Cyl misfire issues? or so it says...

[rwkhaussupply]

I redid my engine with a clearwater head, mopar cam, 30lb injectors, and 62mm TB. I was running RC12LYC, then moved down to the NGK next steep cooler plug due to very white tips and getting a P0300, p0301 & p0305 codes. I have a map adjuster set to get about a 12.1 at WOT with the above.

I have replaced the cap, rotor, plugs, turned the map adjuster on/off, and still the same codes. I get them after about 30 miles of driving. I dont drive it much, and still trying to get all but one monitor to go off so I can smok it and finish the registration that is out right now. But I cant due to getting the codes before monitors go off/out.

I was thinking it was maybe to much load with the 4.10 gear and 35" tires. I just recently swapped the 3sp auto to a AW4 4 speed (last month) and yesterday swapped the 4.10 gear to a 4.88. Drives so much nicer. Had a pretty intense vibration under load and in a high gear, that went significatly away. Thinking it was related to the gear/load/and much more solid mounts everywhere with the AW4 swap and exh routing.

Now after driving it last night and this morning, the same codes popped back up. Idea's?
I am thinking:
My lifter preload was about 1.5turn. could that be effecting it with the comp ratio I am at = Dyn 8.68:1, Statis 9.73:1. maybe its holding open to late or something, IDK...
My injectors for those 2 cyl are somehow malfunctioning or too much fuel, and mixed with comp ratio, putting out the spark enough to throw code?
I have read that maybe CPS is interfering and causing code?

I just am ready now to smog and get tags... It is 1000 times better driving today then last year and want to enjoy it...

[jeepxj3]

I think that the 30lb injectors are too big and I would try a set of Bosch 703 injectors. And I would take the MAP adjuster off. Stock recommended plugs should be fine. I wouldn't go colder set. Make sure the plug gap is 0.028"-0.032".

[rwkhaussupply]

I think that the 30lb injectors are too big and I would try a set of Bosch 703 injectors. And I would take the MAP adjuster off. Stock recommended plugs should be fine. I wouldn't go colder set. Make sure the plug gap is 0.028"-0.032".

IDK..
If I turn off the map adjuster and it like its not there. But WOT suffers on the wideband A/F.

30lb seemed to be about right when I had the other cam and head, now maybe a tad to big by theory, but on a calc, they are what injector company's recommend size wise. I do have 0280155917 23lbs I will swap in and read A/F...

The colder plug ran more disireable in the A/F also and smoother it felt, and I got from NGK site:
With modified engines (those engines that have increased their compression) more heat is a by-product of the added power that normally comes with increased compression. In short, select one heat range colder for every 75-100 hp you add, or when you significantly raise compression.
So, I think I will stay with the one step colder.

The rec plug gap is .035 factory right? I did read making the gap slightly smaller with OE coil/voltage, and raised comp might be good. After I get it smogged I am going MSD so I can open them up to .040-.045. But need the codes to stop. I will reduce gap.

Thank you for your post

[Cheromaniac]

Here's my take on your situation:

1. Those 30lb injectors are way too big. You need the Bosch 0280155703 (rated 22.7lb/hr @ 43.5psi, flow 24.1lb/hr in your 49psi fuel system).
2. If you downsize the injectors you may not need the MAP adjuster.
3. With a DCR of 8.68:1 you'll need to be running 93 octane fuel if you're close to sea level.
4. A lifter preload of 1.5 turns (0.090") is too high. I recommend that you add 0.030" shims under the rocker arm bridges (Crane 99179-1).
5. Check the upstream O2 sensor and make sure it's functioning correctly.

I'm confident that if you follow the measures I've recommended, your engine will run another 1000 times better.

[rwkhaussupply]

Here's my take on your situation:

1. Those 30lb injectors are way too big. You need the Bosch 0280155703 (rated 22.7lb/hr @ 43.5psi, flow 24.1lb/hr in your 49psi fuel system).
2. If you downsize the injectors you may not need the MAP adjuster.
3. With a DCR of 8.68:1 you'll need to be running 93 octane fuel if you're close to sea level.
4. A lifter preload of 1.5 turns (0.090") is too high. I recommend that you add 0.030" shims under the rocker arm bridges (Crane 99179-1).
5. Check the upstream O2 sensor and make sure it's functioning correctly.

I'm confident that if you follow the measures I've recommended, your engine will run another 1000 times better.

I will swap out the inj after work today and see if I get codes still. But can you explain how going to a smaller injector will fatten up my WOT more? And so why/how can I remove the MAP adj and get lower A/F reading?

I am running 91... It shows no signs of ping, and many say even on a 89 I might be ok. SO I put the best typical pump gas here in cali.

Yeah I dont know if I am ready to do the valves again, thats a PITA job with the spacer on there and no room for the T-stat spacer, as well as a steel valve cover and the Huge ass hold dn bolt holes, getting the cover aligned while tightening, correctly centered.

the O2 reads fine on the torque screen, just like my stock engine did pretty much.

Will swap injectors, close gap up a tad on plugs and see what I get.

Thank you for your help.

[jeepxj3]

I wouldn't worry about WOT now being rich or lean, you just want no codes so you can get all the monitors on so you can register the thing. NO WOT until it's registered.

[rwkhaussupply]

Well today at lunch I went over to the jeep and looked again. I have my 19lbs 0280156024 five0 "blue Knight" Injectors in it currently. I thought I last tried the larger 30lbs ones.

SO with that being known I have some 0280155832 25lbs at 49psi 4 hole, I will swap in and regap slightly smaller. It was getting plenty of fuel at WOT. SO this might allow the Map adj to be switched off.