Optimal Timing Advance / Curve

[CobraMarty]

How do you get him to advance the timing to 35 degrees from 32?

[superstingray77]

Just asked him via e-mail. He said as many engines will detonate above 34-36 he sets 32 to play safe. So we hit it at 35 and its really happy. Verfied the change on my datalogger/scanner.

[CobraMarty]

What device are you using to make the timing change?

[superstingray77]

The entire program is being done by the SCT flashpack handheld. So what's been happening is he has been pulling the fuel in the wrong area, the fuel has been getting pulled from the area that controls the lightest of loads possible say cruising <60 with a tailwind and do not try even the slightest bit of acceleration or it dives into the 11.8-12.2 range and stays there. So not only is all acceleration pig rich and sluggish but if your cruising at 70+ or into a headwind the afr stays in the 12.2 range and kills mileage and power big time. I'm frustrated at the least out of 7 tunes only one is driveable and that's with a map adjuster pulling voltage set at 4.83v.

[superstingray77]

Update, so determined to solve this tuning issue I traced every vacuum line on the Jeep and found a wiped out line at the EVAP Emissions Pump behind the drivers headlight. The fitting faces straight down to the frame and is tough to see. Replaced that line since its one of the main ones connecting to the intake and VIOLA! the tune is actually working correctly now. Thing runs a TON better with the mixtures proper. My AE is still 12.2-12.3 but comes up to 12.8-13.1 when I lean on it just a tad more. Seems like a not linear spot in the tune but it runs great now.

[FlyinRyan]

I also am an SCT tuner and have tuned multiple strokers. The resolution of the JTEC PCM is somewhat limited (ypu are stuck with 7 columns of load, however they can be rescaled). I can tune the full range of the PCM, meaning I can manipulate closed loop AFR as well as open loop AFR of course. I can also do part throttle enrichment. PM me if you have any questions.

[superstingray77]

In case anyone missed my other thread.... FlyinRyan is legit, this truck flat out hauls azz and drives as perfect as a stock truck.

[Cheromaniac]

I also am an SCT tuner and have tuned multiple strokers. The resolution of the JTEC PCM is somewhat limited (ypu are stuck with 7 columns of load, however they can be rescaled). I can tune the full range of the PCM, meaning I can manipulate closed loop AFR as well as open loop AFR of course. I can also do part throttle enrichment. PM me if you have any questions.

Can you do anything with the SBEC PCM that came on 91-'95 models?

[FlyinRyan]

I also am an SCT tuner and have tuned multiple strokers. The resolution of the JTEC PCM is somewhat limited (ypu are stuck with 7 columns of load, however they can be rescaled). I can tune the full range of the PCM, meaning I can manipulate closed loop AFR as well as open loop AFR of course. I can also do part throttle enrichment. PM me if you have any questions.

Can you do anything with the SBEC PCM that came on 91-'95 models?

Sorry but no can do, Dino. Convert to a OBDII harness and then we'll talk.