Hi All, I recently purchased a 2001 gmc Sonoma 2.2 with 210,000 mi on the odometer. The previous owner stated that the motor was rebuilt " I dont know if it was a full build or just the heads or if it truly even was" it is a cranks but doesn't start. I tested compression on all four cylinders and it is from firewall towards radiator 160/155/(under 100)150 I also checked for good spark and I do have it. I went through fuses, previous owner said he parked it and it just didnt start so replaced the fuel pump. It still didnt start so he replaced the steering wheel ignition wiring. Honestly I do not know very much about mechanic work but I do know air, fuel, spark and as of now I have those. The only thing I can figure is bad gas? But that doesn't make sense because when I sprayed brake cleaner directly into the throttle body it still wouldn't start. Any thoughts anyone?
He's giving you a bunch of bologna if that one is under 100 lb since the engine was not rebuilt at all or was incorrectly rebuilt
Unfortunately I agree, finding a good mechanic/shop here in Phoenix Az there are few and far between. It gets tiring when you spend money just to switch out parts and it doesn't change the result.
Rebuilt...that's a load of rubbish with that one cylinder under 100 psi. Just because he said it was doesn't mean it was done or done correctly. Also did you confirm the firing order is correct? Distributor rotates counter-clockwise and should be 1-3-4-2
Would that one cylinder under 100lb stop a full start for the engine?
Yes, If by "Distributor" you are meaning the "coils/square boxes" where the spark plug wires feed into on the passenger side of truck. The spark plug wires were reversed on 1-4. Once switched the back firing stopped and a smooth crank continued.
Soo, where do I go from here? Is the whole thing toast or? BTW I paid 3hundred over two years ago for it, but it took me over 1.5yrs to actually get it because of the plandemic.
I'd be surprised if it started with brake cleaner. You want to use starting fluid instead. Anyway, one low cylinder shouldn't keep it from starting, but it can depending on situation inside. If it does fire up it'll run like crap. If you believe it was rebuilt by previous owner, then it's been apart to some degree and could not have been put back together correctly. Also mentioned the fuel pump was replace by him. Do you hear the fuel pump get energized when you initially turn the key? Is there gas getting to the engine? Should see about 51 psi with key off, about 60+/- key on.
I found this discussion in the S10 forum. There's a tech service bulletin mentioned and other things others have experienced with the Chevy S10/Gmc Sonoma
https://chevroletforum.com/forum/s-10-blazer-20/cranks-but-wont-start-12146/
It sounds on the verge of starting but will not fully start. Initially there was backfiring until the wires were switched at the coils.
Fuel pump is energized and I have good pressure.
I have been through that forum, I understand it will run poorly but I am still trying to find out "why" it will not run. Trust me for the 300 I paid as a project I am not totally disheartened. I truly want to learn basics when working on a vehicle, after watching Scotty for the past year I figured I could practice as he taught. The tires alone were worth the purchase to me, it just baffles me because I KNOW it SHOULD start but it isn't.
My bet is whatever the previous owner is the reason for the problems. Good video if you wanted to back-track the previous ignition switch replacement.
https://www.youtube.com/watch?v=TXKp3UEXnUQ
🙂 yes, he seems like a trustworthy man up there in NY. I did learn a lot on how to test from watching his videos which really did help get me this far. Thanks for taking the time to reply.