I know this isn't SUV or truck related, however I have posted this problem on several other sites and no one seems to know what is wrong. I have had plenty of suggestions, but so far nothing has worked, so here it is....


I own an 85 MR2 that recently had a rebuilt engine installed. The engine runs great except for one thing; when you reach 6000RPM the car quits accelerating, almost as if you took your foot off the gas. If you keep the gas to the floor, it holds steady and won't accelerate, even downhill. If you rev the engine, or ease into it at about quarter throttle, you can make it to the 7,500RPM red line. I've checked everything I can think of, and everything the BGB can think of, including fuel systems, exhaust, ECU, MAF, and diagnostics. I have yet to check to see if the converter is plugged, or injectors, however I doubt it would be them. If it makes a difference, when the rebuild engine was installed, the old TVIS, MAF and electrical systems were used. Thanks for any help.

 

Is it an automatic or manual?

 

change your throttle sensor and that should help

 

Its a manual transmission. I checked the electrical connections and resistance from the throttle sensor, it checked out ok. Is there another way to see if its the sensor? They run around $100-150 for a new one.

 

Sorry I haven't updated the situation in a while. Done a lot to the car since my last post. I moved from Texas to New York, found out the cat and muffler were clogged along the way. Cleaned them out and the car accelerates better but still has the same issue. Cleaned an endless amount of exhaust and unburned gas out of the intake; thank you clogged cat. Checked every last vacuum hose and electrical connection, including replacing the slightly worn dizzy cap. Drove the car around for a while with the muffler off when I had it cleaned and noticed it made an odd sound. I consulted my father and he told me it sounds like the car is dropping a cylinder at 6,000. The last thing we can think of is maybe during the engine rebuild, either the timing belt or one of the cam shafts is a fuzz off? Any help or ideas would be great, thanks in advance.

 

Get one at a junk yard.

 

Alright, I could get one at a junkyard. But the car isn't having the type of trouble that would come from a faulty throttle sensor. If you rev the car in neutral, or ease into the peddle you can make it past the mark. Its only under heavy acceleration that the problem happens. Any other suggestions?

 

Could still be electical. My MAF want getting any power and the signs were it would try to kill the motor if I gave it to quick of acceleration. If I eased into it I could get it to redline no problem.

No much help or advice I can give you but it does definetly sounds electrical to me

 

I'll give it another look. We did adjust the spring inside the MAF to make the car run a little more rich, and when we did it helped the problem slightly. I'll play with it some more and see what happens.

 

Ide look into that MAF some for sure if youve tampered with it.

Good luck!