AHHH!! Need help!
#1
02-23-2015, 09:36 PM
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AHHH!! Need help!
94 Dodge Dakota 5.2L
Code 27 (Inj #5) and Code 45 (New code)
Tried to fix code-27 doing the following:
Checked the following:
I am not sure, but now the only resolution I can reach is that a driver in the computer is bad, maybe from a surge and needs another replacement? but before I commit to the 4th computer, want to make sure....
Code 27 (Inj #5) and Code 45 (New code)
Tried to fix code-27 doing the following:
- Replacing PCM (3 times and a check)
- New Injectors
- New plugs, wires, distributor
- Alternator
- Fuel pump assembly
- New ground wire from inj#5 to PCM
- New injector harnesses
- New pcm harness
- new battery thoughts?
Checked the following:
- Grounding wires from injectors to PCM register @ zero resistance
- Checking 60-way for resistance to ASD relay, checks out okay (15+)
- Fixed a few splices here and there
- Checked groundings
I am not sure, but now the only resolution I can reach is that a driver in the computer is bad, maybe from a surge and needs another replacement? but before I commit to the 4th computer, want to make sure....
I am losing my mind over this!
#3
02-24-2015, 05:16 PM
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progress
Figured I'd follow up in case anyone has similar issue.
20+ key starts clears the hard code. Pram will still hold code 27 in memory, you can clear history with positive + negative cable tap. But computer will need to relearn itself.
So far after 20+ startups, no engine codes appear..
20+ key starts clears the hard code. Pram will still hold code 27 in memory, you can clear history with positive + negative cable tap. But computer will need to relearn itself.
So far after 20+ startups, no engine codes appear..
#5
02-25-2015, 05:12 PM
To clear the computer just disconnect the neg cable for 5 minutes. Arcing the cables is not good.
Seems like the injector wiring may have a short. IDK how to deal with this but I have found several sets of instruction on searching for how to check continuity etc with multi meters.
I found this here http://www.naxja.org/forum/showthread.php?t=970033
Poster is Mathew Currie
Part of one post
"You can do a very quick check to determine whether the problem is in the injector or the harness, by running the engine, and unplugging the injector you suspect is bad. If it's a bad one, nothing will change. If it's a good one, the engine will briefly bog, then recover. Now swap the connector that tested bad with its nearest neighbor, start the engine again, and repeat the test. If the same plug is dead, it's the harness. If the same injector is dead, it's the injector."
Further down he posts this.
"My stepson's 93 had the same problem which turned out to be a bad splice in the harness. I won't go through all the things I did to try to fix and diagnose it, except to say that after I was done nothing on that engine needed tuning up or replacing for years to come, and I still have a spare junkyard ECU! It turned out to be a bad splice in one of the positive lines to an injector, which had just enough resistance in it to allow it to work when cold, but it heated up as it went, and the resistance would rise just enough to cut it out. It would often run just fine for a half hour or more, and then appear after it had been parked and shut off, when the engine bay heats up. I even tested it with an injector tester and it passed, but the voltage when it cut out was something like 9 volts, just enough to cause the misfire. I finally caught it with the wire swapping test when it was hot, and then took an ohmmeter reading to confirm. After many days and many bucks of farting around, the actual repair - a soldered-in bypass for the bad splice - took about 10 minutes."
The OP posted near the bottom
Hey there,
Unfortunately I sold the Jeep to another Jeep guy who had more time but he did confirm there was a short.
Hope that helps,
Skip
Seems like the injector wiring may have a short. IDK how to deal with this but I have found several sets of instruction on searching for how to check continuity etc with multi meters.
I found this here http://www.naxja.org/forum/showthread.php?t=970033
Poster is Mathew Currie
Part of one post
"You can do a very quick check to determine whether the problem is in the injector or the harness, by running the engine, and unplugging the injector you suspect is bad. If it's a bad one, nothing will change. If it's a good one, the engine will briefly bog, then recover. Now swap the connector that tested bad with its nearest neighbor, start the engine again, and repeat the test. If the same plug is dead, it's the harness. If the same injector is dead, it's the injector."
Further down he posts this.
"My stepson's 93 had the same problem which turned out to be a bad splice in the harness. I won't go through all the things I did to try to fix and diagnose it, except to say that after I was done nothing on that engine needed tuning up or replacing for years to come, and I still have a spare junkyard ECU! It turned out to be a bad splice in one of the positive lines to an injector, which had just enough resistance in it to allow it to work when cold, but it heated up as it went, and the resistance would rise just enough to cut it out. It would often run just fine for a half hour or more, and then appear after it had been parked and shut off, when the engine bay heats up. I even tested it with an injector tester and it passed, but the voltage when it cut out was something like 9 volts, just enough to cause the misfire. I finally caught it with the wire swapping test when it was hot, and then took an ohmmeter reading to confirm. After many days and many bucks of farting around, the actual repair - a soldered-in bypass for the bad splice - took about 10 minutes."
The OP posted near the bottom
Hey there,
Unfortunately I sold the Jeep to another Jeep guy who had more time but he did confirm there was a short.
Hope that helps,
Skip
#6
02-28-2015, 04:42 PM
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Thanks !
It may help, I was leaning in that direction. There is a new harness (injectors harnesses and computer harness), I will swap injector harnesses to see if code changes to a different injector. The + input comes from the ASD splice, at one test, all registered good volts, but as you said, it could change at any time given the condition of the splice. The computer probably registers a drop and cuts out the injector immediately. not sure what the range the computer decides to do so, but could be a possibility... now just gotta find the splice.. I'll keep everyone posted.
Today, I just started unraveling all the wiring, found another bad splice under the ASD box, but it was for the headlights(black with neon stripe x2).. that explains why the low-beams sometimes worked. already fixed the other common splices by the ASD box.
It may help, I was leaning in that direction. There is a new harness (injectors harnesses and computer harness), I will swap injector harnesses to see if code changes to a different injector. The + input comes from the ASD splice, at one test, all registered good volts, but as you said, it could change at any time given the condition of the splice. The computer probably registers a drop and cuts out the injector immediately. not sure what the range the computer decides to do so, but could be a possibility... now just gotta find the splice.. I'll keep everyone posted.
Today, I just started unraveling all the wiring, found another bad splice under the ASD box, but it was for the headlights(black with neon stripe x2).. that explains why the low-beams sometimes worked. already fixed the other common splices by the ASD box.