Hi. I have a 1990 turbo rx7. there are times when my car will not rev past 3500 rpm with the ac on and not over 1500 rpm with the ac off. it just stumbles and sounds like the fuel is being cut. This is in neutral. When i try to run the car the engine dies when i release thu clutch. This problem is random......sometimes when i start the engine first thing in the morning its fine and after 2km of driving the problem kicks in. there are times when i can do 10 km of driving. there are also times when it runs fine for 5 minutes then the problem kicks in i just shut the car off and wait five minutes then its fine there are times when i have no problems at all and there are times when i cannot use the car cuase the problem won't go away. already replaced the ecu, air flow meter, coils, spark plug, wires and alternator.
pls help

 

sounds like the car is going into limp mode, the OMP ( oil metering pump) might be failing intermitently,

 

do yo uhave any check engine lights? if its around 3500-4000 that is when the secondary injectors kick in so there could be a problem there.

 

i do not have a check engine light. this car used to be right hand drive then i converted it to left hand drive, after the conversion have not seen the ceheck engine light anymore.

 

you might want to check if your injector plugs are plug in to the right injectors. because if they arent plug in right then the same problem you are having occurs.
I had the same problem like yours.

 

what do you mean by injector plugs.......the primary and secondary injector wires are mixed up or the 1st rotor and the second rotor injectors are mixed up?

 

tried driving my car this morning when i first got it started it immediately had the problem engine pulses at about 2500 sounding like there is a fuel cut or an ignition cut or both. turned the engine off after twenty minutes started it it was normal. drove for about ten minutes the problem came back but when in gear while driving the revs will not go above 1500 rpm in fact i cannot drive it above idle rpms. once i limped the car back home turned the engine off and on about ten times and the problem persisted. left the car for 15 to twenty minutes and started it it was normal again. SOMEBODY PLEASE HELP I'M GOING CRAZY OVER HERE.

 

First I need to know what kind of engine you have. Is it turbo, does it have an egr valve, and do you know what year it's from. I also want to know how the hel! you donverted it to a lefty and why (for my won personal well being). I will asist you to the best of my knowledge

 

^ read the first post

 

sounds to me like something is loose cause your computer wouldnt bounce ack and forth between limp mode that much. I think your MAF plug is loose

 

My car is a 1991 savanna rx7 imported from japan. I bought this car from an auto dealer who imports cars from japan and converts them to left hand drive because it is illegal o use riht hand drive cars on the streets here in my country.

Drove the car a lot today to get a more accurate description of the problem.....today the engine started with no problem in it's first morning start. warmed it up for 10 minutes then drove it away. After about 15 mins of driving in medium traffic everything seemed normal. Reached a stop light and when the lights tured green the car would not reve above 1500(egine starts pulsating) rpm in neutral and when i pt it in gear not over 1000rpm. I then had to drive back shifting the gears at 1000 rpm or practically at idle...the engine just refuses to rev above 1000rpm. back home i poped the hood started the engine the roblem was still there, had a cigarrete and after smoking started the engine and it wass perfect. drove out again and after about 2 minutes problem was back.....parked the car for five minutes started the engine and it was fine again. was able to drive for about ten minutes then problem was back. limped the car home shut the engine off for ten minutes started the car and everything normal again.....i'm so lost.......oil pressure and water temp was normal i do not have a check engine light as it dissapeared during the conversion process from right to left.

 

A somewhat similar thing happened to me a little while back. Have you checked your TPS? Don't qoute me on this, but I'm pretty sure the ECU doesn't read TPS or doesn't read some ECU input until your ECT sensor reaches a certain "warm" temperature. Then it goes into official closed loop.

Here is where the problem could be. My TPS connector harness was VERY corroded, so I got in there with wire brush as best I could to clean up the spade connectors. I attached it back on, wiggled it, unclipped it, and repeated a few times to make SURE I was getting a good connection. That fixed mine up rea good.

On that note, when you have your connectore unplugged, you should test the resistance of your TPS from idle to WOT. Check for flat spots. If you can, I've heard its even better if you can back probe the connector while you have 12v to it, and sweep test the TPS measuring Voltage.

I'm pretty sure the problem you have is the same as I had. The fastest I could go would be like 55mph, I could never open the throttle more than 1-3%. Once I felt the problem I would try to race the engine up by flooring it, all I would hear is the Throttle opening up wide, and the engine stumbling at the same RPM.

 

Wherever i hear this problem I alway tell peopel to change their fuel filter (the one in the engine bay). I had this problem and that solved it.

 

when u do the filter check fuel pressure for a length of time.

 

what was the solution to this problem im having the same problemm exept mines runs fine then shuts off and after it shuts off it wont start if you dont give it gas but it doesnt 2k rpm

 

I'm having a similar problem 91 NA gutted Cats, except with mine, it will drive fine for 20-30 minutes then start to limp for 10-15 and out of no where it will jump right out of limp mode and drive fine. I have yet to find out what's causing it.

 

Are you saying you don't physically have a check engine light because of the conversion or you just don't have a check engine light on?

Really sounds like the car is going into limp mode because of an OMP failure. Before doing anything, you should pull the computer error codes to see what they say first. Post the codes here and we'll tell you where to start.