Head Bashing 101, Please Help the confusted

[Lukafer]

Hey, I got a 1986.5 model with the 7mge engine. I've been having a problem with the car running sweet when it's cold, but horrible when it gets to operating temperature.

I've replaced the fuel injectors with new o-rings, replaced all the gaskets from the intake manifold up to the throttle body. New o2 sensor and water temp sensor, got a msd blaster coil to replace the old one. 8mm msd spark wires are new, new cap/rotor, oil is good, and compression is 175-180 throughout. No fluid leaks as far as I have noticed.

I just can't seem to figure what would be causing this problem. Is is the mass flow sensor or the egr? If anyone has run into a problem like this before drop me a line, I'd appreciate any help offered.

Lukafer

[theWeezL]

sounds like it running fine on closed loop and then having a problem when the ECU takes over.

Most likely electrical/sensor issue of some description. Run a diagnostic and check for codes, as almost all sensor failures will generate one.

Also, please describe the way it runs hot...missing? backfire? smooth idle/but no power off idle? the better the description the easier to help

[Lukafer]

I would say when it runs hot that it is rough, loss of power and sounds like it's missing. It doesn't backfire, but sounds like it wants to. I believe last time I checked it gave me a code 14 and 24. Not quite sure what that means I should be fixing though.

Lukafer

[theWeezL]

code 14 - Ignition signal

diagnosis: NO "IGF" signal to ECU, "A" times in succession, "A" 7M-GE

6-8 7MGTE 3
trouble area: lgnition and ignition coil circuit, Igniter and ignition coil, ECU

(I have no experience wiht that code, maybe someone else can help ya)

code 24 - lntake Air Temp. Sensor Signal
Diagnosis: Open or short circuit in intake air temp. sensor signal (THA)
Trouble area: lntake air temp. sensor circuit lntake air temp. sensor ECU

on the code 24, if your NA then the sensor is built into the AFM, and it means you will likely need to replace that. It could also be causing the poor running conditions. I believe on the 7MGTE the temp sensor is on the pipe inboard of the AFM (I dont have a turbo to go look at.)





as for other general reasons that may be affecting your running condition, I used to throw out plugged cat as a possible reason but never really having had experience with it until recently. I had a plugged cat in the 89 I just bought and I can now say from experience that it does happen and can cause some really strange behavior. After your car is warmed up go listen to the sound coming out of the tailpipe. Also put your hand in front of the exit and just feel the gases coming out. If it pulses a little and sounds like a normal exhaust Its probably not the cat. BUT, if it sounds more like hiss than pulse, and you cant feel pulsations of the exhaust..then suspect a plugged cat.