Throttle popping from one cylinder why do the gods mock me so?

Why do the truck gods mock me so? I've got a 93 chevy 1500 350 5.7 tbi. I got a used engine, not rebuilt but used. This is the third engine the truck has had. Wife has a lead foot, but more on that later. Started the engine, sounded strong, oil pressure jumped up to 30 psi as soon as it started.

Check engine light came on. Then popping through throttle body. Read alot about timing. Adjusting the timing to TDC as specified in the Chilton's manual. Popping still heard in the throttle. New plugs, new wires. With the engine running, I removed then replaced the wires from the distributor. When I got to number five and removed the number five wire from the dizzy, the throttle backfire stopped completely. I have little to no power when I try to drive the truck and my oil pressure dropped back down to danger zone after I let it idle for about 10 minutes. Should I whip out my compression gauge or should I whip out my baseball bat and try to get the money back from the guy that sold me the crap engine?

Any advice would be great.

Brian

1993 Chevy 1500 "My Daddy gave me that there truck"
Reply to
brianwrites
Loading thread data ...

"brianwrites" wrote in news:1169525611.435794.115090 @v45g2000cwv.googlegroups.com:

as already mentioned in the only reply that wasnt lame.........sounds like a cam lobe not lobeing anymore.....if you remove the valve cover from the offending bank and turn it over with starter (ign. coil disabled) you will be able to see lack of lift on offending valve.......BTW: WTF is a 'dizzy'?

Reply to
KjunRaven

I figured dizzy was the distributor. As to the popping there is another possibility here. Used engine sat how long? There could be an intake valve stuck partially open Have run into that a time or two before with used engines that have been sitting for sometime. Pull the valve cover off the left bank, number five cylinder is third back on that side, the intake valve will be the third from the rear of the head. watch its movement, look for its valve spring to be partially compressed, also look for a broken valve spring. If it appears to be a stuck valve, pull the plug, bring that piston to top dead center, fill the cylinder with marvel, soak the valve stem with marvel mystery oil, let sit over night. with the plug out, turn the engine over to blow marvel out of cylinder and see if the valve freed up. if it didn't, Pull rocker arm off, and lightly rap the valve stem with a small hammer. Make sure you hit the stem square or you could dislodge the valve spring keepers

Of more concern is the low oil pressure. that sounds like worn main bearings.

Whitelightning

Reply to
Whitelightning

So, I pulled the valve cover and the rocker for the # 7 cylinder was completely loose and I'm positive that I adjusted it properly before installation. The push rod for the # 7 exhaust valve is completely loose even after tightening the valve all the down until it bottoms out. This sort of leads me to believe that the lobe is collapses. But I also look into the lifter valley and could see the the lifter doesn't seem to be sitting at a proper height compared to the others.

On another notes. I adjusted the timing and after each adjustment, the next time I start it, it jumps time. Is the ECM gone? Or perhaps a bad ignition moudule.

Did a compression test and everything checked out fine.

Reply to
brianwrites

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.