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99 k2500 7.4l runs horribly after tune up

Bdmlilburn

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Bdmlilburn New Member

Bdmlilburn

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1999 k2500 7.4l auto

Alright guys I'm a honda mechanic and I really don't know much about these Chevy trucks except that I love them. Bought her about a month ago decent condition needed some maintenance items. The engine idled perfect. Had a steering issue and a hard shift when hot. Brought her to work today. Changed the pitman arm and Idler arm and bracket to get rid of the free play in the steering. Changed the trans filter which fixed the shifting. Should have gone home after that. I had already purchased a tune up lit from rock auto so I figured what the he'll I'll throw it on. Installed new cap rotor wires and spark plugs. Ngk iridium spark plugs and the tune kit was united. Looked to be the same as the parts I pulled off.

Got her all back together and start her up and now I have a very rough idle. Huge loss of power as well. I'm kind a stumped. One thing I noticed is the distributor seems to have some free play in it. Don't know if that's normal on these or not. Checked all my connections and nothing is loose. No service engine light either. Seems like it's misfiring but without codes I need some Chevy guru help.

Also will add I noticed there was play when installing the rotor. Could I have missed an important aligning step and now I have bad ignition timing?

 

Probably going to be a week or so before I have a chance to tear it back down. I don't know much about the ignition timing in these things but I'm thinking the distributor moving when pushing the new wires on may have made it go out of time. or me shifting the plenum to get to that awfully placed cap bolt may have knocked something fuel related loose that sits under it. Not looking forward to having to break that egr pipe free. Someone email me some muscle

arcasey Enthusiast

arcasey

Posted
Posted

I don't know for certain on the 7.4L but I do know on the 5.7L's that the timing can be off slightly without showing a check engine light. I also remember on the distributor for the 5.7L there was a bolt and clamp piece that would lock the distributor in place after it was adjusted. Should be some play in the distributor for fine tuning the timing but there should be some sort of locking mechanism that locks it in place once the final tuning adjustments are made. Again, not sure on the 7.4L but on the 5.7L Vortecs (1996+) you couldn't tune with a timing light. You have to have one of the professional scan tools to read the timing and make adjustments. I think the parameter is cam retard position and should be set to 0 with the engine speed around 1000 RPM. There is a set procedure for tuning these engines.

 

"Give me a lever long enough and a fulcrum on which to place it, and I shall move the world." - Archimedes. Here's your muscle for getting that egr pipe free. If the wrench isn't long enough, extend the wrench, haha. A shot of some "Aerokroil" works wonders on stubborn bolts and nuts.

Colossus Senior Enthusiast

Colossus

Posted
Posted

Better off sticking to the AC/Delco plugs and wires for those years.

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