What is needed to tune a stroker

[96xjstroker5]

I have a 96 xj with a 4.7 stroker. I do not know what I need to tune it right now it doesn’t idle and runs overall pretty bad but in the higher rpms it runs ok. Any help/tips to get it running good

Thank you

[Cheromaniac]

What are the build specs of your stroker, and which injectors are you using?
You'll probably need to plumb a wide band O2 sensor into your exhaust to see what's happening with the air:fuel ratios.

[96xjstroker5]

It’s got 27lb injectors. It’s bored .60 over and stroked
Would the wide band o2 sensor just tell me what to tune. What else do I need to adjust the fuel ratio?

[mpgMike]

From what I've gathered reading through threads on this Forum and others, you are in luck! The OBD II Jeeps are now serviced by HP Tuner and a few other vendors. Tuning can be as simple as paying the price of admission, then taking all the time you need to get it where you want it. Just be thankful you don't have an OBD I '95 or older ECU, as there does not seem to be turn-key tuning solutions for them. The WB O2 is extremely valuable for tuning WOT and other Open Loop conditions, as the factory NB cannot see far from either side of 14.7:1.

On another note, there are MAP-Adjusters and a couple other add-on tuners some folks have had luck with. You can also swap injectors around to find a good compromise. Don't discount an adjustable fuel pressure regulator; maybe even one that adjusts fuel pressure based on engine vacuum. Be aware if you want to experiment with the MAP-Adjust that when you alter Baro & MAP values, you not only change AFR targets, but also ignition timing. Good luck!

[Brianj5600]

What he said. HPT will allow you to tune problem areas with timing and fuel. Using map adjuster and fuel pressure is less precise moving the entire scale. Timing is very conservative under load. This is a stock 04 TJ timing table and my modified table.

stocktiming.png

Modified for my stock motor. Stroker coming this winter.

ACT2.1.png

I have added a few degrees at WOT in the last column at 3008 rpm.

[Cummins90]

Tuning the obd1 jeep was a pain but now you just convert to obd2. X2 on the AFR gauge, it will help you now and in the future if issues arise.

[96xjstroker5]

Thank you for all the helpful information. What plug and play program options are good?

[TJBUD]

I’m starting the same process with my 98 4.7 wrangler described on the basics thread. I bought the AEM 30-4110 WB O2 sensor and gauge. I’ll watch this thread for your progress and post when I make progress. TJBUD

[mpgMike]

A bunch of guys on this and the Jeep Enthusiasts Forums swear by Flyin' Ryan. I do my own, but he does remote tuning (he's out of Texas). If you get overwhelmed and wanna ask for help, apparently he is the premier specialist for Mopar ECU tuning.

https://frptuning.com

[Cam Hensley]

What are the build specs of your stroker, and which injectors are you using?
You'll probably need to plumb a wide band O2 sensor into your exhaust to see what's happening with the air:fuel ratios.

Where would you plumb in the wide band 02 in the exhaust line?

[TJBUD]

Cam, I installed the AEM 30-4110 WB sensor with gauge. You can download the instructions from the aem site. They say install 18” downstream of the nearest exhaust port, >10deg above horizontal, before the cat. On my 98 TJ this is 4” downstream of the factory pre-cat narrow band sensor. The gauge tells you early in break-in if you are close or way off too lean (risk damage) or too rich. And, if at constant throttle, speed and load it converges near 14.68 you know that’s closed loop operation. If it won’t converge, the pcm is running open loop. Then when you’re ready to tune, the sensor has additional outputs to connect to the tuning solution for data logging.
TJBUD

[Cam Hensley]

Cam, I installed the AEM 30-4110 WB sensor with gauge. You can download the instructions from the aem site. They say install 18” downstream of the nearest exhaust port, >10deg above horizontal, before the cat. On my 98 TJ this is 4” downstream of the factory pre-cat narrow band sensor. The gauge tells you early in break-in if you are close or way off too lean (risk damage) or too rich. And, if at constant throttle, speed and load it converges near 14.68 you know that’s closed loop operation. If it won’t converge, the pcm is running open loop. Then when you’re ready to tune, the sensor has additional outputs to connect to the tuning solution for data logging.
TJBUD

Nice, thanks for the info TJBUD- Adding this to my notes

[DiegoR]

What he said. HPT will allow you to tune problem areas with timing and fuel. Using map adjuster and fuel pressure is less precise moving the entire scale. Timing is very conservative under load. This is a stock 04 TJ timing table and my modified table.

stocktiming.png

Modified for my stock motor. Stroker coming this winter.

ACT2.1.png

I have added a few degrees at WOT in the last column at 3008 rpm.

I do have HPT too, but I'm not a tuner and what I do mostly in newer Jeeps is pay for custom online tuning and be done. Sure I can adjust some "preference" parameters and top speed, delete some sensors to prevent a MIL, etc. But not involved exactly in tuning or at least I can slightly change some values.

I read these JETC are very limited (no wonder why are so old) but I do plan to play a little bit with spark advance a fuel tables with my stock 4.0L, while I build my stroker in a spare engine and as well develop the bracket for the S/C I'm going to install in my 4.0L first, and once is somewhat dialed or fully tuned, then swap the 4.6L stroker and dial again the fuel/tming maps.

I can't install a 2 BAR map sensor and do the conversion so it can read negative-0-positive pressure (if that phrase makes sense) as I don't believe the JTEC can hanadle that (we tried that with a 4.7L WJ, installed a 2 BAR map sensor, tried to scale it the MAP but it wouldn't see "any boost" whatsoever, so my friend who has a dyno and some experiencie with HP, dialed it and ran very good, but said, the PCM essentially was running as a N.A. engine just tweaked the parameters.

I pretend to add a Innvoate dual gauge sensor (AFR-BOOST) and add these analog outputs for the HPT logs, this will at least "help" in some way to fine tune the map when is boosted.

I think the sace of the maps for fuel/timing in these JTEC can't be changed? Or is possible to change them?