1992 Ranger running on 2 out of 8 plugs

[michaewlewis]

Working with a 1992 Ranger, 4 cylinder, 2 wheel drive. The problem is that I'm only getting spark on the #2 & #3 cylinders on the exhaust side.

The ignition coils tested fine with an ohm-meter (tested them myself, and then had AutoZone test them). Still not satisfied, I got another pair of coils from the junk yard to see if they would work. No luck with those either. I'm getting the exact same problem, only getting spark in the same plugs.

The ignition control module has been replaced with one from the junk yard (same truck as the coils), and tests fine.

I thought that the catalytic converter might be plugging something up and restricting exhaust flow, so I took that off. The insides of the thing have been pretty badly melted, presumably because it's trying to burn off the fuel released from 6 non-sparking cylinders. Taking that off didn't make a difference, it just showed me a different problem.

I've also replaced the crankshaft position sensor & spark plugs. I tested the spark plug wires and they seemed fine to me so I didn't replace them. Fuel filter is clean and I'm getting plenty of fuel pressure.

Now I'm just looking for help figuring out what to check next. Any ideas?

 

[Jolly Roger]

Did you check your spark plugs for cracks in the porcelin. I had that problem one time one time trying to get around every thing with extentions and knuckles. Thay would fire only part time or not at all. How about pluge wires for resistance?

 

[michaewlewis]

Did you check your spark plugs for cracks in the porcelin. I had that problem one time one time trying to get around every thing with extentions and knuckles. Thay would fire only part time or not at all. How about pluge wires for resistance?

I addressed your suggestions in my original post.

I've also replaced the crankshaft position sensor & spark plugs. I tested the spark plug wires and they seemed fine to me so I didn't replace them.

Any other ideas?

 

[steve63]

do you have the coil packs pluged in right?,i hear they can be finicky.

 

[michaewlewis]

do you have the coil packs plugged in right?,i hear they can be finicky.

Ya... I've checked and double checked. The plug assignment is labeled on the coil pack. The weird thing is that the Hane's manual gives a somewhat different layout for the connections on the coil packs than the coil pack itself gives. I've been assuming that the coil pack's label is the one to go with.

 

[v8318cid]

Unless you can confirm the packs have been altered or changed, go with what the packs say. When in doubt, though, go with the layout on the tech section. I have the same year you do and my layout has been nothing but trouble. Of course, that was before I realized I had a bad pack.
Here's how mine worked out (which I believe matches the tech library diagram):
Rear (primary) coil pack :
3|1
2|4
Front (secondary) coil pack :
4|2
1|3
Several diagrams I have found unfortunately don't have the packs located in the same places and often lead to discrepancies. Best I can say is if your firing order is 1,3,4,2, match your coils so that the individual coils are paired with cylinders that are 180 degress opposite. Make sure that your #1 plugs are attached exactly as shown or you'll get a PIP failure code and the CEL will light up.

 

[michaewlewis]

I haven't tried any other configurations than what's labeled on the coil packs. But I think if the coil packs are plugged in wrong, they would still give a spark, just in the wrong timing. As it is now, I get no spark at all, except in two cylinders.

Thanks for your ideas guys, keep em coming!