Check Engine light, no codes
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Check Engine light, no codes
It's a '95. Started with intermittent check engine light with rough idle and low power and no smoking. It happened 3-4 times just after hot or cold start, but would clear itself and run fine. Because the local freeby code readers don't work on it, I took it to a reputable diesel shop today.
Almost had to turn around because it was acting up, and being persistent. It did clear up and ran fine to town. When he started it up (while plugged into the diagnostic thing) it was rough again w/ check engine light on. After about 5 min., he told me it must be mechanical because there weren't any codes.
I was planning to have them replace the glow plugs anyway (I don't feel like bending over fenders anymore) and it wouldn't clear and run right, so I left it there for a Tues. appt.
The question: Does this sound like a VC gasket connector and or the wire harness under the VC? They are to be replaced already with the glow plugs.
Jess
Almost had to turn around because it was acting up, and being persistent. It did clear up and ran fine to town. When he started it up (while plugged into the diagnostic thing) it was rough again w/ check engine light on. After about 5 min., he told me it must be mechanical because there weren't any codes.
I was planning to have them replace the glow plugs anyway (I don't feel like bending over fenders anymore) and it wouldn't clear and run right, so I left it there for a Tues. appt.
The question: Does this sound like a VC gasket connector and or the wire harness under the VC? They are to be replaced already with the glow plugs.
Jess
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From: OH
Sounds like IDM 2 me also, it acts the same as a module would when bad on a gas job.Run funny then clear up or die and not start ect.That's what happened when my IDM went out. Check ur harness for resistance theres a good post on that. 
Lead Driver
Joined: Oct 2003
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From: Madison, WI
There's ALWAYS a code. Even with a perfectly running engine, the diagnostic should return a P1111, which is the code for "all systems go". If the shop literally go NO codes, that's an indicator that their equipment cannot communicate with your truck. Not at all uncommon, since the OBS PSD uses a non-standard "OBD-not-quite-II" protocol. If an IDM problem sets the CE light, there is without question a code stored in the PCM.
But the symptoms along with the CE light could mean any number of things. UVCH / wiring and IDM as mentioned above are two prime suspects. One poor-man's IDM test - remove it and shake it, listen for water sloshing. They're known to take in water from the hood / fender parting line.
But take it back to that shop and confirm that they're actually communicating with the truck. See if they're able to read live data, such as EOT, injection pressure, etc., PSD-specific values, not just RPM. See if they can do an injector buzz test. If they're not able to do all that, they don't have the equipment necessary to help you fix your truck.
But the symptoms along with the CE light could mean any number of things. UVCH / wiring and IDM as mentioned above are two prime suspects. One poor-man's IDM test - remove it and shake it, listen for water sloshing. They're known to take in water from the hood / fender parting line.
But take it back to that shop and confirm that they're actually communicating with the truck. See if they're able to read live data, such as EOT, injection pressure, etc., PSD-specific values, not just RPM. See if they can do an injector buzz test. If they're not able to do all that, they don't have the equipment necessary to help you fix your truck.
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From: Western NC
According to the owner's manual a CEL that comes on and then goes off, without codes is related to an empty fuel tank or low fuel pressure from the fuel tank.
Mine would do that when I let off the throttle while driving. What I found is the pickups needed to be replaced and the tanks were full of gunk.
Mine would do that when I let off the throttle while driving. What I found is the pickups needed to be replaced and the tanks were full of gunk.
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Lead Driver
Joined: Oct 2003
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From: Madison, WI
The owner's manual doesn't distinguish between our trucks and the gassers. I could see this happening with a gasser, since, presumably, their PCMs monitor and control fuel pressure. Our trucks do neither, so I wonder if that even applies to the OBS PSD. I could see the fuel filter light coming on possibly.
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From: Western NC
To quote the "F-Series Owner Guide" on page 87 in bold:
"Note: If your light truck is equipped with dual fuel tanks, the CHECK ENGINE light may come on if fuel is restricted to the engine or if the fuel flow is momentarily disrupted because of an empty fuel tank before you switched to the auxiliary fuel tank. This condition is normal and the light should go off after full flow is restored."
This is what I refer to, since my CEL light came on and didn't set any codes. So the light can come on and not set any codes according to the owner's guide. Just one more thing to consider when discussing this problem.
"Note: If your light truck is equipped with dual fuel tanks, the CHECK ENGINE light may come on if fuel is restricted to the engine or if the fuel flow is momentarily disrupted because of an empty fuel tank before you switched to the auxiliary fuel tank. This condition is normal and the light should go off after full flow is restored."
This is what I refer to, since my CEL light came on and didn't set any codes. So the light can come on and not set any codes according to the owner's guide. Just one more thing to consider when discussing this problem.
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Thanks for the help -
The UVCH wires were melted at one of the connectors. He also admitted that I'd probably have to pay the Ford dealer to read the codes. It's running great, so I won't be spending that money just yet. Jess
The UVCH wires were melted at one of the connectors. He also admitted that I'd probably have to pay the Ford dealer to read the codes. It's running great, so I won't be spending that money just yet. Jess
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