Hot start issue since going $0E, from $0D.

[96lt4c4]

Since I had to install a 4L80E, and changed over to $0E, I have developed a hot restart issue. I copied the main tables over from my last good $0D tune. Funny thing is I never really got my cold start issue fixed with the $0D tune, now I have just the opposite. With the 0E tune it starts fine cold, after it gets up to operating temp I can shut it off and it will start for a second, then die. It happens real fast. If I ever so slightly touch the gas pedal and try again it will fire right up. I have messed around with some stuff but nothing has seemed to help. The truck is MPFI with a vacuum referenced FPR. I may try removing the vacuum and seeing if it still does it.

[JeepsAndGuns]

It was my understanding that opening the throttle while cranking caused it to go into clear flood mode where it greatly reduces the amount of fuel it injects in. Do you think it might be flooding during hot restart?
What tables did you copy over from your last bin? Just spark and fuel, or did you copy the start parameters? I seem to remember seeing some hot restart parameters, you might try coping those if you haven't already.

[fastacton]

I believe that it only goes into clear flood mode at close to full throttle. On my test stand, I sometimes have to give a little throttle on the first start (since it doesn't know the IAC position, among other things) and I don't see any reduction in fuel. Maybe you need more IAC steps during cranking when hot?

[96lt4c4]

I played with it for hours last night and could not figure it out. Crank to run routines, Cranking fuel, IAC tables, and it seems to be something with temp. I can get it really hot, about 92*C and it starts and dies. If it cools off to 80*C, it will start. I can let it get hot, and burn my last good $0D tune and it fires right up. I cant find it. Unless there is a setting not populated in my XDF that is causing it. Before I came in from messing with it last night I started over with a stock 454 4L80E bin and changed the bare minimum, timing, VE, Injector, everything for PFI, and it fired right up. I did this as a test, but I may just keep going with it and start over.

And yes clear flood is holding it to the floor while cranking.

[fastacton]

Have you thought about trying a $31 bin and seeing if that would help? I'm just moved to $31 (from $42) and haven't had any hot start problems, but I'm still TBI.

[96lt4c4]

Have you thought about trying a $31 bin and seeing if that would help? I'm just moved to $31 (from $42) and haven't had any hot start problems, but I'm still TBI.

I have it fixed, I sat for hours going through both bins, $0E and $0D. The parameter that I think fixed it was "Number of counts to run Flag" $0E bin was 2, my old $0D bin was 6. Also "Number of DRP for Crank to run", was 0, old bin was 2. I changed those and did some idle VE tuning, and Crank BPW tuning. Truck starts great hot and cold now. Starts like a stock truck.

I ended up going back to my previous 5.7 $0E bin and ditching the 454 bin.

[fastacton]

I have it fixed, I sat for hours going through both bins, $0E and $0D. The parameter that I think fixed it was "Number of counts to run Flag" $0E bin was 2, my old $0D bin was 6. Also "Number of DRP for Crank to run", was 0, old bin was 2. I changed those and did some idle VE tuning, and Crank BPW tuning. Truck starts great hot and cold now. Starts like a stock truck.

I ended up going back to my previous 5.7 $0E bin and ditching the 454 bin.

Good info! I'm glad you figured it out. I'll have to remember this for future troubleshooting.