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Topic: Check engine lights on but runs good (Read 1255 times) previous topic - next topic

Check engine lights on but runs good

Hello my 1988 Turbo Coupe check engine light comes on and goes off when I get on the gas I used my code reader codes came up 28,  42,  53, 67, it was cold outside but I got it to operating temperature I recently bought the car the check engine light was on I am trying to narrow down the problem I'm thinking it just might have too much fuel pressure maybe a bad fuel pressure regulator what I have done so far to fix it is tune up with all Motorcraft parts new throttle position sensor the car is mostly stock from what I can see fuel gauge does not work and also boost gauge does not work but it runs very well thanks for the help

Check engine lights on but runs good

Reply #1
28 Turbo--Vane air temperature voltage out of specs during self test.
28 memory-- Loss of ignition diagnostic monitor.
42 KOER self test--Oxygen sensor signal rich.
42 memory--Oxygen sensor signal not switching. Rich indication
53 --Throttle position sensor voltage too high.
67 KOEO self test--Neutral drive switch is open or AC was on during test.
67 memory--Clutch switch failed. Should give neutral drive gear signal when clutch is depressed.

Check engine lights on but runs good

Reply #2
I retested the car today when it warms. last night when I did the test it was below freezing outside. Today the only codes it was bringing up 42c, and 53c, so now it's just two that I have to deal with do you think the fuel pressure regulator will fix 42? And I can double-check the throttle position sensor voltage it should be at 0.95 volts at idle correct

Check engine lights on but runs good

Reply #3
The oxygen sensor code is either a wiring issue or a bad oxygen sensor. If the oxygen sensor is old it may just be bad or worn out.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

Check engine lights on but runs good

Reply #4
Okay I will also replace the oxygen sensor with a new one. And I'm going to replace the fuel pressure regulator give that a shot also. When I replace the spark plugs they looked kind of black so I'm thinking it's running rich I'm not sure if it has the stock fuel pump in the tank

Check engine lights on but runs good

Reply #5
The new oxygen sensor did not help throttle position sensor is correct and also fuel pressure is correct does anybody have any ideas maybe the turbo is leaking oil into the motor or the exhaust? And I'm still getting codes 42c and 53c

 

Check engine lights on but runs good

Reply #6
53 still says voltage is too high and 42 is still rich.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com