EFIDynoTuning Forum

Check voltage drop from compressor to battery ground with compressor running. It should be close to 0. check your grounds. compressor to engine block, engine block to frame. A bad ground can cause this with voltage backfeeding where ever it can.

41 is the cycling switch input. 86 is head pressure input. 69 is WOT cut out relay. PCM will not "run" your ac. It will cut the compressor clutch for excessive pressure, or WOT.

I did this a few years back.. Trying to find an old pic. I took a 28oz 95 Mustang balancer, chucked it up in my lathe. Turned a small spot on the back side, right after the crank seal surface ends. Then took the Explorer trigger wheel, turned a hub to mate it to the balancer, and pressed it together. Been working great for the last 5 years, 25k miles.

Jump the relay, drive it and see if it's good. If so, you know it is either the relay, or something on the control side.

What do you need? Torque specs? caps are 71-106 inlbs. Ford says to install cam/ torque it, then use a special tool to install followers after that. If you don't have the tool, tighten the caps slowly / evenly with followers installed.

I had a goofy issue with my 5.0ho and an sct tune. Got my base from Lasota Racing, and it would drop cylinders like torque management / trac control was kicking in somehow. It would do it at the damndest times. It seemed like a hardware/engine issue. Lucky for me, I had it running prior to that tune and never had that issue. It had to be something in that tune. I tracked it down to something with the rev limiter settings. I don't know exactly what, and Lasota basically told me I was nuts. It never did it again after I eliminated his rev limiter files though.

Ok. So I'm not crazy. I am finding SCT doesn't give me a lot of the parameters that I need for this. So, can I just go through your forum here and donate to have you straiten this stuff out? If I understand it correctly, I can send you my .mtf file, you can make the necessary changes on your end, and I can continue with my SCT stuff on my end where I left off? I am more than willing to do that if it will work. I really don't want to invest in / learn new tuning software at this point. Thanks!

I realize it’s not ideal, and I have figured out a way I may be able to add the tr sensor back as a pcm input. It’s just that, it doesn’t do this all the time, which makes me think I can program my way out of this. Maybe I’m wrong. A couple of possibly dumb questions; do you know what the FN85x functions are in SCT language? And what do you mean by the “low slope banging the injector clip? Lastly, how do I increase idle spark torque reserve? There are several titles having to do with torque calculation, I haven’t messed with any.
Iscdc is at 07 hot idle in park. That’s as low as she’ll go. I did kick the tc under down to 0. That may have helped a bit.
I did lower cranking pw at higher ect’s. Although, I don’t think that is part of my issue. It only goes rich on hot start after a stall from putting it into gear. Otherwise, it starts fine hot. It has to be learning something. Because if it goes into it’s rich funk, and I reflash the pcm, it’s instantly better…. Until another stalling (or 2) into gear. I hope I’m explaining this right…. Thank you for your input. The knowledge in your write ups is unbelievably helpful.

Good evening. Long time listener, first time caller. I have a 68 Mustang with a 96 Explorer driveline transplant. Cal/ strategy in subject line. SCT proracer, so I do all my own tuning. I am a master Ford tech of 20+ years, so I think I know my way around Ford driveability… anything Ford for that matter. I stroked it to a 347, Trickflow heads/ induction. FTI custom cam, 80lb Siemens Deka injectors, 99 GT Ford Maf… I’m sure I’m forgetting something. Anyway, I’ve had this car on the road for 4 years now. Never been on a dyno, but it goes like hell. Starts good, idles good, runs great. Thanks to the write ups here on dialing idle airflow, and all that. Idles @ 750 rpms nicely. Base fuel tables, cold, startup enrichment, decay, all set. Getting to the problem…. It will stall out when I put it in gear. When I go to restart, it surges. Runs rich and stalls. I have to get on the gas, stay on it, and bring it down slowly to idle again. My wideband will drop down to .95 lambda and back to 1 a few times, then it’s good… until next time. When it stalls at first, wideband will drop down below .85. If I tap the gas when I drop it in gear, it’s fine. If I don’t, and it stalls, I have to rev the piss out of her and play games for a couple minutes to get her to settle down.. all the while, looking like a jackass in the parking lot. I can’t figure out what is causing this. A couple things; I have the maf dialed in perfectly down to 200 counts. I can’t get it to idle any lower to set those numbers reliably. (I’m assuming they are close?) When I drop into gear, could my maf counts be dropping for a split second into those ranges and that “corrupts” my fuel trims? I have tried leaning out the range under 200 counts, it hasn’t made a difference. Second thing, I have a USshift stand alone trans controller. So I have trans control shut off in the PCM. There is an anticipator for IAC and trans engagement. That is not there now. I could see that possibly causing some stalls, but not the rich issue. I have been down my software a hundred times looking for some setting that I missed. I have been fighting this for a couple years, I’m sure I’m forgetting more info… I hate asking for help, but this thing has me stumped. Any help is GREATLY appreciated.
Thanks Brian