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Travis, Chevy Technician
Category: Chevy
Satisfied Customers: 980
Experience:  7+ years of GM dealership experience, GM ASEP trained, Assoc. Degree in Auto. Tech.
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1996 chevy: tk 1500 4x4..5.7 vortex..rebuilt engine..full tank of gas

Customer Question

I have a 1996 chevy tk 1500 4x4. The engine is a 5.7 vortex, my question is in reference to valve adjustment on a newly rebuilt engine. The truck sat for over 2 years with a full tank of gas. It smells pretty bad but i have added fuel treatment and octain boost, just for added info on the truck. I get some small backfire on trying to start the truck and it sounds like it wants to start but just wont! The plugs wet and smell of bad gas. could this be the problem or could the valves be to tight ? They were adjusted with the engine on the stand, 0 valve lash and then 1/2 turn. This thing is driving me nuts! Can you help? Thanks Mike
Submitted: 7 years ago.
Category: Chevy
Expert:  Travis replied 7 years ago.

Thanks for the question.


Usually the valves don't need to be adjusted on this engine since it uses hydro. lifters. But if it is needed, you would tighten the nut till there was no lash, then turn 1 full turn. As well there is a specific order of doing it as well.


However, 2 years of sitting, I would definely start with putting in fresh fuel. Adding octain boost and a treatment would not be enough to off-set an entire tank of bad fuel. Start by getting new gas and clean the plugs with some brake/carb cleaner and we'll go from there.

Customer: replied 7 years ago.
I know the valves are hydro, and i know they are adjustable. What about the back fire in the intake? would the bad gas cause the wet plugs and the backfire? could valve adjustment cause both on a new engine.
Expert:  Travis replied 7 years ago.

Since you adjusted, did you run the engine prior to parking it for 2 years?


Bad gas can still "burn" in the form of pre-detenation or actually being ignited correctly, but still may not run right. Wet plugs is definetly a sign that the fuel is not igniting properly. Now, the valves could play a role in this, but it the lash was set properly prior to parking, then I don't feel that they would come loose just sitting there. There is one other thing you can try. Pull the fuel pump fuse or relay and try starting it using carb/intake cleaner. Of course it would only run as long as you are spraying enough in the intake to keep it running, but it if does run off that, then the fuel will be the issue.

Customer: replied 7 years ago.
The valve lash was set when the engine was rebuilt. Again this is a newly rebuilt engine. The timing has been rechecked several times to ensure its right, although the instructions from gm are not as clear as they need to be. The dist was placed in and aligned with the oil pump, when I reset on the comp, stroke the rotor is on #1 cyl. I take it that your opion is the valve adj is not an issue and this is all due to bad gas not to tight or loose valves? The truck wants to crank but wont. Again new Engine the last one spun a rod. Every thing is new including the radiator because of the oil cooler, metal powder and shavings found everywhere inside. This engine has not run since replaced.
Expert:  Travis replied 7 years ago.
That being said, since the engine was never ran after it was replaced, it could be something more then just fuel. I don't feel the valves will be the issue though. If the distributer was installed 1 tooth off, it could cause this same issue. The best way to start checking this out would be to try and run it off an aresol cleaner. If it still will not run that way, then we would need to look into other issues.
Customer: replied 7 years ago.
I have tried everything but aresol can or starting fluid. Nothing to loose but 30 bucks at this point. Can i contact you again if that doesnt work? running out of money.
Expert:  Travis replied 7 years ago.

Yeah, start with that and see what happens.

You do not need to pay until we get this working, unless you want to. Otherwise, I'll just leave this post open until you return and let me know what happened then we will go from there.

Customer: replied 7 years ago.
That will work. I dont know where you are but its 11:42 in charlotte n.c. and my wife would kill me if i tried this tonight. I will check back with you monday night, thanks.
Expert:  Travis replied 7 years ago.

I'm on the east coast too (Atlanta) , so just let me know tomorrow, I should be here.




Customer: replied 7 years ago.
Sorry for the delay in getting back to you. So far nothing has worked. Im going to try resetting the dist. and checking the fuel preasure at the rail. You didn't mention fuel preasure. I had to figure out how to disable the fuel pump. The fuse and relay didn't work because the oil preasure switch came into play. I'll let you know what i find.
Expert:  Travis replied 7 years ago.
I didn't mention fuel pressure yet because I was waiting to see what happened when you sprayed the carb cleaner into the intake and tried starting it that way. Please let me know what you find on the fuel pressure and what happenes after you reset the dist.
Customer: replied 7 years ago.
Have not had a chance to get back to the truck yet,easter weekend. I'll get back to you soon.