Sputtering and hesitating under boost?

[BOOSTJUNKIEGSX]

I have read many threads about the P0105 code that my car threw. Thinking this was the problems the symtoms were different where as everyone hesitated and sputtered at idle and low throttle whereas mine is fine at idle and comes on under boost like being held back sputtering. The code was cleared because a wire (believe pin 81) was disconnected (ORANGE) and then the light went away.. But the problem stayed??

Driving on the highway 5th gear doing 80mph 3200rpms the car can be driven fine with the accelorator at a steady position. if i give it more gas to pass someone the car sputters-hesitated like running on 1 cylinder barely passing anyone..But the car is fine between 0 - 2800 rpms?

Compressions fine
Boost leaks fine
New spark plugs..

 

[GVR4592]

Does it only do it in 5th gear? How much boost are you running? Can you post a datalog of the problem?

 

[BOOSTJUNKIEGSX]

Nope it does it in every gear. Like its drowning in fuel gerguling while boosted and when its spooling up it feels like its pulling a house. I dont have a data logger sorry- my friend just sold his logger with his car so until i invest i cannot say. Im doing a voltage test as we speak on the MAP. Any other questions please ask ill be back and forth by the computer. THANKS

Boost is at 19psi but i put it down to 10psi to see if it would be different and it does it then too!

 

[GVR4592]

Do you have 550's installed? What are you using to tune them if you do?

 

[BOOSTJUNKIEGSX]

Yes i do.DENSO 550`s. I have the zeitronix zt2 wideband but its pointless to use because i cant get a pull. I have a 95 gsx also and i pulled the MAP sensor(so called from ontop of intake manifold) and i also pulled the Power TR unit. The car is still the same!?!?

 

[GVR4592]

How are you compensating for the injectors?

 

[reeper]

I think you need to find a way to adjust your injectors, afcII would do the trick

 

[cc4ever]

You have new plugs, so I hope you gaped them to .28, and I hope you have some sort of fuel controller.

 

[BOOSTJUNKIEGSX]

Its crazy because this never happened. I had the car for 2 yrs and it gave me problems when i did my FMIC,and porting because i had no fuel pressure regulator with the 255...(giving the same sputtering). I have the S-AFC with settings tuned for the turbo and an aeromotive fpr. I also changed the MAF from my 95 thinking it may be that and it got better but its still missing under boost. I did a few logs with the wideband to see if i can get it to run goood and no matter what boost i go to it seems to stay at 10 to 14psi even maxing my hallman manual BC??

Having the fp 16g on the car about 2 weeks ago(on for 2yrs 21psi no prob) i recently installed a Turbonetics external wastegated 50 trim . Had it on for a week and took it off to go back to my proven setup until i could get motor work done. Took turbo off put this one back on and now all this.. could it be lack of oil - coolant to turbo ect?

Suggestion??When turbo was back on i could floor it and it would go to about 2500rpm and stutter like a shutter box to launch.. This was caused by a wire on the AFC that was probably broke by my foot and wasnt connected! Now the problem is under boost so im thinking it has to do with wiring to the ecu. Could any of those wires create this if not properly installed or broke? Im going to rewire my afc and wideband so i know its 100% correct.

THANKS GUYS!

 

[UnderPrssureDSM]

Have you checked the plug wires? I had the same thing happen when my Magnacor's took a dump.

 

[BOOSTJUNKIEGSX]

Thats a great point because when i last had the car tuned by the shop they said i would need new wires asap and i never changed them.. That was 1yr ago. Well im off to the back yard to hit up the 95 gsx and ill post any difference within the hr! thanks!

 

[UnderPrssureDSM]

Good luck with that. The Magnacor's developed a small tear where the wire met the boot, and badness ensued. That's why I switched to NGK's. No problems since.

 

[BOOSTJUNKIEGSX]

Appreciate it. What were you`re symptoms..

 

[UnderPrssureDSM]

Everything you described.

 

[BOOSTJUNKIEGSX]

Well sad to say but i installed new wires, coil, and rewired my AFC to make sure everything is correct and the problem is the same.. No check engine light. I dont know wha else to try..

Pin # 85 - Barometric pressure sensor (orange)- There is a adjustable switch that it is soddered to it. I have no idea what it is for and if i turn the knob at idle the rpms will notice a change but still be normal. If i put the switch to the middle the rpms will go to 0 barely idling and sometimes dieng. Could i eliminate this switch having the line normal? What is it for?

To sum it up again the car idles fine, rev`s to 6g normal with bov, sounds healthy but when boosted there is sputtering, hesitation and a miss..

Could it be a burnt valve?

Changed/checked so far:

No Boostleaks
Compressions 150 across board
Afc rewire
Power tr unit
Map sensor
Coil
Wires
MAF from my 95 gsx
Plugs gapped to .28

 

[taloneagle]

i am haveing the same problem's right now if you figure it out ### let me know....

 

[BOOSTJUNKIEGSX]

Base TIMING is fine at 5..

No Boostleaks
Compressions 150 across board
Afc rewired to ensure correct positions
Power tr unit changed
Map sensor changed
Coil changed
Wires changed
MAF from my 95 gsx
Plugs gapped to .28

What else is there? - ECU -

From the AFC the two wires Orange and pink (Air flow in & air flow out) tapping into the airflow signal were unconnected and i drove the car ..Do you think this damaged anything else.. The car ran like it was pulling a house then got worse to a surging problem when throttle was applied at idle. Wire was connected like stated above and surging at idle when throttled went away leaving the problem when BOOSTING... Could this of damaged something..

 

[BOOSTJUNKIEGSX]

For anyone with the same problem the culprit was my Barometric sensor. Once that was fixed the car was able to boost and then threw a check engine light for random missfire which lead to bad plugs and wires. Holds 21psi just fine!