Cummins93

Any chance your timing chain is worn? You tested fuel pressure under load/ while the problem is happening?

This is completely stolen and I take zero credit for it...and zero responsibility for what people do with it.

Wobble extension kit from harbor freight. Great for the CPS also good for the lower intake/exhaust bolts.

The 91 to 95 dash tach doesnt interpret anything but the 96 ecu tach signal. The 96 ecu is a one year PN. don't try to flash a 97 to 99 to the 96 cal. The harnesses are available with a week lead time. Ive been working on a piggybacked standalone that seems to work very well.

Hey I'm that guy! I won't get too sales pitchy but I will explain my reasoning for making such a time consuming (to build) harness. Once you factor in the low and high rough estimate for hardware changes with a full harness swap you are at 170-290 (depending on what quality sensors you purchase) plus whatever the harness cost. Socketing the ECU isnt impossible but it is time consuming and you need to know what you are doing. Diagnostics are much easier. If you suspect the obd2 ecu has faulted you can simply unplug the conversion harness and install the stock ecu in about 5 minutes. The conversion harness also comes with a built in 8 foot long obd2 harness to reach into the cab and provides all live data that would normally be available in the 96 year. Trevor

Thanks. Yea those keyways look much different than what I have on the diagram.

Can you post pics of the ecu plugs? Emphasis on the key ways and rough dimensions if you can. A simple dial caliper will be accurate enough.

What do you have? It can be in terrible condition as long as the connectors are intact. I have some test pieces coming by the end of the day. If I can confirm they line up then I may have a working solution.

I would like to reproduce the connectors and make a pnp harness for the speeduino. I currently have them for the JTEC.

Here is my current understanding of the early controller types. Pre 87 had a single ecu connector? The 4.0 XJ and MJ had the 32 and 24 way female harness connectors for the renix ecu from 1987 to 1990? I can source the harness connectors but the ecu 56 way is rather difficult to find. Does anyone have a bad renix ecu and/or harness?

I'm playing the long game waiting for koenigsegg to catch the Jeep addiction. Then they can make a solenoid controlled aluminum crossflow head. Probably shave off half the total height of the head. For current options of adding power to the 4.0 forced induction is the way to go. FI stroker is even better.

Feel free to PM with any questions or requests. Ill get back to you with some fuel trims.

The JTEC will compensate for those size injectors. I second giving Chris a call, he can do quite a bit to the proramming of these ECUs. If you are looking for just bolt on and go stuff that is understandable as well. I do sell injectors 4 or 12 hole, bored TBs and crank sensors. Let me know if I can help you out.

I didn't forget about the MJ guys. I have been putting together a drop in speeduino for tuning using tunerstudio. I have been testing and tweaking my set up. This ecu will tap into the necessary sensor inputs and sever the 6 injector outputs and coil output. The on board map sensor is 2.5 bar but for whatever reason you have you could run a 4bar. The unit has a bunch of extra functions. I don't have a renix system to test on but I see no reason it couldnt be done.