pls91fc

Car runs great from idle up to 8k rpm until 10 mins of idling or driving. CEL comes on and car sputters but does drives. Turn car off, runs great again and CEL comes on in ten mins exactly. Strange thing is CEL code does not stay in computer, can not get code.
I have had my OMP fail before and it held a code that pointed me to the OMP. Car isn't acting like limp mode when I lost my OMP.
Just replaced the TPS and adjusted it. This seemed to fix my pulsing idle but CEL did not get fixed.
Anyone experienced anything like this before? Thanks

misterstyx69

iTrader: (142)

Did you pull codes?

j9fd3s

iTrader: (3)

chances are that it needs a harness and or an ecu, and maybe an OMP too

pls91fc

As I stated, the code doesn't stay in computer. I tried to pull a code but nothing is there.

lduley

iTrader: (1)

We've seen your story before, many times, and it usually led to a bad OMP and ECU

you said you replaced the OMP before, did you replace it with new or used? And did you replace the ECU at the same time?

pls91fc

It was replaced with a used one. Did not replace the ecu at that time as everything checked out after replacing the OMP.
Car doesn't seem to be acting the same as it did when the OMP went. It would not let me drive the car for more than a minute and I couldn't step on the gas more than 30% when it went into limp mode. I was able to read the code that time as it stayed in the computer and came on every time I started the car.

satch

iTrader: (1)

Unplug your boost sensor and see if the ECU will show the error code. If it does not then you probably know the answer.

pls91fc

do you mean the pressure sensor? My car is an NA. Thanks If the error code doesn't stay my ecu is messed?

satch

iTrader: (1)

Boost/pressure means basically the same item. And yes to your last point.

pls91fc

Good call search. Unplugged sensor and code did not stay. Had a good ecu on the shelf and swapped out. Threw code 27 after driving for ten minutes.
Old ecu had a burnt resistor or two when I opened it up. Definitely should have replaced when my OMP went the first time. Now to do it all over again! Can OMP's be rebuilt or are my options still only new and used?


Backside




Inside

j9fd3s

iTrader: (3)

the OMP's can't really be rebuilt, but you could swap just the stepper motor, or the position sensor if needed.

my FC, has an FD engine and ECU in it, but its running an FC harness, so the OMP is an FD mechanical pump with an FC stepper motor and position sensor, so it plugs in.

since we're talking about it the 92-97 FD OMP has an identical stepper motor and position sensor, just a different harness connector