Hello,

I had my truck in the garage for a few weeks while I wrestled with fixing a cracked oil/coolant manifold, fun job. While I had it up I decided to do some mods. The following is what I added:

1. Factory Tech valve body
2. Accufab throttle body
3. C&L intake pipe
4. SCT big air 90mm MAF
5. Motoblue oil seperator
6. Diablosport Predator tune for 90mm MAF and 91 octane.

After the addition of the FTVB, TB, MAF and tune, I started the truck and it ran fine in park but ran terrible, stumbled, bogged down, seemed to miss while in gear. The TPS was set correctly (.993v).

I took everything but the FTVB off, put the stock tune back in and the truck ran better but still died from time to time while at idle and in gear, especially reverse, i.e. foot on brake, shift to reverse, engine dies unless I give it gas with the other foot, or while in drive I stop quickly from speed and the engine stumbles and dies.

I cleaned and then replaced the IAC, this seemed to help, but did not correct the problem, only reduced it.

I checked all the vac lines and everything seems to be connected properly.

I then replaced the fuel filter and added the oil seperator, I thought that my excessive oil in the intake could be part of the problem. I did notice that I'm getting lots of oil coming out of the small vac line from the boost bypass actuator, very evident in the new clean C&L pipe.

Does anybody have any ideas as to what the problem may be or what I should try next?

Besides the current idle problem, is there a compatablity issue between the diablosport tune and the SCT MAF, both diablosport and SCT tech lines have not been helpful. I tried the SCT with both the stock and Accufab TBs with equally poor results.

Thanks,
James

 

With the accufab throttle body there should be a idle adjustment screw you can turn in to make it idle at the right RPM. If you had the battery disconnected it might just take a few miles of driving to relearn idle adaptation. However the fact that you were having problems with it stumbling and hesitating while driving really makes me think you have a vacuum leak somewhere, or a vacuum line crossed.

 

my L did that to me one day after i cleaned the intercooler. after i checked over everything i reached down and tugged on the connector for the MAF snd it came off. it didnt click into place the first time i put it on. hope that helps

 

I've got the factory TB on the truck now and it's still dying in reverse idle. I just changed the plugs, and even though they need it, it didn't fix the problem.

I'll check the MAF again, I've had it on and off 5-6 times and maybe I'm not pushing it in all the way.

Thanks for the input.