Hesitation Off and off boost and popping @WOT

[95 GST EVOIII]

Hey guys,
I have 95 GS_T w/16g turbo,cone air filter and new greddy blow of that is recircuting.
my problem is when i take off with a little throttle kinda hesitates,but if you give it 3rd throttle then the car boost and takes off with sputtering and if i go beyond that the car boost then falls on its face and backfires and pops in intake.any suggestions.i am thinkin its tps ### of the flat spots in it.please let know and thanks.

 

[blackGSX2g]

How old are your plugs? You might want to throw in some new NGKs gapped at .028" and check your wires.

A faulty TPS sensor should not cause your symptoms. I've ran with the sensor unplugged and have never had any sputtering problems.

 

[95 GST EVOIII]

i just bought the car and am new to all these problems that come with owning a dsm.i will check and or change the spark plugs/wires and get back with an update-thanks alot

 

[mavisky]

Sounds like fouled plugs.

 

[95 GST EVOIII]

Ok guys i changed the plugs and wires.They needing changing because the prior owner had Bosch platimun's annd of brand wires which 2 of tham were arching near the plugs.So i put in NGK wires 8100 and NGK 7131 plugs gapped at .028 and the problem still exist.
What do you guys suggest?

 

[95 GST EVOIII]

Well,the car doesn't run any better with the new plugs and wires.I checked for boost leaks and found none. Found out the o2 sensor was spliced and from a 1g.Would that be problem?I am going to check sensors next.Any suggestion fellas?thank you

 

[TalonESIT]

what are you boostin? any fuel mods? like i was talking about in another post where my car was backfiring like crazy but it was due to a lean mixture at wot, or close enough to wot

 

[95 GST EVOIII]

My car is all stock except for a turbo upgrade,cone air filter,and Greddy RS BOV.Am boosting at 10psi.

 

[TalonESIT]

? to 4g owners for this guy, by upgrading to a bigger turbo does he need to increase his fp to compensate for the increase in air? or will the pcm do that for him? cause if it doesn't then it does sound pretty similar to my problem

 

[blackGSX2g]

? to 4g owners for this guy, by upgrading to a bigger turbo does he need to increase his fp to compensate for the increase in air? or will the pcm do that for him? cause if it doesn't then it does sound pretty similar to my problem

His FPR should raise fuel pressure on a 1:1 ration with boost pressure until the limit of the fuel system is reached. The stock fuel system will hold 10psi on an evo III with no problems.

Are you getting any check engine lights at all?

 

[95 GST EVOIII]

No check engine lights.I did speak to the prior owner again and he said that the car ran great after installing the turbo.Problems came approximately 1,000 miles after.he thought it was a boost leak,but can't seem to find any.what is a pcm?Thank you guys for giving input.Please keep it coming.

 

[95 GST EVOIII]

checked my coil and found the reading on primary side to be 42.155 for both give or take a few and on the secondary side to be 14k ohms for both which is within specifications.what else do suggest i do?

 

[95 GST EVOIII]

hey guys,i check sensors out and found nothing to be wrong.i did change my spark plugs back to the bosch platinum and the car runs better than when i put the new ngk's in.what's up with that?i have been reading in the forums that the correct plugs are ngk.so why would my car run better with the platinums?what could be my problem?any advice?

 

[GVR4592]

Platinums are bad for turbocharged engines. They can increase the chance of detonation.

How are you checking for boost leaks?

 

[forGEE63]

At 10 P.S.I. your car should run fine, but it is recomended to upgrade either your fuel pump or fuel injectors when adding a larger turbocharger. I have had a bad o2 sensor on my 95 Tsi and at an idle the car wanted to bog out. So it is possible that you have the same problem.

 

[95 GST EVOIII]

i am using the one made of pvc and the tire type air valve.why do platinum plugs cause detonation?thanks

 

[95 GST EVOIII]

I found the problem.the prior owner had vacuum line plugged going to the turbo intercooler inlet on top.so i ran that to the t going to wastegate and the hose i removed from was to to go the air filter according to the repair manuel.now the car boost to 15 psi and i was wondering if it is because of the greddy BOV screw turned to far in or is that the way Evo iii 16g turbo boost cause i dont have a Manuel boost controller.also the car still has hesitation at low rpm but is fine at wot.can anybody give me some advise as to what is causing the hesitation.i cleaned the airflow meter with brake cleaner.it helped a little but like i hoped.
thanks