SanDiegoXJ
NAXJA Forum User
- Location
- San Diego, CA
Ok, so I changed the injectors in my 1994 Country, 4.0, Auto trans about 8 months ago. Aside from a resulting engine compartment fire :shhh:, the swap went great, and the Jeep has been running flawlessly. With gas prices as high as they've been, the Jeep kind of got left to the wayside for the last couple months (2-3).
I started it up yesterday, it smelled kinda funky but was idling nice. I figured the odor was just build up of crap from not being run in so long. I drove down the block to grab some coffee and come home. By the time I got home the jeep was idling funny and I was getting a check engine light.
Being '94 it only has OBD 1 and was giving error codes of 12, 27, 55
I just changed the battery before I started it, so that explains the 12, and 55 is the end of the codes, so it explains itself, but the 27 has me stumped.
From JeepHorizons.com I got the following:
27 Injector circuit isn't switching when it's told to (TBI)
OR (MPI) injector circuit #1 not switching right
OR (turbo) injector circuit #2 not switching right
OR (all 1990-) injector output driver not responding
- check computer, connections
From JeepForum.com I got the following:
27 Logic module fuel circuit internal problem or TBI injector does not respond properly to control signal
Any suggestions on the best way to diagnose this? I find it hard to believe an injector went bad from just sitting around for 2 months. I certainly don't want to rush right out buy a new PCM if that's not it. Is there another computer box along the way I need to worry about?
Could it be the result of a faulty tps or cps?
Any help is greatly appreciated.
Michael
P.S. I guess I should also mention, when revs hit about 3500 it feels like all 6 cylinders start firing again. Right now it sounds and feels like it's missing 1....although the power and roughness of idle seem to come and go. If I let it cool down, the problem isn't as noticeable. Today I jumped on the freeway and went about 45 miles with no problems and no CEL. As soon as I slowed for an immigration checkpoint, the miss started again and never went away....letting the engine cool back down now to see if it starts right up or if it's gone until it gets warm again.
I started it up yesterday, it smelled kinda funky but was idling nice. I figured the odor was just build up of crap from not being run in so long. I drove down the block to grab some coffee and come home. By the time I got home the jeep was idling funny and I was getting a check engine light.
Being '94 it only has OBD 1 and was giving error codes of 12, 27, 55
I just changed the battery before I started it, so that explains the 12, and 55 is the end of the codes, so it explains itself, but the 27 has me stumped.
From JeepHorizons.com I got the following:
27 Injector circuit isn't switching when it's told to (TBI)
OR (MPI) injector circuit #1 not switching right
OR (turbo) injector circuit #2 not switching right
OR (all 1990-) injector output driver not responding
- check computer, connections
From JeepForum.com I got the following:
27 Logic module fuel circuit internal problem or TBI injector does not respond properly to control signal
Any suggestions on the best way to diagnose this? I find it hard to believe an injector went bad from just sitting around for 2 months. I certainly don't want to rush right out buy a new PCM if that's not it. Is there another computer box along the way I need to worry about?
Could it be the result of a faulty tps or cps?
Any help is greatly appreciated.
Michael
P.S. I guess I should also mention, when revs hit about 3500 it feels like all 6 cylinders start firing again. Right now it sounds and feels like it's missing 1....although the power and roughness of idle seem to come and go. If I let it cool down, the problem isn't as noticeable. Today I jumped on the freeway and went about 45 miles with no problems and no CEL. As soon as I slowed for an immigration checkpoint, the miss started again and never went away....letting the engine cool back down now to see if it starts right up or if it's gone until it gets warm again.
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