Starts fine then floods and dies... - Third Generation F-Body Message Boards

EagleMark · 10-26-2008, 10:06 PM

Having a problem with cold start on a 440 Mopar engine with 1227747 ECM AZFT chip and an old Holley TBI with 1:1 simultaneous four barrel.

I have chip burning and data logging experience but this one is quite the challenge.

Problem is it will start right up then flood and die. If I lower the fuel pressure from 13.5 to about 9-10 I can get it to start and run but of course all data shows way lean.

I attribute this to low vacuum readings. The motor reads a steady 12 inches of vacuum when warmed up at idle of 750 rpm, while my stock 90 Blazer or 90 Suburban read 19 inches of vacuum. We are about 2500 feet elevation.

I've read the How to fix some of those common idle issues (big cam, surging, stalls, etc.) but mostly for MAF and I didn't understand it. This cam is also no were near that big.

I have TunerCat and TunerPro but can't find or don't understand a setting for MAP sensor. I thought if I could change some MAP settings it would clear up this problem?

EagleMark · 10-27-2008, 05:29 AM

Well I've done several hours of searching and reading here and seems the cam (low vacuum idle) seems to cause this. Stock VE table for idle is 31.3 and data logged is 57.3. So I increased just a few cells in the main VE table around the idle and will give it a try tomorrow.

All other VE cells were very close to the data logged so I left them alone.

EagleMark · 10-27-2008, 06:32 PM

Have to wait for the batterey to charge before I can give it a try.

Here's the changes I made to the main VE table, only the 57.0 numbers around idle as that is what data shows. Am I heading the right direction?

EagleMark · 10-27-2008, 11:05 PM

Well that sucked! Won't even start now, I forgot to add VE2 and I think I went the wrong way...?