Replaced upper plenum with a chromed plenum. Had a vacuum leak between the plenum and TB. While determining the problem, the engine was running rough. Once the leak was detected and repaired, the engine continues to run rough.
Can detect a rich fuel mix. Has the ECU attempted to correct for the vacuum leak by running rich? Has the timing changed. How do I correct the mixture/timing?

 

Try the full ECU reset by disconnecting battery, pumping brakes etc

 

Tried that. Disconnected battery. Also went thru the reset steps.

 

Perhaps you continue to have a leak or another issue yet undiscovered? The ECU is running rich for a reason. Keep investigating and let us know how it turns out.

 

rub one out on the intake manifold....sometimes that works for me. lol

let us know.

 

I'm thinking that it evolves around the TB. The butterfly valve may have been touched and moved. According to Motordyne, the symptons would appear the same as a vacuum leak. I've tried the technosquare throttle reset procedure, but its possible that it didn't take. I'll have to retry.

 

BTW, took the car to the dealer today. Asked for an Ecu reset. He immediately asked if any mods were done, such as CAI. It has a popcharger on it. He proceeded to give me the "voided my warranty" speech. At that point, I took the car and left. I could tell they didn't want to get involved.

 

OK my brutha's (and a few sista's) problem solved. I had my team (my son and his friend) swap plugs for me on Sunday. Well those youngins put the six on the four, and the four on the six (coil packs) which was obviously causeing my problem. I've been away from the wrenching scene a little too long, because I should have been able to pick this up after it was buttoned up.

Well anyway, a lesson learned for those guys. Must pay attention to detail.

But I'm back and it feels good to have the power back. Thanks for your input, guys.

 

Wait a sec, could you please explain a little more in detail? Maybe I'm stupid or something, but I can't figure out what you're talking about exactly.

 

^ had firing order wrong....

 

Exactly!

 

So, nothing to do with a vacuum leak. Instead, you remembered other work that was done recently (plug change) that actually caused the issues (wrong firing order).

 

Nice recap! ?