i have a problem guys, everytime i unhook my battery for some reason my car misses like crazy when cold but after a few days its fine.

For example i had to disconnect my batter a few days ago to put the new HIDs in, after i connected it again the car misses alot. Basically it starts right up but you can hear it idle at lower rpms, sounds like its gettin ready to stall out and before it warms up it misses when you give it some gas and sometimes its like it backfires, but at WOT its ok it seems.

This is something that started happening afteri put the new prom in. My setup is as follows, 89 trans am, 350 w/ flat tops, mild cam, 24# injectors, modified LT1 intake, MAF and my prom was programmed by Brian @ tpichips.com, i'm assuming my ecm is a '165.

Could it be that the table on the prom for open loop mode is not right so when i unhook the battery its like it clears any code or problem but after driving it for a while it fixes the problem by itself??

Its not something that will make me sell the car, its just that its annoying when i unhook the battery to do something that it will miss like crazy when its cold.
thanks in advance

 

any ideas??

 

You've got the basic idea, when the ECM is re-powered it resets the internal learned VE corrections.

The fact that it runs poorly after being reset is likely showing that the current tuning is off. The only way to find out is to get a data logging/tuning setup for the ECM so you can see what's going on and make corrections.

Paul T.

 

awsome, thanks for the reply, i already have WINALDL all i need to datalog would be the ALDL cable.