dieseling
my fitech runs super good, only issue I have is it diesels when shutting off the car. I have rpm at 850 and have 15hgi in idle. it does it in park and drive. I have electric fans, msd 6al, not sure if unit can get some sort of run on from these components?
Need a datalog of issue.
Check your voltage at the coil/distributor to see if it still exists after turning the engine "off". Otherwise it's spontaneous combustion due to high compression. Not too likely I'm thinking.
Any number of reasons, possibly one, but not necessarily any, of the following.
fuel octane not high enough
timing out
incorrect heat range plugs
hot spot from carbon buildup
I put a 1200 hp kit on BBC 540 with 9:1 comp, dosnt do it everytime but seems to do it more often with summer comming. Running on or dieseling,,
Once again, heat too much, timing too far advanced, power at the fitech white wire after engine shut off, carbon buildup, etc.
Had the same problem. Problem fixed by adjusting AFR at idle to 13.6. To lean AFR at idle seams to be the reason for dieseling.
383 CSB AFR 190 heads, 10:1 comp ratio. 270 Comp cam XE Hyd roller. Fitech 600 hp no power adder. Accel 300 plus ignition with MSD pro billet distributor. Long tube headders and Edelbrock performer intake. 4-speed manual trans.
Any resolution to this? I've got a similar problem, but I think I can rule out the ignition. It did it before, and I thought I had solved the problem when I hooked up the ignition control of the FiTech. But after a few days, it still does it. Prior to hooking up, I was running a vacuum advance dist with a HEI system, now I'm using a 6AL digital box with a Pro Billet distributor. Timing was set on the dyno, and the engine was rebuilt within a couple thousand miles....so I doubt it's carbon. Mild cam in a gen 6 GM 7.4. Just wondering where to go...it's occasional, like once in every 15 shutoffs...and I've not been able to identify a pattern in when it will do it, just wondering anyone has solved this issue yet and is keeping it a secret? I just updated my software and am trying to get the Pro-Cal software installed but I'm having trouble with the K-line driver and windows 10. Once I get it installed, I'll post a datalog. Looks like the only thing I can try at this point is lean out the idle AFR....