My 90 GXL just started acting up. It ran fine, then I parked it for 5 days, and now when I start it, idles perfectly and seems OK, but when I step on the gas pedal more than 10%, the car just bogs down and refuses to accelerate and check engine comes on and stays on. However, I can drive it as long as I only push the gas pedal 10% to 20%, anything more will start stalling it.
Anyway, I swapped cats and the O2 sensor with no luck. The codes are 17 and 27. I don't think it is the OMP simply because I can drive it and get the revs to past 3000 if I am easy on the gas pedal.
Does this sound familiar to anyone??

 

Try cleaning out the connection on the OMP.

 

It is the OMP, it will allow you to exceed 3000rpm, you just can't exceed a certain amount of pedal travel or it'll kick off the error. Replace and be merry.

 

yes, replcace and premix in the mean time if you HAVE to drive it. good luck. search the parts forum, they can be had for $100 bucks or so used.

 

OK thanks! I'll swap it out next.

 

Keep in mind if your MOP is fucked, it has likely taken your ECU with it. If you replace the MOP and it still gives you error code 27, chances are the section on the ECU that controls the MOP is fried too. You will have to replace the ECU most likely. That is the situation my 1989 GXL is facing right now.

 

Code 17 is a Feedback error for the oxygen sensor. I had the code on my 91 TII. It caused the car to go into limp mode when it popped up.

I had a broken O2 sensor wire somewhere in the harness. My fix was just to run a new wire from the o2 sensor to the ECU. I drilled a small hole in the firewall and ran the new wire right to the ECU. Fixed my code 17.

James

 

Let me know if that works for you, because i am experiencing the same problems with my 91 gtu