HELP: Resistance-Feels like fuel cut when i let off the gas, Whats the cause? Options

[racer4street]

Ok, I will try to explain the issue the best i can. I have researched over and over again and everyone has there own advice and feedback but nothing from anyone who really knows the Celica's so hopefully i'll have better luck here.

First off just to give info on what im driving. I am driving a 1994 Celica GT 5sfe with the 3sgte turbo setup (CT26) tuned by an safc 2 at 8psi.


Ok, when i drive the car (doesn't really matter what gear or how fast) and i let off the gas the car will slightly jump back like the fuel has been cut????? and when i start to accelerate as soon as i give it some gas it will slightly jump forward like the fuel has been let back on??? after that it will drive fine. I drive it everday. WEIRD ISSUE!

I have no idea why its doing this please help me. The car starts and idles fine and does not throw any check engine lights other than one for the EGR valve but the light hasn't come back on in a week or so since i cleaned all the carbon buildup out of the ERG valve. Also i have changed the spark plugs, cleaned all IC piping, checked all vac lines, had it street tunned, cleaned injectores (460cc).

Possibly a bad o2 sensor? When i let off the gas my A/F gauge goes straight to LEAN. Optimum while driving. Also the car does have liquid injection but i don't think that's the problem but who knows.

If anyone has any idea of whats causing my problem please let me know. Thank you!

[domyz]

Check for stored codes...

First clean the Throttle body with TB cleaner. Make sure that the after-compressor piping is properly sealed.


If it doesn't work and you are running an AFM setup (Ignore this if you are running a MAP sensor setup):
Maybe you could try to put you BOV into recirculation and/or clean it.

If it doesn't work and you are running an AFM setup (Ignore this if you are running a MAP sensor setup):
try to clean your Air flow meter mechanism with electrical cleaner or mass air flow cleaner, and adjust to OEM setting the bypass screw
it seems to be the mechanism that react too slowly for your throttle

If that doesn't works (Ignore this if you are running a MAP sensor setup):
Try opening it SLOWLY and DO NOT UNSCREW THE SCREWS NEAREST TO THE AIR FLOW METER, you will disconnect the electric mechanism and possibly break your AFM.
Unscrew the connector screws (good ones) and open it removing the rubber-like gasket. Clean the black track with electrical cleaner. Reseal that with a good Paste-like gasket that you will find in every good Hardware store.

If that doesn't works, read the other posts hahaha


AH!! Maybe a wrong TPS sensor, so many thing could create a problem like yours...

This post has been edited by domyz: Sep 25, 2009 - 8:40 PM

[Detatch]

Ok, I will try to explain the issue the best i can. I have researched over and over again and everyone has there own advice and feedback but nothing from anyone who really knows the Celica's so hopefully i'll have better luck here.

First off just to give info on what im driving. I am driving a 1994 Celica GT 5sfe with the 3sgte turbo setup (CT26) tuned by an safc 2 at 8psi.


Ok, when i drive the car (doesn't really matter what gear or how fast) and i let off the gas the car will slightly jump back like the fuel has been cut????? and when i start to accelerate as soon as i give it some gas it will slightly jump forward like the fuel has been let back on??? after that it will drive fine. I drive it everday. WEIRD ISSUE!

I have no idea why its doing this please help me. The car starts and idles fine and does not throw any check engine lights other than one for the EGR valve but the light hasn't come back on in a week or so since i cleaned all the carbon buildup out of the ERG valve. Also i have changed the spark plugs, cleaned all IC piping, checked all vac lines, had it street tunned, cleaned injectores (460cc).

Possibly a bad o2 sensor? When i let off the gas my A/F gauge goes straight to LEAN. Optimum while driving. Also the car does have liquid injection but i don't think that's the problem but who knows.

If anyone has any idea of whats causing my problem please let me know. Thank you!

i'm thinking it's because he's running a turbo that'd designed to run off of 550cc injectors with 460cc injectors... other issues could be his fuel pump may be wearing out, or the ECU may have an improper tune... more than likely it's that the injectors..

take it to a shop and have it checked.....

[supershannon77]

You don't need a safc. Who did your wiring harness for the 3sgte? The factory 3sgte ecu can read boost so no worries esp at 8 psi.