Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Hey guys and gals, i have a 1993 chevy K2500 that i swapped a 5.3 out of a 2002 Chevy Avalanche. I have lean ltft’s and the exhaust is popping usually from a dead stop. If i give it 1/2 to 3/4 throttle i can get it to clean out and run good. Also, it will start good in the morning, and after that it usually takes a little cranking before it starts. Its not consistent. I have been all over the intake with brake clean. Several times, i have disconnected the brake booster and plugged line, i have good fuel pressure, and my 02 sensors seem to be reading correctly. My air intake system is all sealed up as well. I have NO Codes. This is driving me crazy. Ive thrown the parts cannon at it as well, and gone back to the origional parts with no luck. The egr, and purge valve have been deleted. What advice can you recommend at this point? Thanks
A few questions to get a little more info -. How high are your trim numbers? Are both banks the same? Are the only high at idle and what do they do with some rpms held?
One bank is 18.5 the other is 12 and I have tried to raise the rpm and watch it and i cant remember what they do. I want to say that they do change a very small amount
I would definitely check to see what they do with some rpms. If they get closer to 0 you are looking for a vacuum leak and if they get worse, MAF or fuel delivery is likely.
Remember that V style engine can have an internal intake leak that you'll never find with a smoke test.
Yes, it was a good known engine. It drive fine when i first got the swap done. Im gonna look more into a possible fuel blockage. Ill report back if i find out the issue. Thanks for the information
