300-6 missing when hot, something with the computer?
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Joined: Feb 2002
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From: Oregon
300-6 missing when hot, something with the computer?
My '88 300-6 misses when it is hot. It starts when the thermostate opens. I changed the plugs, wires, cap, and rotor, trying to fix it. This didn't work. So I unpluged the wire going into the top of the thermostate, and it runs fine. But now I have a "Check Engine" light. This makes me think it must be a sensor, but how do I know which one? I am trying to sell it, so I think I might just leave the wire dissconnected, but the "check engine" light is still on. Please help.
Thanks,
Lars
Thanks,
Lars
Postmaster
Joined: May 2002
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From: Broken Arrow, OK
300-6 missing when hot, something with the computer?
The sensor in the Tstat housing is the coolant temp sensor and it will create the symptom you describe. They are fairly inexpensive as sensors go. Replace the CTS and it will probably fix your problem. It runs fine with it unplugged because the PCM defaults to the inlet air temp sensor for temperature data when there is a CTS fault.
Post Fiend
Joined: Nov 2002
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From: Memphis, TN
300-6 missing when hot, something with the computer?
Before throwing money at it, pull the codes, and test the sensors with a multimeter and the Haynes manual procedure.
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Joined: Dec 2002
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From: Pittsburgh
300-6 missing when hot, something with the computer?
My 95 does the same thing. Where exactly is this sensor? I will pull the wire off on my way home from work and see what happens. Are the 1988 4.9's speed density also?
--Ray
--Ray
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300-6 missing when hot, something with the computer?
The sensor in the thermo housing is the coolant sensor for the pcm and the temp sensor for the temp gauge is at the back of the engine passenger side under the last intake tube.
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300-6 missing when hot, something with the computer?
I have an F-150 4x4 with a 300-6 FuelInjected, it misses when at medium throttle, 3rd or 4th gear.. approximately 50K (or 30MPH) and also between 70 and 80K (45-50mph). It also tend to stutter in second if I am not pushing it hard, it accelerates fine and runs well when on the test gear, I can't find where the stuttering or the aparant missing comes from when at medium or cruise throttle speeds....
Postmaster
Joined: May 2002
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From: Broken Arrow, OK
300-6 missing when hot, something with the computer?
Gizmos, do a search for EGR restrictor and you'll probably find a solution to your problem.
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300-6 missing when hot, something with the computer?
Silver Streak - The problem was with the EGR System, Once it was bypassed the problem went away. Definately need to have that fixed. Thanks
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From: sanleandro
300-6 missing when hot, something with the computer?
if you take a piece of wire and plug it to the two wires that go to the computer one is one a single wire the other has multiple if you take the other end of the wire and plut it to the left of the two ports the are side to side withe the ignition off then turn it on don't start let all clicks finish for about 30 sec then turn off wait 15 sec then pull wire then turn on for 30mor e without starting and shut off wait 15 sec then your computer will have done a self test and cleared all codes and the problem should stop
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