I need help with idling issues

baggett3_27

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Hey guys, I have a 99 GT with a V2 E-trim that is idling erratically. The A/F is very rich until I begin to raise RPM's, then it leans out and bogs down. After the quick bog down it clears up and A/F is fine, but only seems to clear up over 2000 rpm. I can't even get steady datalogs because the idle is so bad. I do have the SCT PRP, but even the adjustments I've made to the tunes aren't helping. Any help would be appriciated due to me being in England, and the tuning help I have been getting has been via email.
 

Black*Death

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Hey guys, I have a 99 GT with a V2 E-trim that is idling erratically. The A/F is very rich until I begin to raise RPM's, then it leans out and bogs down. After the quick bog down it clears up and A/F is fine, but only seems to clear up over 2000 rpm. I can't even get steady datalogs because the idle is so bad. I do have the SCT PRP, but even the adjustments I've made to the tunes aren't helping. Any help would be appriciated due to me being in England, and the tuning help I have been getting has been via email.

What changes have you made. I am by no means a tuner, but may help others with what to suggest.

Some common issues with idling problems include a dirty MAF, IAC, or TPS issue. Bad O2 sensors?

Also, there is a tuning section at SVTP. Might get some feedback by posting your question there?
 

crazycarlo

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also other mods, what size injectors, MAF type and size, type of TB.....the more info u can give and specifics the more it will help others.
 

01yellercobra

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Are you running a draw through or blow through MAF? If running a draw through is your bypass recirculating the air? I sounds like your MAF transfer isn't tuned correctly. Until that's dialed in it'll seem like nothing will help. I had to pull 20% fuel just to get my car to start. So I understand the frustration.
 

baggett3_27

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I'm running a non I/C draw through 90 LMAF, 39lb injectors, C&L plenum w/ 75mm Accufab TB, SLP exhaust, and an AFM PP. I've pulled fuel from my MAF xfer, and neutral ISC valve. How can I test my bypass valve to see if it is recirculating? All sensors are clean and near to new.
 

01yellercobra

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You don't pull fuel from your ISC. That's just a duty cycle. Concentrate on getting your MAF transfer dialed in. If that's not correct nothing will work right. You will have to adjust your manifold volume die to your MAF being further from the throttle body. But that will show up in your tip in.

Your BPV should be connected on both sides. Mine is mounted to the discharge pipe just after the blower and I had a hose connected to the power pipe. Just make sure it isn't open and venting to atmosphere.

IMO, if you can do it, I would switch to a blow through set up. I had a draw through and hated it. I switched to blow through the car ran so much better.
 

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