OK I have a 91 convertible completely stock. The other day the check engine light came on (I 've owned/own 7 RX-7's and never had a light so it's a little new to me). Anyway when the light comes on the car runs like **** it only accepts light inputs on the gas pedal if you push to hard it bogs down and chokes, gets all herky jerky. I checked the codes its either a 1 (trailing coil)or a 10 (AFM thermosensor) I say either cause i don't know how long the long should be as I said before never had a check engine light. So I have many parts I swapped out the Trailing coil and AFM. The problem still exists. The light is not on when you start the car it definately comes on when the gas pedal is pushed to far down to fast and maybe after so many minutes. I know my way around the car and do everything myself have owned the car for 5 years no probs. It seems to me like a fuel or air problem thats why it chokes under heavy pedal havn't had to much time to troubleshoot so any help would be nice, and if its been covered before I apoligize

Thanks

 

Sounds like it could be the OMP. If the OMP malfunctions it will put the car into limp mode so you don't run the car too much without oil injecting into the rotor housings.

 

Thats what one of my friends said but why is it not giving me that ECU fault if thats going on. I have another OMP sitting around guess I will try changing it out this weekend, unless there are any other good ideas.

Thanks

 

Nah, not the MOP. The computer takes time to sense something isn't right with the MOP. Does you symptoms happen all the time when you give it too much gas or does the light come on several minutes after starting driving and stays on?

 

I think the duty cycles for the long and short bursts are the same as the ones used by the cruse self-diagnostic.

Long ones are 1.2 sec
Short ones are 0.4 sec

Enough disparity to determine if only one shows up. I've had an error code that contained both long and short bursts. Long bursts can be seen, you can look away real quick, and it remains on when you turn back to it. Can't do it for short ones.

Edit: According to RotorWiki the times are

 

Under what one would say are normal driving conditions it comes on after awhile around 5 mins of driving. If I stomp on the gas it will come on instantly. I have driven for about 10 to 15 mins before it came on but that only happened once. So to answer your question I would lean toward it comes on after about 5 mins which would make me say OMP but why don't I have a fault, but I work with electronics all day so I know they don't always act like they should.

Thanks

 

Well I tried a different OMP it is still happeneing. Gives the same ECU Fault 1 long flash guess its time to check wiring wiring.

Thanks

 

This is highly likely the OMP limp mode. I call it limp-mode hell.

You may have fried the output section of the ECU. It happened to me.

There is a great big thread on this with a great deal of information.

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s5-mop-ecu-failure-diagnosis-710938/

I got a replacement (used) OMP that was known to be working when removed. I did all the diagnostic tests to determine if the 'new' OMP was good. It was, but the car still didn't run. I removed the ECU and found burned circuitry just like the pictures in this post. I got replacement ecu and all is well.

By the way, my old bad OMP tested good on all the tests from the FSM. I found the fault by using the test procedure from the above post.

Good Luck.