Hesitation/Stumble with Chipped ECU

[hotrodj]

Im trying to work on a map for my 90 EX 4 door, F22A. With F22a4 intake, no iabs.

I started with my old trusty chipped P28 ive had for years. I was messing around and it was running ok, then I think the prob started after i wrapped up the rpm to about 6k on a pull.

After that, it has had a weird hesitation or stumble right at 2k thru about 25,2600 at part throttle/cruise. After those rpms it runs great.

Ive tried adding and subtraction fuel and spark. Ive tried a dif chipped p28, and a p75. Ive also tried p28 and p30 base code. Ive got everything disabled currently but the eld. Ive tried enableing and disabling stuff like the baro sensor, eld, iacv, closed loop and whatever else.

The engine runs fine with the stock PT3 ecu.

Im stumped.

[MRX]

I battled a similar problem on the F22 for quite some time. It's the timing. You need to lower it more than you think you would need to in the partial load area. It starts around 15 in/hg and goes to about 5 in/hg. I'm not on my tuning laptop and can't open my f22 map at the moment but I think I remember it being somewhere around 28* of timing at the lowest point in those load and rpm areas (I'll check when I get home). It makes the map look really wonky but it'll drive like butter.

As for it starting after your 6k pull, i doubt it unless something mechanically loosened. Most likely you just managed to avoid the problem area beforehand and now you can't get away from it.

Edit:
This is one of my turbo maps but the ignition timing in the vac areas was the same for the n/a f22 mostly until 0-2 in/hg vac. Try copying these timing values as best you can and see if that works.

[hotrodj]

Well I finally got around to copying that map and trying it out. Just chipped a P06 the night before and used that ecu.

Same results as the P75 an 2 P28s.

Im stumped.

Only thing I can come up with is, being that my can is a 1990, the first obd1 year, that the ecu and wiring may somehow be part obd0 yet. The stock pt3 in my car still has the obd0 style led/sight glass for cel code reading. That is sole obd0 style component I see.

Getting very frustrating. Thanks for your help.

[WiKKeDV16]

Check your Tps calibration

[hotrodj]

Check your Tps calibration

Ty! I will check it out, but it is set at stock setting on Crome and works perfect with the stock pt3, so I figure its in my map somewhere. But I will hook up the volt meter and see what it looks like.

[WiKKeDV16]

Do you have Crome pro ?