Adding fuel

[truckermike5]

Hey all, pretty new to the tuning jsyk. I recently put a stock engine back in my 02 Silverado. Couple issues I'm having are very high idle on start up, like 16 to 1700. Idle will slowly come down to about 1000 but wont come down to 750 until the engine temp is around 130. The truck still has headers full dual exhaust and cold air intake. I'm guessing these are causing the idle issue. I had a tuner look at my tune and he said it adding fuel across the board and to add 8 to 10 percent. Can't get in touch with him anymore so my question here is where or what scale do I add the fuel. Any help would be much appreciated. Thanks.

[2xLS1]

I had a tuner look at my tune and he said it adding fuel across the board and to add 8 to 10 percent.

Fuel doesn't control idle speed. Air does. Either through the throttle body, through the IAC, or a leak past it.

[truckermike5]

I appreciate your answer but the tuner that told me to add fuel definitely knows what he's talking about and would have told me it's an IAC issue. The ecm is adding fuel across the board and was told to add at least 8 percent. I'm guessing the CAI, headers and dual exhaust are causing it to run lean therefore ecm is adding fuel. Just need to know where to add the fuel. What I've been reading on various forums, and I may have misunderstood, adding fuel involves VE and PE tables as well as timing. Just too involved for my tuning knowledge. I'd post the tune file but I don't see an attachment icon here. Forgot to mention I have a P0332 DTC, low voltage, bank 2 knock sensor. Don't know if this is related or separate issue.

[Haulinbass02]

You are basically telling the ECM there is more air and to add fuel. VE AND MAF tables. It isn?t as simple as just adding it in. You can just flat add in 8% across the board but that would be the wrong way about it. If it is beyond your tuning knowledge then you need to get someone to tune it for you. Don?t want to risk hurting the motor by not doing something right.

[village_idiot]

Post a log and tune file. Go to advanced post and look for the paper clip icon to add an attachment. You can add fuel via the MAF or the VE tables. The PE (power enrichment) table dictates what the target AFR is during higher load/rpm situations. Get an idle log that is at full operating temp, and a normal driving log and post them

[truckermike5]

Post a log and tune file. Go to advanced post and look for the paper clip icon to add an attachment. You can add fuel via the MAF or the VE tables. The PE (power enrichment) table dictates what the target AFR is during higher load/rpm situations. Get an idle log that is at full operating temp, and a normal driving log and post them

Thanks for your replies, I attached a log file and the tune file. Another memory lapse...forgot to mention, cats hollowed out and downstream O2 mil disabled. Thanks again everyone.

[village_idiot]

Does this truck have a stock camshaft? Why the 750 commanded idle?

[5FDP]

Base running airflow seems really high too. Just saying.

[kevin87turbot]

The tune is pretty rough looking. It's certainly been tuned for an aftermarket cam. It's got a knock sensor code as well. It will need to be addressed.

[truckermike5]

Thats just where it idled the best with the previous cammed engine.

[truckermike5]

The tune is pretty rough looking. It's certainly been tuned for an aftermarket cam. It's got a knock sensor code as well. It will need to be addressed.

Ya I'm aware of the knock sensor code, but wasn't sure if that is caused by the lean condition or a separate issue but I have new knock sensors. I'll have to double check the tune but I thought it was the original stock tune I downloaded before I installed the cammed engine. Maybe the easiest thing to do is find a stock tune and write that in. Thanks for your reply.