4k-5k RPM hesitation

gpmarzan

New member
Whats up guys. I havent been here in a while as I sold my alltrac to bloodmoney (Chris) and bought a 92 MR2T.
My question pertains to the deuce. Having the same good ol 3sgte, I figure you guys can help me out.

In short, at WOT the car seems to hesitate at around 4k to 5k like timing is being pulled. Once it passes 5k, you can feel the power come back, starting to pull hard again. Doesnt matter if the car is set at low boost, 9psi, or high boost at 15psi- its the same condition. So far here are the things I have done and what the car has:

-Ebay 3" downpipe (came with the car)
-3" exhaust system
-50 trim compressor ct26 turbo
-upgrade side mount intercooler
-checked for boost leak- none found but will recheck again
-replaced ignition coil- no change
-checked static timing- appears ok but i will double check
-checked dynamic timing- set at 10deg btc
-replaced TPS and adjusted to spec- no change
-fixed clogged egr system
-checked T-VIS- working properly
-new plugs (bkr7e)
-new plug wires, cap, and rotor
-new O2 sensor
-compression is good

I cant hook up my wideband as the bung on the ebay downpipe is in a wrong location making the sensor contact coolant pipe. Only 3 things I could think of now is the AFM, ECU or the timing might be off. What do you guys think?
 

gpmarzan

New member
88st165":2kk5je4w said:
Does it do the same thing at part throttle like around 3/4?
Now that you have mentioned this...NO it does not do it when at 3/4 throttle or anywhere below WOT to that matter. I know my alltrac has this "faster at 3/4 throttle" issue but it wasnt like this where it hesitates only at that certain RPM range. Any thoughts?
 

88st165

New member
Yea I think knock is the culprit. My car used to do the same with the stock 165 intercooler and 15psi. I added WI and the phenomenon went away whenever the WI was activated. Came back when it was off.
 

gpmarzan

New member
88st165":1bel56lz said:
Yea I think knock is the culprit. My car used to do the same with the stock 165 intercooler and 15psi. I added WI and the phenomenon went away whenever the WI was activated. Came back when it was off.
Hmm. Although it does it even when at low boost (around 9psi)
 

Simba

New member
Probably AFM or cam timing. If you're getting into enough knock to feel timing come out at 9psi and relatively low revs, something very weird is going on.

The ECU will not dump timing back in as quickly as you're describing, either.
 

Mafix

New member
have you check the fuel pressure? and the regulator? similar issues with avi's 165 and the culprit was the regulator
 

bloodMoney

Active member
I've got a generic FPR if you want it Patrick. I can't remember if it has a gauge on it, but if you want it, let me know.
 

88gt4DE

Active member
Mine too and had rusty gas tank clogging filter ... 2nd Mafix recommendation. pain in the ass to hook up but fuel pressure tester and tape it to the glass and watch reading in trouble zone .... mine dropped to almost 15 psi when it got really bad .... should be up in the 30's range ...
 

gpmarzan

New member
bloodMoney":3j2uvv78 said:
I've got a generic FPR if you want it Patrick. I can't remember if it has a gauge on it, but if you want it, let me know.
Dude its worth a shot, pass it on over here if you have it. :D

btw, I love coming on this forum and seeing my sig. The st165 just look so damn good.
 

gpmarzan

New member
Acquired another oem regulator from someone on mr2oc forum. Waiting for that to come in to try it out.
Its getting really annoying. In 2nd gear even at 8-9 psi, if I step on it anywhere below WOT it hauls pretty good. If I do the same at WOT in the same gear, you feel the car not pull as hard, specially at around 4k RPM where you really feel it pull back. Still no codes.
 

timco

New member
I'm having this same issue, have an 88 all trac with an st205 3sgte swapped in, havent had time to check into yet as Im replacing all the struts/shocks/rotors(bla bla) I'll be looking more in depth when I get a chance though. Running only 8 psi atm.
kris
 
Top