CPS position?

[mrtappan]

I started this project about two years ago and finally got around to finishing the wiring. I cannot get the engine to fire off. It is getting a signal (timing light flashes) but it will not start.

I had the factory harness that I'm using run on an engine stand WITH the ECU and distributor I'm using. So I know the harness, ecu, and distributor work. I have a 4.0 flywheel on the engine.

If it matters, it's an OBDI setup from a 1991 Cherokee. I have the OBDI distributor installed (old style, pickup under stator).

I tried and tried and tried to find a decent post about the cps sensor location and bracket. I remember using one to make the bracket (probably Martysocal one, but I cannot find any of his old stuff). I also can't find a single picture of where the pickup would be in reference to the flywheel timing marks are. Info on where it should be on the fourth mark range from "the center" to "trailing end."

In case anyone wants to point out my obvious mistake if you see it, please do. This is a picture of where my pickup is at *4BTDC. The lower red line is on the fourth tab on the flywheel. The upper red line is on the long solid area between sets of tabs. I thought I kept reading that you set the pickup at *4BTDC. I think I'm too far past the fourth mark?

If anyone has any old pictures or current links to any of Martysocal's stuff I' love to see them. I haven't had any luck myself. I've found plenty of broken links and a few pictures with watermarks so big they're useless.

[Eagle_SX4]

What transmission are you running? The AX15 and AW4 have pre determined spots for the CPS and there is no alignment needed which is why you are having a hard time finding info on it.

One thing to check, is to see if at top dead center on cylinder #1 (front most cylinder) the distributor rotor is pointed at or just past #1 spark plug wire.

[mrtappan]

I'm using a T5 with the bellhousing cut (I think I had Novak cut it).

Distributor is in correctly. I have spark and injector pulse. I made a ferrous bracket and used a magnet to make a adjustable setup for the pickup. Moving it around I can "almost" get it to start. It seems like the pickup has a very very small window of where it can be. I think I'm just going to have to do a ton of trial and error moving it around until I find the sweet spot.

My original bracket is aluminum and was made using old Martysocal pictures and measurements. I must have got them wrong somehow or perhaps I'm just a tiny bit off.

[Eagle_SX4]

I have run a T5 behind a 91 4.0 in my Eagle and my solution was a Hesco harmonic balancer crank trigger setup it works great. They make one for V-belts and one for serpentine belts.

https://hesco.us/products/30798/electri ... -hes9199ed

https://hesco.us/products/30791/40l-con ... t-hes42ved

When I was originally setting up the fuel injection on it I read several places that the flywheel stays with the transmission. So I never tried to use a 4.0 flywheel with the T5.

[mrtappan]

T5 behind the 4.0 engines is fairly common. A lot of people opt for the new AX15 but my jeep had the t5 and Dana 300 so I just rebuilt them. The t5 isn't a fancy transmission but even though I did a stroker with a cam, it's a very light build. I just built it to build it basically. I don't plan on actually mud riding it, rock climbing, etc. I'm just going to drive it around on sunny days and enjoy it.

Anyways, I may have to just suck it up and buy the Hesco. I'm going to wiggle the sensor around a bit more and double triple check everything. If I can't get it right, then that Hesco setup is the only option.

[Eagle_SX4]

Make sure you have an adequate heat shield on your slave cylinder. The 4.0 exhaust cooked the first slave cylinder I had.

[6spdYJ]

There were two different flywheels depending on what year. Generally OBD1 and OBD2. The position of OBD1 is about 1 o'clock as looking at the open end of the bellhousing. OBD2 are at about 9 o'clock. The OBD1 are a two tab sensor that drops in from the top and screw into the back of the bellhousing flange. OBD2 are a round sensor that pushes into a hole with one screw hole that goes into a boss on the passenger side of the bellhousing. Being a 91 harness, you're likely working with the two tab setups. As long as you have the OBD1 flywheel, you should be good.
The way I did mine was to cut the flange section off of the internal throwout bearing bellhousing between the two bolt holes. I bolted the piece (template) to the motor side of the 6 speed housing and drilled through the CPS mounting holes through the 6 speed flange. Tap them to 6mm x 1 and then use a dremel to open up a hole in the body of the bellhousing. It was cheaper and faster to drill and tap a couple of holes than to buy another flywheel and extend the harness and change the sensor connection.