1989 I6 Engine Codes
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From: Rockport, IN
1989 I6 Engine Codes
Hi. I just got the codes from my 1989 E-150 with I6. They are 21 and 24. According to a chart I found at another site, 21 is the Engine Coolant Temperature sensor out of range and 24 is the Intake Air Temperature (IAT) or Vane Air Temperature (VAT) sensor out of range - IAT VAT. I am assuming this means they either need to be replaced or have been disconnected. The temp guage works just fine, but I am pretty sure that this EGT is something different. So, do y'all think I am on the right track? Should I just replace these two sensors or is there something else that could cause them to malfunction? Thanks.
Fleet Owner
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From: Kentucky
If you did not warm up the engine before running the KOEO test then the errors are user induced. Those can also be caused by running the KOEO test in very cold weather. If the engine was warmed up and the outside air temperature was reasonable, then they could be valid. What issue are you trying to resolve?
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From: Kentucky
The first part of the code check is called Key On Engine Off (KOEO) tests. If the tests pass, you will see a System Pass code of 11 flashed twice. Then the system will display any codes stored in Continuous Memory (CM).
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From: Rockport, IN
Ok. I just found a Popular Mechanics article that better explains how to do this procedure. I did it wrong. I do need to run the van for a while to let it heat up before I start the test. I also didn't run the test long enough. Like you said, I am getting those two codes because the sensors are not reading the temp they should be reading, something they would do if the vehicle was warm. I need to do this again tomorrow. Sorry about the mix up. I thought the procedure was the same as it is on my Chevy.
Fleet Owner
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From: Kentucky
It's always a learning experience. Glad you found some info to run the tests. Let us know what you come up with.
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From: Rockport, IN
I am sure there is something wrong with one of the sensors. The van runs well, but it's definitely running rich. I also get a very faint miss in it at around 50mph. I know it isn't something simple like the plugs and wires cause I just replaced them and the cap, rotor, and fuel filter. Also, every now and then it will hesitate when I give it gas.
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Fleet Owner
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From: Kentucky
If the KOEO test pass and there are no stored codes in CM then the sensors are most likely okay. The most likely cause of a rich condition, with no displayed error codes, is a faulty Fuel Pressure Regulator. The internal diaphragm can leak with allows fuel to be sucked into the intake from the vacuum port.
Pull the vacuum line off the FPR, cycle the key on/off a few times to pressurize the fuel line, then inspect the FPR vacuum port for signs of fuel. If there is a gas smell or obvious liquid fuel coming out that port, replace the FPR. The FPR could also be faulty by allowing too much fuel pressure to the injectors. You will need a fuel pressure gauge to check that.
Pull the vacuum line off the FPR, cycle the key on/off a few times to pressurize the fuel line, then inspect the FPR vacuum port for signs of fuel. If there is a gas smell or obvious liquid fuel coming out that port, replace the FPR. The FPR could also be faulty by allowing too much fuel pressure to the injectors. You will need a fuel pressure gauge to check that.
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Sorry it took me so long to get back to this thread. The van's future was in question for a while, but we have decided to keep it. I ran the KOEO test and got code 32 (EVR - EVP signal is/was low - EVR ). The first part of the test was fine. What does this code mean? I am guessing it has something to do with the EGR system, but I am not sure.
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EVP refers to the sensor on top of the EGR valve. This is the EGR position feedback signal back to the PCM. The output signal should be above 0.27 VDC when the EGR valve is closed. A bad EVP sensor, collapsed EGR diaphragm or open circuit can cause this code.
Measure the output signal with a DVM. For reference: Ford Fuel Injection » EGR Valve Position sensor (EVP)
Measure the output signal with a DVM. For reference: Ford Fuel Injection » EGR Valve Position sensor (EVP)
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