Hesitation on Tip-In

[Lynn D. Brown]

Hey Guys,

I have a little hesitation when I try to ease into the throttle from an idle or cruise, particularly when cold. I generally have to give it a fair amount of gas to keep it from sputtering a bit. Fully modded car w Precision 5 disc Vigilante TC. Lo-Imp modded ECM w 55 #ers.

Any Ideas ?

Lynn Brown

 

[strikeeagle]

Have you tried increasing minimum air slightly?

strike

 

[buickpower]

my maf sensor caused an off idle hesitation, switched to an Lt1 unit and it cured it right up. The bad sensor read 7-8 gps at idle, the lt1 brought it down to 4 or 5. I think that what happened was since the airflow reading was high the computer added a bit too much fuel at idle. then when you hit it, it had to get rid of the excess before it would respond. Might not be your problem though, because this didn't happen when cruising, just off idle.

 

[Raymond Bunch]

Tps?

 

[ijames]

I've always had my best luck with the settings Tom Chou recommended on the old Thrasher chips. With the engine warmed up and in OD, set the min air screw to give about 10-15 iac counts, and the idle tps to 0.40-0.44 V. You will have to reset the tps after you set the min air screw, and after you change the screw turn the engine off for 8-10 seconds to allow the ecm to park the iac to and reset. Should wind up with about 20-25 iac counts in park at idle. If the iac gets too high at idle it will cause a tipin stumble.

 

[GNational86]

How old are the injectors. I had a customers car we tryed everything to eliminate the tip in. We cleaned the injectors and it was gone.

 

[VadersV6]

Try slightly advancing the cam sensor. Theoretically, this should not do anything, but it absolutely has a big impact on tip in stumble with my car. No idea why. If I barely retard the cam sensor, I get a big off idle stumble in drive.