Poor Idling

**katoom** · 06-14-2007, 01:27 PM

I bought my truck new, 6.0L , installed cold air, headers, exhaust, hypertech, thermostat, MAF, truck ran great, now I seem to be having some trouble keeping it running when I lift off the gas and come to stop it wants to die and does if I dont double foot the brake and gas. I swapped the MAF back to factory, no help, when I first start the truck run around 1000, then it warms and drops to 600, if I rev it and take my foot off the gas it will drop to 2 or 300, and then a second or two later recover to 4 or 5 hundred....any ideas???

**dr_ws6_00** · 06-14-2007, 01:59 PM

might be your throttle position sensor. does the service engine light come on

**katoom** · 06-14-2007, 03:00 PM

It hasnt for awhile... it used to come after I would fill up with gas..but I was thinking that might be do to evap system... Is there a way to check it??

**dr_ws6_00** · 06-14-2007, 05:46 PM

not really sure on a definite way to check it, see if one of your buddies will let you swap off his, (same year, make, model, engine) see if that changes anything. cant get a donor car buy one and put it in, if it doesnt change anything take it back. take it and have it scanned if the service engine light comes on, think auto zone does it free, but i dont know if the hypertech will mess with any of their readings. did you remove the cats? o2 sensors still connected? also check to make sure you have a good seal around your cold air, if you suck air in after the maf it can make it run really weird too. another thing to check could be your pvc valve. just pull it off and shake it, if it rattles its good. if its quiet replace it. check the hose attached to the pvc valve too it might be clogged. if none of the above dont change anything man im all out of ideas for now.

**dr_ws6_00** · 06-14-2007, 05:54 PM

not really sure on a definite way to check it, see if one of your buddies will let you swap off his, (same year, make, model, engine) see if that changes anything. cant get a donor car buy one and put it in, if it doesnt change anything take it back. take it and have it scanned if the service engine light comes on, think auto zone does it free, but i dont know if the hypertech will mess with any of their readings. did you remove the cats? o2 sensors still connected? also check to make sure you have a good seal around your cold air, if you suck air in after the maf it can make it run really weird too. another thing to check could be your pvc valve. just pull it off and shake it, if it rattles its good. if its quiet replace it. check the hose attached to the pvc valve too it might be clogged. if none of the above dont change anything man im all out of ideas for now.

**Naf** · 06-15-2007, 12:14 AM

Ah, i have had this problem in the past, The engines idle control needs to be cleaned...Since you have a new series vehicle the idle is controlled by the throttlebody. So better take it off and insure all wholes are clear, and open.

Additionally your intake might need a good Cleanin...I learnt that using those handheld programmers just dump more fuel and that then causes more carbon to build up in the intake.

Have fun with that...

If you are lookin to score a few more MPG and low end torque, add in a good set of groundin wires...

**SeVeReDiStOrTiOn** · 06-16-2007, 07:25 AM

If I was you the first thing i'd do is remove the throttle body and clean it good....along with the IAC valve like Naf said. Does the hypercrap have a live data monitoring feature? If it does you can use that to make sure your TPS is working correctly, if not then replace it....they're not adjustable like the older TPS's so don't worry about that.

Also i'd keep the stock MAF on....aftermarket MAF's make it harder to get a good tune and they don't do anything that you can't do through a tune anyway. I'd sell it and the hypercrap....if you like handhelds get a diablosport predator but for tuning software hptuners is the best. The predator is around the same price as the hypertech but does so much more it's not even funny.

Doesn't your hypertech read/erase codes? If it doesn't just go to autozone and you can use their scanner for free. Man that thing is such a POS...I can't believe they get away with selling it for the same price as the predator.

**Naf** · 06-27-2007, 01:44 AM

WHATs the news? You get it runin right?

**02BURBAN** · 07-26-2007, 12:38 PM

I Had A Smiular Problem With 2002 Suburban..
I Change The Map Sensor, Plug And Still Did The Same Thing...
I Took It To A Shop And The Only Thing They Came Up With Is The A/c Was Dripping Water From Condensation On The Bank2 O2sensor...
I Was Cleaned And Put A Loop On The Wire That Connect To The O2 Sensor....
Hope This Helps...

**Cruel-X** · 08-09-2007, 08:45 PM

I had this EXACT SAME problem. All i did was Remove teh TB and Clean it. When u do Make shure u Manually MOVE the fin inside and get where it sits there with be a black ring of crap i Garentee, Also reach inside ur inake n clean that as much as possable, I did this and it was cured if it dont cure it mabe it spreed to ur injectors??

**LS1formulafreak** · 08-09-2007, 10:28 PM

what solvent did you use to clean it with?

**LS1formulafreak** · 08-09-2007, 10:29 PM

oh and i just today cleaned the MAS tiny sensor wires with rubbing alcohol today. could be my imagination but it seemed to run much smoother...but prolly just delusions of graduer

**Naf** · 08-10-2007, 04:33 AM

I use throttlebody cleaner and afterwards WD-40...It cuts the carbon...

Just dont freak when you wanna start and it takes a while to do so...Also give the intake tube a squirt and the MAF a GENTLE cleanin...