low power/engine codes
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low power/engine codes
I'm trying to get my truck running right and i'm stumped. It's an 89 f-250 heavy duty with a 5.8 and a4od. When i press hard on the accelerator, it just won't go, if i press too hard it misses or backfires. I can drive around but it's just not right. I checked the codes and i got code 12 and 65. My book said 12 is the byp valve, or coking in the throttle body. took the throttle body off, didn't look too bad, cleaned it, even the little passageways, put on a new byp, still same problem and codes.
I trying to tune this up and get it running right. I have replaced plugs, wires, distributer, rotor, fuel filter. checked the compression, it's at least 120 in all the cylinders.
please help me, i don't know what to do next.
Brian
I trying to tune this up and get it running right. I have replaced plugs, wires, distributer, rotor, fuel filter. checked the compression, it's at least 120 in all the cylinders.
please help me, i don't know what to do next.
Brian
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Ok, I do have a random theory. Is it possible that a valve cover leak could case this code 12 because of leaking vacuum? It sounds like an exhaust leak on the passengers side, but I can't feel anything at the exhaust manifold on tailpipe union.
Brian
Brian
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The air injection system on these old trucks is convoluted and prone to rust and breakage, it's likely the exhaust leak you hear is from a part of this that's attached to the exhaust.. likely behind the motor. You may have some plumbing back there that looks like this below, inspect the valves and plumbing for broken parts.
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I've looked at this emmisions stuff real hard and I just can't seem to find any leaks. The pipes don't even look rusty, and the hoses all appear to be intact. could an injector problem cause the code 12 low rpms? i tried with my stethiscope to pinpoint the noise, kind of like a tic, but i can't find anything. could an injector make this noise if it's not firing properly? would something with a clogged pcv cause this, i haven't replaced that yet?
Thanks,
Brian
Thanks,
Brian
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No, I don't get any codes with the engine off, either continious or memory. But, good news, the code 12 seems to have dissappeared and it's running again. I'm kind of happy, but i don't know why it is fixed, so i'm a little worried it will be something intermittent.
Brian
Brian
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From: Ottawa, Ontario
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Sorry, i meant the 11 all clear. I tried to take the truck out yesterday, and the problems came back, with the KOER code 12 and 65. I'm just trying to figure out which area to look in. I think i will check the pcv and injectors next, because i don't know where else to look.
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From: Easton,Ks
For the 12 code you may have a bad plug or wire going to the IAC valve (aka byp valve).
Or maybe a bad vacuum leak somewhere. I do not think the valve cover would do it.
The 65 just means you did not goose it when the time came or if you did and the engine rev up the computer did not see the engine rev up.
This would mean bad wiring from the PIP sensor to the computer.
Or maybe a bad vacuum leak somewhere. I do not think the valve cover would do it.
The 65 just means you did not goose it when the time came or if you did and the engine rev up the computer did not see the engine rev up.
This would mean bad wiring from the PIP sensor to the computer.
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thanks,
I checked the voltage at the IAB wires and it was good. If not the valve cover, what about the lower intake manifold gasket? would it be possible if the cork part was degraded it would cause a problem like this?
I checked the voltage at the IAB wires and it was good. If not the valve cover, what about the lower intake manifold gasket? would it be possible if the cork part was degraded it would cause a problem like this?
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The 65 just means you did not goose it when the time came or if you did and the engine rev up the computer did not see the engine rev up.
This would mean bad wiring from the PIP sensor to the computer.[/quote]
still trying to figure this out. How can I test the PIP sensor and wiring. can this sensor go bad. maybe this is my problem and i missed it the first time. can i test the voltage at the pip sensor?
thanks!
This would mean bad wiring from the PIP sensor to the computer.[/quote]
still trying to figure this out. How can I test the PIP sensor and wiring. can this sensor go bad. maybe this is my problem and i missed it the first time. can i test the voltage at the pip sensor?
thanks!
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From: Easton,Ks
You said that you changed the Distributor.
The PIP sensor is inside the the Distributor so you changed the PIP sensor when you changed the Distributor.
As for the wiring you would have to ohm it out from the distributor to the computer plug.
Are you sure that you just did not goose it when the time came?
The PIP sensor is inside the the Distributor so you changed the PIP sensor when you changed the Distributor.
As for the wiring you would have to ohm it out from the distributor to the computer plug.
Are you sure that you just did not goose it when the time came?
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From: Easton,Ks
If you changed the Distributor and did not tear the Distributor all the way apart to the last part then you changed the PIP sensor.
What test is giving the 12 and 65 (KOEO, CM, or KOER)?
They have different meanings.
What test is giving the 12 and 65 (KOEO, CM, or KOER)?
They have different meanings.