This is either 2 related problems or just one big problem, not sure which. i have a 1990 gtu n/a. Around no specific rpm the engine kind of hesitates and the car wont really go anywhere (ive had it happen at 3k all the way to 6.5k rpm) and wont stop hesitating until i let off and upshift. recently it seems to have evolved to completely losing power sometimes and not resuming moving forward as long as my foot is still on the gas, as soon as i let up and upshift, the engine is able to move the car foward again. this seems to happen a lot more so within a half hour of the car being started. anyone ever heard of this problem or a similar one before?

 

My 90GTU used to hesitate really bad during hard left turns.



One suggestion that you might consider is to do some grounding.



Run a good heavy guage wire from the engine to a good frame ground point. I personally have a 1 guage wire running from a tranny bell housing bolt to the frame.



Also run a good ground from the fuse block under the hood to the frame. Then do the same with the ecu. Run a wire from the ECU box to the frame as well. The ECU is under a protective plate under the carpet on passanger side of the car.



That would be where I would start.



This is of course after you have done some of the basics like a tune up (4 new spark plugs and wires) and change the fuel filter.





Good luck!

 

Did you check the coils per FSM?

 

yep, checked all the obvious stuff and i had ran a ground from the boost controller on the passenger side strut bar per a common post i had found about hesitations around 4k, i give up though, im bringin it to mazda next tues, they'll hopefully find it in an hour

 

run a compression check, my 1st gen (was a GSL-SE) did something similar and the rear rotor had pretty low compression

 

you know...

i was having the exact same problem in my 88 TII before.

i checked everything, and all seemed fine.



i thought i had figured it out..but this hesitation would seem to occur whenever the car felt like it. my compression was still normal and the car should've been running well.



for my car, it was the TPS. after replacing it, i never experienced the hesitation ever again. it's a good feeling, getting rid of pesky annoyances.

 

that's what i also wanted to suggest but forgot what it was i wanted to say

 

ok i have a question if it is a GTU it should npt have a boost controller, Should it????????? My 88t2 does the same thing I think it is the Fuel Cut kicking in. An FCD should solve the problem. It could aslo be a bad fuel pump. It may not be able to keep up with demand a higher RPM with your foot on the go pedel,

 

I am looking at a car with the same problem, the injectors have all been relpaced so here is the newb question... What is a TPS or FCD I did a search and I got nothing.

Thanks

 

TPS = throttle postition sensor, FCD = Fuel cut defencer.