AT)
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You have gas and coolant in the oil and a blocked EGR. I would be concerned with more than simply getting it started. Recommend a rebuild of at least the intake manifold and head gaskets. If that's too big a job, then look to hire a pro or replace the motor with one in better condition. Just my thoughts. Keep us informed as to your ultimate solution....
 

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2003 Sonoma SLS ext. cab 4.3L / 4x4
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You have gas and coolant in the oil and a blocked EGR. I would be concerned with more than simply getting it started. Recommend a rebuild of at least the intake manifold and head gaskets. If that's too big a job, then look to hire a pro or replace the motor with one in better condition. Just my thoughts. Keep us informed as to your ultimate solution....
I concur. A more thorough tear down/ inspection is in order. The conditions you described are alone enough justification.
 

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Discussion Starter · #9 ·
I've gotten down to the heads right now. Weather is terrible on the south east. Need to get the power steering pump off and I'll be ready to pull the heads.
 

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Discussion Starter · #10 ·
There is a valve leak on cylinder 4. This is the passenger side. Anything I should take note of? Fyi I have already started removing the old gasket material from the block before these pictures were taken
 

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Discussion Starter · #12 ·
Been a while but finishing up re seating valves and final surface prep for the heads before it all goes back together. I don't suspect this will fix the problem I started with, but hopefully I won't have any new ones.
 
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