4.6 stroker in 00' xj need help with pcm tuning and misfire

[bandofthHawk]

hello,
just registered here on jeep strokers
very glad to see theres a website where technical information pertaining to aftermarket jeep motors can be had.
so heres whats going on:

got a 2000 Cherokee XJ its got a 4.6L stroker. The previous owner had it built back in 2010. (got about 25k on motor) It runs great, really pulls hard. the only ongoing issues ive had is every 2 months or so it throws a code for cylinder 4 misfire. I am in no way an engine expert but I don't feel like it actually is misfiring...but again im new at complex engine mods...heres all the information about the stroker I have.

00' xj block bored.30 over
4.2 crank
4.2 rods
Comp xtreme 4x4 cam duration 250/258
Lift. 462/.485 hydraulic flat tappet cam
Crower camsaver lifters
Keith black silvolite pistons
62mm tb
24# injectors
Banks header
Ported head (older style head) not 0331
Im not an engine expert by any means but i looked online and the comp website says the cam i have is "NOT FOR FUEL INJECTED ENGINES" so im questionable about why the previous owner used that.
My tb is brand new
New tps
New spark plugs NGK V-power
New coil pack
New exhaust manifold gasket
New catalytic converters
Again motor seems to run great...is it just that my pcm doesn't like the cam? I know I was told by the previous owner it was never tuned but that a flash wasn't necessary. he told me back in 2010 no one was capable of tuning the pcm. also I have been told I might need the aid of a Chrysler DRBiii tool...(I do not trust the stealership at all where I live...very shady) Let me know what u guys think
also I could use some tips on kickdown cable adjustment for my AW4. when I adjust the cable so I can get full WOT on my throttle body I get a slow clunky first -2nd gear shift...when I reduce the cable length restricting the WOT postion I get a nice smooth quick 1st-2nd shift but I cant get over 3500-4000k... the AW4 was completely rebuilt by Previous owner as well...again I am interested in the possibility of re programming for optimal engine running and tranny shifting. any help, tips, guidance will be much appreciated.

[Cheromaniac]

I am interested in the possibility of re programming for optimal engine running and tranny shifting. any help, tips, guidance will be much appreciated.

Hopefully FlyinRyan will chime in 'cause he's the man who can help you out. Alternatively send him a PM.

[SilverXJ]

Im not an engine expert by any means but i looked online and the comp website says the cam i have is "NOT FOR FUEL INJECTED ENGINES" so im questionable about why the previous owner used that.

comp cam doesn't know what the hell they are talking about, once again.

is it just that my pcm doesn't like the cam?

nope

When does the misfire happen exactly? Have you tried moving the #4 injector to a different cylinder and see if the misfire moves with it?

also I could use some tips on kickdown cable adjustment for my AW4.

Press button on cable at TB and holw. Pull TV cable away from throttle pedal. release button and floor gas pedal (with engine off)

re programming for optimal engine running and tranny shifting. any help, tips, guidance will be much appreciated.

Can't reprogram the shift point son the AW$. Most that can be done is torque control removal.

[bandofthHawk]

Alright thanks for the tips. I will try moving the injector around. As far as the misfire i dont feel it misfire, but again i might not have the experience with jeep motors to be able to tell. Also i have heard that the 00-01 computers in xjs are especially picky ? Do i need a custom pcm tune? As for kick down cable adjustment i should be able to achieve WOTand shift smoothly right? Is the aw4 capable of handling all the low end power of the stroker? Like i said i can smooth out the 1st-2nd shift but then i cant get the TB all the way open....why is that?

[SilverXJ]

While a tune wouldn't hurt, you don't need a custom tune, it won't help your misfire issue. You have problem. What is your AFR like?

What do you mean you can't get the TB open all the way if you adjust the TV cable? There is only one position for it to be adjusted to.

[bandofthHawk]

How do i determine my Air fuel ratio? As for the cable the way i was told to adjust it is press the button to release cable then open the TB all the way and release. Basically when i allow for 100% open throttle i get a late clunky shift from 1-2....when i push the black square adjustment piece away from the tb it restricts my maximum throttle position ...but gives me a much quicker smoother shift from 1-2

[SilverXJ]

You use a a wideband air fuel ratio gauge to determine your AFR.

The method you were told maybe be wrong, depending on when the the button is held. Push and hold the button, pull the cable housing away from the throttle body and let go of the button. The cable should be all the way out out of the adjuster. With ending off press accelerator pedal to the floor and you will hear several clicks. You will need more force to put the pedal to the floor as you need to over come the ratcheting mechanism.

[bandofthHawk]

Thankyou good sir. Will address that cable with surgical precision. As far as my engine parts list whats your opinion about it? Is it pushing the pcm out of whack? Would you say its a decent build?

[SilverXJ]

Everything looks fine. What is the part number on the plugs and the injectors? As far as the PCM it won't have a problem with that build unless your AFR is out of wack.

[bandofthHawk]

Injectors are ford i believe. Number on them are 4L8E-A4A should be 24 lb . Will get spark plug # when i get home. Thanks for the help man. Really appreciate it.

[SilverXJ]

Those injectors work out to around 27# on the 49 psi rail. Might be a bit large, but a wideband will tell you for sure.

[bandofthHawk]

Ill see about that AFR. any other injectors you recommend for my setup? So mine are really 27lb? Am i running rich most likely? My mpg does suck...but i do have 4.10 gears and 32s...

[bandofthHawk]

Spark plugs are ngk v power. The box says zfr5n stock no. 3459

[FlyinRyan]

I am interested in the possibility of re programming for optimal engine running and tranny shifting. any help, tips, guidance will be much appreciated.

Hopefully FlyinRyan will chime in 'cause he's the man who can help you out. Alternatively send him a PM.

Please no PM's, between calls, texts, emails, and being on multiple websites PMs are the least preferred method of contact.

Comp cams says "not for computer controlled engines" mainly for 1) the OBD1 guys and 2) the OBDII guys that are still living in the stone age and try to tune via manipulating map voltage.

A cylinder specific misfire- happening repeatedly, is likely not tune related.

A tune ABSOLUTELY helps these trucks.

[bandofthHawk]

Alrighty the method for the kickdown cable really helped. Thanks again. Whenever i have time this week i will thoroughly inspect the injectors. Ryan thanks for the info about tuning. So how does that. Work exactly? Do i buy a hanheld obd2 tuner and you write a tune file based off my engine parts list? Do you sell tuners?