I need help troubleshooting an ignition issue

[splashdown]

My '93 Ranger started cutting out while I was driving in town the other day. It was 100+ degrees out, and a few cylinders quit firing. I let it cool down over night, and when I started it I had all six firing. I figured it was probably my coil going out. I let my truck sit for quite a while with a bum transmission, so I figured it was time for a tune up. New wires, new plugs, new coil pack. I double checked everything then fired it up. While it ran better, I still had some dead cylinders. There was no fire from the back pair of wires on the coil this time. That makes me think it's the EDIS module. I haven't figured out where that is on my truck yet. Anybody know where it's at on a '93 w/ 4.0 5spd? Is there a source to get one cheaper than 150 bucks?

 

[Big Jim M]

Dead Cylinders???

My '93 Ranger started cutting out while I was driving in town the other day. It was 100+ degrees out, and a few cylinders quit firing. I let it cool down over night, and when I started it I had all six firing. I figured it was probably my coil going out. I let my truck sit for quite a while with a bum transmission, so I figured it was time for a tune up. New wires, new plugs, new coil pack. I double checked everything then fired it up. While it ran better, I still had some dead cylinders. There was no fire from the back pair of wires on the coil this time. That makes me think it's the EDIS module. I haven't figured out where that is on my truck yet. Anybody know where it's at on a '93 w/ 4.0 5spd? Is there a source to get one cheaper than 150 bucks?

A six cylinder engine with two dead cylinders don't run at all, or at the very least it hardly runs.. I'm thinking you have made the easyest mistake of all..
You have crossed two wires.
Big JIm

 

[splashdown]

You are correct about it hardly running. I wish it was just crossed wires. I referenced the manual to double check my wiring order was correct. I knew it was misfiring, so I put a timing light on each wire to see if I goofed up and didn't get a solid connection, and the back two wires on the coil pack (headed to cyl #3 on the passenger side and #4 on the driver side) aren't firing at all from the coil. From what I've read, the EDIS module controls the firing order in pairs, so my guess is that the control module is causing the issue.

 

[Bob Ayers]

You are correct. It is either the EDIS module, or the wiring/connectors between the EDIS and coilpack. Cylinders 1&5, 2&6, and 3&4 fire together, and on every revolution of the crank.

 

[splashdown]

I checked the wiring from the coil to the EDIS module, and everything looked good. I ordered a new module, and it should be here by Friday. I can't believe how much they charge for those little things. I shouldn't complain since I've had the truck for 10 years, and I've so far only replaced the water pump, trans/clutch, and a few window motors. Friday after work I may be back to puttering around in the Splash once again.