was having problems with rough idle, misfires on acceleration, changed plugs, wires, still no difference. Couple weeks later changed cap and rotor, this cleared it up and it was running smooth. My son with the magic touch takes it out for a two hour, out and back ,on the highway and It comes back misfiring again. I changed out the plugs,wires, cap and rotor again,(about a month after the original tune up) still misfiring. I knew the plenum was leaking so I replaced that with the hughes kit. I was hoping that might clear it up but stll no good. I'm also getting an "injector 3 control circuit" code as well as cyl 8&6 misfire codes. I've run the ignition wires the way its shown in the service bulletin also. any one have any ideas? gettin a li'l frustrated with this thing. seems like an electric/ignition problem more than fuel delivery but I'm open to suggestions! thanks!

 

Check your cat, and see if it isn't getting restrictive. Also, have you replaced your pre-cat O2 sensor yet?

Swap #1 and #3 injectors, see if the problem migrates with the injector. If it doesn't, start going over the wiring with a fine toothed comb.

How old is your coil?

 

Thanks for the reply,I was thinking the coil, I'm sure its original(have the truck little over a year), I had changed the o2 sensor, after the cat, after getting a code for that. the pre cat sensor wouldn't show up on the code reader?

 

What brand O2 sensor did you get? And no, it won't necessarily set a code.

 

Im gonna point at the cat possibly being clogged from the plenum being blown. Extra back pressure from that will cause all kinds of fun issues. When my buddies(who drove a 96 ram) got clogged it was obvious--the CEL will blink at you. How long was the plenum out before you changed it? Any idea how much oil it was going through?

Id look into the coil first though, theyre cheaper. I know theres a way to check it with a volt meter, but cant remember for the life of me.

 

the sensor I used was a oem from the dealer, I have gotten that flashing cel ocasionally, when I accelerate up a hill, but when I back off it stops. i was going through about a half qt every couple weeks, or about 4-500 miles. not sure how long the plenum prob existed, have the truck a little over a year, noticed the oil loss after checking it after an oil change in late spring.found out about the plenum problem from this site. thanks for the suggestions!

 

Flashing CEL uphill? I bet the truck has no power on inclines. That says Catalytic Converter. Head to a muffler shop and get it pressure tested.

 

Injector 3 control circuit is a wiring issue with the injector. Make sure its plug in all the way, check for broken or lose wires. also switch your injectors around 6/8 to see if you moved the missfire. I would not consider the coil or 02 sensor as an issue. if the injector swap does not move the missfire I would start looking at compression issues. Considering they are next to each other i would be concerned. Start with a compression check and or leak down. Keep us updated.

 

100% Definately the cat. Those are the exact symptoms my buddy had on his 96. Fix that asap, a clogged cat will *** up your engine real quick. Thats the reason i gutted mine, dont have to worry about it if/when my plenum decides to eat it. Gutting it is a cheap and easy temp fix to you as well, be aware that you wont pass a smog test (I dont have to worry about it here in tx)and it will be very very loud


Keep in mind that this may not be the only problem, but im sure it is a large contributing factor


EDIT:I should add that if you go through with killing the kitty (gut cat) you will have to fool your rear o2 sensor into thinking its still good (or your cel will come on). This is easily achieved with the spark plug non fouler trick. Theres a write up on how to do it here in the faqs section.

 

we have emissions testing where I'm at so I guess I can't kill the cat, will check out the pressure on it though. thanks for all the help!