Truck not running so good need some help

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02-12-2008, 10:31 PM
americanthunder

Truck not running so good need some help

Hey guys i have a whipple running 12 psi and i just finished hooking up my intercooler. My truck is Nelson tuned, and i have a t56 swap done. The truck seems to have a hard time going back to idle when i push the clutch in and come to a stop.. the rpms seem to float, and when the go back down to 1000 sometimes they will go down so much the truck will stall. It seems to me like there is a problem with the mass air flow sensor. Its at the beginning of my intake and the air has to travel a long ways to the intake manifold. My other thought is possibly something with the whipple by pass valve maybe the engine cant get the air. Any one have any experience with intercoolers and mass air flow sensors? Do i possibly need to move it somewhere else. Or maybe its just the tune?? :cowl: im kinda stumped i called Allen and im waiting to hear back from him, any ideas?? any help would be much appreciated. O i just also thought the tune is fresh, i've been driving it for two days now and it seems to be getting alittle better like the pcm is learning the airflow, but it still doesn't seem close to being right, just thought id throw that out there maybe i just need to drive it more.. just thinking out loud! anyways any ideas please
02-12-2008, 10:36 PM
RedHeartbeat

You really need to get a speed density tune. Try unplugging your MAF and see if it still surges and gives you problems. Don't drive it too long like that, only long enough to determine if its the MAF giving you problems.
02-12-2008, 10:53 PM
americanthunder

Do you need a dyno to do a speed density tune? and what is it exactly
02-12-2008, 11:02 PM
Sleaper

A speed density tune uses a 2 bar map sensor instead of a MAF sensor. It allows you to tune based on manifold boost pressure. Basically, it has to be done live and allows the tuner to dial in more accurately than tuning through the MAF. At a certain point(varies depending upon mods), your MAF runs out of table/range and the tuner must "guess" how much fuel to add. It can be done just not as accurate. And no you do not need a dyno, just a lot of normal/aggressive driving.
02-13-2008, 09:44 AM
GMCwantsLS1

If you can move the MAF to right before the throttlebody that would more than likely fix your problem. Or SD tune.
02-13-2008, 10:13 AM
americanthunder

thanks for the help everyone ill mess around with the mass air flow later on today and ill see what i can come up with, also i want to move my temp sensor on the boosted side of my supercharger but i know its not gonna stay where i put it 12 psi will pop it out like nothing any ideas on that?
02-13-2008, 10:23 AM
GMCwantsLS1

Quote:

Originally Posted by americanthunder

thanks for the help everyone ill mess around with the mass air flow later on today and ill see what i can come up with, also i want to move my temp sensor on the boosted side of my supercharger but i know its not gonna stay where i put it 12 psi will pop it out like nothing any ideas on that?

I've never heard of one popping out, mine fits so tight you just about have to hammer it in the hole. Maybe you can glue it in if it does pop out. The grommet should fit tight in the pipe and on the sensor.
02-13-2008, 11:02 AM
americanthunder

I dunno there is alot! of pressure maybe i can fashion some sort of nut on the inside to hold it in place. i dont feel like i would trust it
02-13-2008, 12:09 PM
2k5Squirrel

Quote:

Originally Posted by GMCwantsLS1

I've never heard of one popping out, mine fits so tight you just about have to hammer it in the hole. Maybe you can glue it in if it does pop out.

:spit:
02-13-2008, 07:03 PM
americanthunder

i talked to Allen today and he told me i need to move my MAF somewhere in between the outlet of the intercooler and the motor, im gonna hook it up tommorrow and hopefully that will fix my problem! ill keep it posted