moneypitGT

First off this is a new motor. 347 h/c/i and running 30 lb injectors with calibrated maf. the cam is comp part 35-518-8. The motor was dyno tuned and has a custom chip burned. Runs fine off idle with no problems.
The problem i am having is the car idles rough when cold and will not stay running at all when hot. The iac is new as are the o2 sensors and tps Have done a base idle reset several times. Was able to get the car to idle decent when cold at about 950 rpm but there is still some surge. From a cold start the car will idle for 10-15 mins like this until it gets up to normal operating temp. After that when i shut the car off and try to restart while still warm the car only runs for about 5-10 secs. idle will surge between 400-1500 and it will stall. it will stay running as long as i hit the gas and keep the idle above 1500. as soon as i let off the gas it will die. Have to wait until engine is cold again to get it running. Been playing with this for about a week now and any help would be appreciated

moneypitGT

Also I have checked and rechecked all of the vacuum lines and there is no leak, all the egr is deleted.

2011scgt

i would go back and get your money back for that chip. what is timing set at? did you set the tps at .98 volts? what MAF are you using as you may need to clock it.. are you running an egr?

moneypitGT

i had the timing set at 12 and havent checked it again since the tune. he told me that it needed a new iac which i replaced even though it was less than a year old. the egr is deleted and the tps is at .97. i have not messed with the maf at all it is in the stock location but i can try that.

Venomantidote95

Did he know that your maf was calibrated before the tune?

rydinturbo

how old is the tfi module

Chrisopher Adams

this sounds very similiar to the problem im having with my 97 if you figure it out id like to know thanks

moneypitGT

yes he had all the info prior to the tune and i checked the tfi last night and wasnt crazy about the way it looked so i ordered a new one and will hopefully put it in today after work.

2011scgt

how did he know the iac was bad....it might be cabon'd up

moneypitGT

changed out the tfi and no difference. thought i would pull out the chip that he burned and see what happens. big surprise the car runs perfect. starts right up, idles smoothe and runs fine warm. just seems to be a little rough in the higher rpms now where it was nice and smoothe before. im gonna call this guy on monday and see what he has to say.