Author Topic: still battling........studder, hesitation, fuel cut? help please  (Read 1676 times)

Offline GlenMartin

  • Hero Member
  • *****
  • Posts: 1467
well after doing a 16g install and a ton of other things i am still having the same old problem. get to about 4500 rpm, and the car just dies and pops, and sputters. i have 100% no boost leaks. i had my throttle body rebuilt, the grommets for the injectors replaced, all the piping re done. confirmed it is not leaking with a boost leak tester. stock injectors, 255 walbro, 16g, stock maf. interesting fact. if i hook up my gm maf, and translator which is still wired into the car, it runs fine. idles fine, goes well under wot. however the with the stock maf. now this is my second one. it will not rev, or build boost under wot. well it builds some but not much. if i go half throttle it will respond better. it will do this at idle. not just under load.  i got new plug wires, gapped the plugs. checked a ton of sensors, and shit, replaced a bunch. fiacv, iacv. when i put everything back together i suspected boost leak. no boost leak. suspected i didn't set up the tps properly. i have checked it at least ten times, and to the best of my knowledge it is done correctly. (did tons of research online for the correct steps) no vacuum leaks. am i hitting fuel cut? at idle? no codes to speak of. i am really starting to get stumped. normally i would just hook up the gm maft, and forget about it, but i am going to be selling the car, and if someone who knows nothing about dsms's buys it, i would feel pretty bad if something went wrong and they had to take it to the stealership. plus i don't like it when i cant figure something out. readings on my wideband are all good. except at idle with the stock maf, it runs lean, and with the gm maf it runs rich. any ideas? i think i am covering everything. i did a ton of searches online, i checked every suggestion online pretty much. there was really only two. fuel cut and BOOST LEAK TEST.

thank you in advance.
ahah we both have a good side. lets sue each other!

Offline Kevin Altoe

  • Full Member
  • ***
  • Posts: 188
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #1 on: March 31, 2014, 08:47:45 pm »
Do you have some sort of logging device?  A log might help diagnose the problem.  Any tuning devices.  Is it a known good MAF?
1995 Eagle Talon Tsi AWD

Offline Ryan Singh

  • Hero Member
  • *****
  • Posts: 2579
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #2 on: March 31, 2014, 08:55:22 pm »
Fuel filter?
2001 Altezza RS200
1996 TSi AWD - In hibernation

Offline GlenMartin

  • Hero Member
  • *****
  • Posts: 1467
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #3 on: March 31, 2014, 08:56:32 pm »
Its just stock ecu so no tuning capability. As for logging I have evoscan but will have to borrow the gfs laptop, mine got smashed on my last logging session. Yes I threw it. The only way I was tuning before is with my wideband and gm maft. Well the old maf was known to be good, but then this started to happen, so I sourced another one said to be working. Same result. Another thing I should mention is that it is also a brand new knock sensor.
ahah we both have a good side. lets sue each other!

Offline GlenMartin

  • Hero Member
  • *****
  • Posts: 1467
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #4 on: March 31, 2014, 09:02:38 pm »
Fuel filter?

My air fuel ratio is good, could that still be a problem? I mean I should change it, its just such a fuck bitch.
ahah we both have a good side. lets sue each other!

Offline Ryan Singh

  • Hero Member
  • *****
  • Posts: 2579
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #5 on: March 31, 2014, 09:21:44 pm »
Fuel filter?

My air fuel ratio is good, could that still be a problem? I mean I should change it, its just such a fuck bitch.

The reason I mentioned it is because I had some serious sputtering issues way back when, a fuel filter change as well as plug wires fixed it. Can't say for sure that it will help but it's cheap if you do it yourself and worth a shot.
2001 Altezza RS200
1996 TSi AWD - In hibernation

Offline Kevin Altoe

  • Full Member
  • ***
  • Posts: 188
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #6 on: March 31, 2014, 09:40:57 pm »
I feel like if it ran normal with the GM MAF installed it has to be an issue with the stock MAF as the only factor being changed.  Doesn't make sense for it to be anything else.  I think logging it will be the only way of giving you a clue to what is really going on.
1995 Eagle Talon Tsi AWD

Offline GlenMartin

  • Hero Member
  • *****
  • Posts: 1467
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #7 on: March 31, 2014, 10:33:47 pm »
Fuel filter?

My air fuel ratio is good, could that still be a problem? I mean I should change it, its just such a fuck bitch.

The reason I mentioned it is because I had some serious sputtering issues way back when, a fuel filter change as well as plug wires fixed it. Can't say for sure that it will help but it's cheap if you do it yourself and worth a shot.


Ya your right it is I just cannot due mt fuel filter I have tried its impossible without another person helping and a lift. Worst design ever.
ahah we both have a good side. lets sue each other!

Offline GlenMartin

  • Hero Member
  • *****
  • Posts: 1467
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #8 on: March 31, 2014, 10:37:28 pm »
I feel like if it ran normal with the GM MAF installed it has to be an issue with the stock MAF as the only factor being changed.  Doesn't make sense for it to be anything else.  I think logging it will be the only way of giving you a clue to what is really going on.

Ya I think your right it doesn't make sense, but two mafs being mad is kind of weird. It happens I know but. I wonder is there is a resistance test I can do on it to check them.

What heat range plugs do you guys run?
ahah we both have a good side. lets sue each other!

Offline CamWeiss

  • Hero Member
  • *****
  • Posts: 1747
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #9 on: March 31, 2014, 11:07:58 pm »
Sounds like fuel cut to me, especially given you're running a 16G. The stock MAF is barely enough to deal with the stock turbo, never mind the increased flow of the 16.

Get some management and some injectors in there...
Objects in mirrors appear to be losing.

'92 6/4
'86 325e
'72 240z
'76 R75/6
'07 KTM 640 ADV

Offline Rob Armstrong

  • Hero Member
  • *****
  • Posts: 2131
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #10 on: April 01, 2014, 12:18:00 am »
How much boost you running?
Brp7es or something like that for plugs.
I would put some 550's in at least.

Offline Jason Harwood

  • Hero Member
  • *****
  • Posts: 2507
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #11 on: April 01, 2014, 07:15:33 am »
I had a 16G on stock injectors and the stock MAF. I did not have this type of issue at all.
I had a FMIC and a cat back (stock down pipe) as well. No other mods than that.

Stock boost level as well.

My car ran perfectly fine. So i'd say a MAF should be able to handle the 16G just fine.
It is possible the MAF is bad, you are saying it runs fine with the GM MAF.

You should really be getting it tuned!
88' MX6 Turbo - 14.2 @ 97.51MPH
94' MX6 V6 - 13.9 @ 96.7MPH
93' Civic Turbo - 14.7 @ 90MPH (bad tune)
90' Civic SI - Auto-X Machine
97' Eclipse GSX 13.6 @ 105MPH
96' Jeep Grand Cherokee Laredo
97' Acura EL 14.5 @ 98MPH
'02 Lexus IS300 15.125 @ 91MPH
97' CR-V Winter Beater.
04' WRB WRX STI

Offline Eddie ly

  • Full Member
  • ***
  • Posts: 191
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #12 on: April 01, 2014, 08:02:04 am »
I had a 16G on stock injectors and the stock MAF. I did not have this type of issue at all.
I had a FMIC and a cat back (stock down pipe) as well. No other mods than that.

Stock boost level as well.

My car ran perfectly fine. So i'd say a MAF should be able to handle the 16G just fine.
It is possible the MAF is bad, you are saying it runs fine with the GM MAF.

You should really be getting it tuned!

+1
GM maf is lest restrictive and it ran fine, fuel cut shouldn't be an issue with the stock maf unless boost is raised. Check the connector/wires on the stock maf for Loose pins and corrosion ect...

Offline GlenMartin

  • Hero Member
  • *****
  • Posts: 1467
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #13 on: April 01, 2014, 06:58:43 pm »
ya i should post up my mods in more detail. 2.5" down pipe to 3" all the way back to a muffler. no cat. ported 16g, fmic, short route piping. hardly a mod, but thought i should mention it. walbro 255lph. the gm maf is also wired in, i can swap it in and out in 5 minutes. stock injectors. i have some 785cc on the way. thats pretty much it. i have a fpr i am going to install when i do the injectors. i mean once i do the injectors i am going to have to use the gm maf anyway, but it still really baffles. me. i mean i just cant see it hitting fuel cut just sitting there reving it no load on the engine. i checked the resistance of the tps, and it checked out to be functioning normally. i looked online briefly and there is a resistance check i can do on the maf, but it requires i cool it then heat it. maybe someone else can confirm if there is another way. i wont really have to much time during this week to work on the car, but on the weekend i am free. so any ideas would be great. i will try and log it this weekend.

i am running stock boost for a 16g. so like 14-16 pounds. when i had the gm maf in there it would creep up to 18 then come back down. at idle though, or rather reving it in neutral it barely gets to 1 psi at most.

any other ideas are welcome. i am going to get new plugs just to rule it out.
ahah we both have a good side. lets sue each other!

Offline daniel Dee

  • Hero Member
  • *****
  • Posts: 1881
  • Fully drivable
Re: still battling........studder, hesitation, fuel cut? help please
« Reply #14 on: April 01, 2014, 11:21:58 pm »
I say MAF issue.  Ran Evo3_16g  setup 550 inj /2g mas/3inch all the way......255 walbro ....stock ECU no problem at all
92 AWD TSI 5spd<br />Built motor ,AEM EMS, Arc2 cdi 1050cc&1000cc Staged injectors Billet S366 T4,top mount manifold.666 AWHP@39psi (RG Dyno 2010). New mods E85, BF cams, 72mm turbo, 70mm throttle body />90 TSI (gone), 95 TSI 5 spd sold, 93 Mazda 5sp(sold), 97 Acura 5spd Vtec 99 Audi A4 quad 5sp 2018 Civicturbo 6sp ktuner