drmaune

I am putting a 2012 5.3 into a 67 camaro and I am at the point of running the car. The car starts great but idles a little high around 1k, the bigger issue I have is when I press on the pedal the car hesitates a little then revs to 2000-3000 and never comes down, if I press it again it revs higher until I shut the car off and restart it that it goes back down to 1000 RMP idle. I have sprayed and sprayed for a vacuum leak but cannot find one, The fuel pressure at the rails is around 62. The MAP pressure is between 1.45 and 12 with the mean at 3. The MAF is over 8" away from the TB. The car throws no codes unless I unplug something so I know it is reading the sensors. I have added a CAM and replaced the truck intake with a pro comp and kept the 2012 TB which is DBW and I can hear/see if work. I did send the harness out to be reworked and they put a startup tune on it with the CAM specs. I read through some other postings on reluctor sprocket but I know mine is 58 tooth with the correct ECM. I spoke to another tuner and he believes it is the tune but I want to get some other opinions as to what I might be missing.

Thanks

Greg.H

The high idle and being stuck at 2000 rpm after revving sounds like a vacuum leak or possibly too much air getting into the system. Could the throttle be stuck open too far? What is the mixture at this rpm and at idle?

drmaune

The long term fule trim on bank 1 is 5.02 and 3.28 on bank 2. If it is a vacuum leak I sure cannot find it when I spray.

Lsxford

iTrader: (6)

The exact concern happens everytime after i clean sludge from these dbw throttle bodies. A simple 'idle/throttle body relearn' has always fixed them. I have the GM scan tools but i believe hptuners can do it aswell

drmaune

I tried that a few times but does not seem to change. I am thinking it is the tune cause I let it run longer last night and the headers were glowing but the engine temp was never over 210. From other reading is sounds like the timing in the tune is retard/advanced causing it to run lean and the excess fuel is burning off in the headers. I think once I get a full tune the issue will clear up, I did have a little more pedal response this time but the idle would never come all the way down to 700 as I am told it is tuned for.

If there is anything I am missing please let me know. -- Thanks