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PCM Tuning 1999 4.0 liter WJ

16K views 11 replies 10 participants last post by  Jasonhaha42 
#1 ·
I have installed a rebuilt 4.0 liter in 1999 WJ 4X4. Motor built with a Comp Cam, ported head and intake manifold, Ford 24 lb injectors. I have tried a hypertech chip with little improvement. Engine idles great. Accelerates smooth just not much much stronger than stock motor with 145,000 miles. Based on sootie tailpipe, motor is running rich or maybe retarded. When I first ran new motor, the engine light came on and the codes that came up where O2 sensors, throttle position sensor, and idle air control. I disconnected and shorted out battery cables and that cleared codes. Have a cold air intake and MagnaFlo catback with an aftermarket cat. I installed 2 new O2 sensors. Several places said I need to have PCM reflashed but I have not found anyone who can? Help!! I am in the Dallas/FW area. I have not replaced the stock exhaust manifold with a header yet. Does moving the cam position sensor have the same effect on the timing as moving a distributor did on the older motors?
 
#3 ·
well first off welcome to the garage :)

I am in the metroplex also !!!

you might want to check with Air Ram vendor here if they have a flashpaq also one of my friends he works at a firestone full service center on camp wisdom road he might be able to help flash ur system, pretty good mechanic the only one I trust out here ... and he can custom tune it

PM me if you need more details
 
#11 ·
SCT is available for the 4.0 crowd. I sold my first tuner to a guy with a 4.6 stroker motor in a WJ. I referred him to Josh Bryant. I spoke with the buyer several months later, and he said his experience with Josh was nothing short of excellent. I can also recommend Sean Powell, as I have experience with both tuners. Josh is no longer the tuner for Air Ram but the new guy, Chris, is pretty smart with this stuff. I would strongly recommend going the SCT route over "mail-order flash" tuners.

Does it still throw codes or have they not come back? You should, before seeking tuning, verify that there isn't an actual sensor issue or some other mechanical shortcoming like a vacuum leak.
 
#12 ·
Go tuners will tune all except 2002 I know this because I have hp for my left vehicles and wanted to tune the Jeep but mine is an 2002 so if anyone knows how I can tune it I’m all ears I’ve done the exact same thing to mine port polish intake and exhaust with components cam and 24 psi injectors idles rich. I can data log with how just can’t tune.
 
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