Jeep Strokers

First post here on the forum. I have a 4.6 stroker AW4 in my 2000 XJ that is missing at idle. I have played with timing and AFR and can’t get it to go away. The build consist of:

Russ’s 0.30 over 14cc pistons and rods
4.2 4CW Crank
Custom Cam 228/232 512/544 112LSA installed at 108ICL
-0.01 Deck Clearance
0.043 head gasket
Ported Tupy Head
Ported Intake
24lb injectors, 49psi fuel pressure, 320lph pump
0.600 lift valve springs
ZFR6F-11 Plugs

Static compression ratio of 10.69:1, dynamic of 8.6:1, and with altitude included 8.46:1. I’m running 93 octane. No pinging or any other issues. Timing on plugs looks perfect, fuel looks perfect. All tuned in open loop. Throttle blade has been opened slightly per reading Flyin Ryan’s post on his site.

I also have a set of RC9YC plugs and NGK ZFR7F-11 plugs to try. Grounds have been checked, all sensors are good.

The engine also surges when coming to a stop, 5mph and slower. If someone could help me with tuning that out.
Any advice is welcome.

You could try cleaning the idle air control valve that's inside the little barrel on the side of the throttle body.

You can't adjust the timing by turning the distributor. The timing is adjusted by the computer. Turning the Distibutor affects the injector timing. I'd start with the injector timing. You're going to need a snap-on scanner or dealer drb to adjust it.

You said, "All tuned in open loop." What are you doing for tuning?

Being an XJ, you should have a distributor. An obvious question is how are your tune-up parts -- specifically cap, rotor, and wires? Could you possibly have a cracked ignition coil?

"The engine also surges when coming to a stop, 5mph and slower. If someone could help me with tuning that out.
Any advice is welcome."
I had the same problem with mt 5.9 magnum transplant (same JTEC computer). A tuning shop or I couldn't tune the idle surge or dying when coming to a stop. My idle would die down and sometimes stall as soon as the computer saw wheel speed. My tj is a 5 speed.
Contact Chris Jensen. He was able to fix my tune. You can contact him at [email protected]. He knows his stuff especially when it comes to older Dodge/Jeep. He's been tuning Vipers for decades and is well known in the Viper world. His prices are more reasonable than Ryan. I can't say enough good about Chris. Tell him David Gray said hi.
What are your cam specs?

Never mind, I see the specs in your post. Thats a pretty big cam and with 112 lobe centers, it might be a bear to tune.

dwg86 wrote: ↑February 28th, 2025, 8:52 am You can't adjust the timing by turning the distributor. The timing is adjusted by the computer. Turning the Distibutor affects the injector timing. I'd start with the injector timing. You're going to need a snap-on scanner or dealer drb to adjust it.

Injector timing is spot on at 0

Cheromaniac wrote: ↑February 27th, 2025, 10:58 pm You could try cleaning the idle air control valve that's inside the little barrel on the side of the throttle body.

IAC is clean

mpgMike wrote: ↑February 28th, 2025, 8:55 am You said, "All tuned in open loop." What are you doing for tuning?

Being an XJ, you should have a distributor. An obvious question is how are your tune-up parts -- specifically cap, rotor, and wires? Could you possibly have a cracked ignition coil?

Using HPTuners with a wideband, disabled closed loop by raising the coolant allow temp to max. It’s a 2000 so it’s coil rail not a distributor.