Where does ECU look when cranking engine?

smracing · Post by **smracing** » Mon Mar 12, 2007 8:46 pm

When cranking engine does the ECU have its own start up map or does it work directly off the main fuel table? I am having an issue with the hot start with bigger injectors.

Should I be using the cranking fuel trim or should I be working with the areas of the map where start up goes?

Post by **Spunkster** » Tue Mar 13, 2007 10:23 am

make changes first to the overall fuel trim, and then start makign changes to your cranking fuel trim. THe last place you want to make changes is the fuel table to fine tune everything.

smracing · Post by **smracing** » Tue Mar 13, 2007 8:11 pm

Everything else is right, thats why I am hesitant to use the overall trim.

When I start the car it cranks on the first turn and then dies and I have to crank and crank and crank to get it to start again. Everything else fine mechanically.

92hb_hb · Post by **92hb_hb** » Thu Mar 22, 2007 12:10 pm

I'd like to know too.. My car runs real lean for about a minute and has also died out sometimes when I start the eninge after its been off for 10-30 minutes.. my WB shows AFR's in the neighborhood of 17-19..

In the morning when I go start it up, the AFR's are fine and this problem is non existant.. Also, when I"m driving and idling, the AFR's are normal too.. Its just during a warm/hot start will this problem come up.

Any ideas?

Post by **Spunkster** » Thu Mar 22, 2007 3:06 pm

Are you both using DSM injectors?

92hb_hb · Post by **92hb_hb** » Thu Mar 22, 2007 6:24 pm

nope..

GENUINE RC 750 Injectors..

I never had this problem when i was running s200

Post by **Spunkster** » Fri Mar 23, 2007 9:15 am

I woulsd suggest looking at your ECT and IAt compensations...the ECT would be the more important one.

92hb_hb · Post by **92hb_hb** » Fri Mar 23, 2007 12:14 pm

i will look over the ECT values..

Also..

I"m experiencing another very odd event..

I recentl switched from a chipped p06 to a chipped p28 for my s300 and when I run closed loop with the p28, the engine goes real lean.. I actually have to run it in open loop to get it to idle and read normal AFR's..

The PO6 did not have this problem when switching from open to closed.. Nothing else changed in the settings, other than the ecus..

Post by **Spunkster** » Fri Mar 23, 2007 12:47 pm

The only problem could be the ecu then. It may be damaged.