1.8t AWP weird "lagging / surge / stutter" boost / throttle feel ?

[pl4life52]

im going to check the valve today. Also any way of checking the fuel pump before i spend money and find out its not needed later on?

What about fuel filter? Would it cause anything, im going to change it regardless but just wondering

http://www.ebay.com/itm/Volkswagen-J...d2204c&vxp=mtr

is this the fuel pump i need?

[805 GTI]

im going to check the valve today. Also any way of checking the fuel pump before i spend money and find out its not needed later on?

What about fuel filter? Would it cause anything, im going to change it regardless but just wondering

http://www.ebay.com/itm/Volkswagen-J...d2204c&vxp=mtr

is this the fuel pump i need?

you can ohm the fuel pump with a fluke/ volt meter.... im taking a fuel systems class and i believe the instructor said it should be about 6 ohms.... my friend did it to his car and it was at 4 ohms. It runs fine but its on its way out. and u can change the fuel filter but if the pump is ohming low then it might go out pretty soon.

[805 GTI]

and yes a clogged fuel filter willl restrict the gas going through the fuel pump so the pump will have to work harder/drawing more amperage to keep the fuel flowing... this in time will cause the fuel pump to fail

[pl4life52]

thanks guys I bought the filter yesterday but got real lazy for this ten minute job and i will also test the fuel pump today. The link that I posted would that be what I need?

[805 GTI]

thanks guys I bought the filter yesterday but got real lazy for this ten minute job and i will also test the fuel pump today. The link that I posted would that be what I need?

the ohms will be differnet with every car manufacturer... my friends was a toyota so i dont know about VW's

[AEGTI3913]

Quick follow up on the original issue posted:

Went to the shop that did the APR tune. We drove the car, and he said that it seemed to be a minor boost fluctuation issue which only presents itself when you are slightly adjusting throttle somewhere in the mid RPM band. We also noted that the dog bone mount was junk at 95,000 miles (some on the track) and new bushings should help remove some of the jerking back and forth from on/off throttle/boost. So friday a new dog bone is going in.

I think his take-home message was that this may just be a product of the higher boost (17psi vs 10psi) in the tune and that there may be some degree of this to deal with if I want to run a tune. If I switch back to the stock map, the issue is gone. Keep in mind that the issue did occasionally present itself BEFORE I ever got the tune.

Does anyone know if this is a common (maybe not discussed much) problem for doing stage 1 tunes? I've been told that APR was some of the smoother tunes, but maybe it's an APR issue?

[pl4life52]

It rained here today so couldn't do it. But I was driving today and it did it twice from stop to stepping on it hard it sound like someone making a fart noise lol didn't seem to pull strong I guess like sputtering. Fuel filter replacement and checking diverter valve and fuel pump is a must tomorrow. Hopefully fuel filter will help a bit its just feels like boost isn't holding. I also noticed(new to tubing) when I'm doing sixty a little more and floor it boost jumps to fifteen but slowly drops even if I keep foot on the pedal.

Thanks for the help guys

[AlwayzDubbin]

I've had the same issue with my 1.8T with APR software. I've done everything above to see if it would fix the problem and nothing has worked. I'm 100% sure it's the tune since its the only thing I did before this started happening. I'm working on getting a new ECU since the shop that did my tune lost my stock program. I heard unitronic is WAY better..

[Slimjimmn]

you can ohm the fuel pump with a fluke/ volt meter.... im taking a fuel systems class and i believe the instructor said it should be about 6 ohms.... my friend did it to his car and it was at 4 ohms. It runs fine but its on its way out. and u can change the fuel filter but if the pump is ohming low then it might go out pretty soon.

From fuel pumps I have tested over the years with resistance readings:

ofl (open) - open motor windings, will not start

1-2 ohm - normal reading new or proper functioning pump

168 ohm - high resistance, weak pump, poor pump operation



the only "proper" way to test a pump is to put a scope on the b+ wire when the pump is operating. If it has high amperage draw the pump is going out (but resistance test will show high resistance) It will also show if the pump has field winding issues by showing a wavy pattern.

and

[pl4life52]

sooo i was thinking not sure if this would make a difference or not, but I replaced stock intake with the DIY cone filter. I was driving today and the things that make the car feel like this didnt happen prior to the air filter change not sure if its a coincidence or not but I was just wondering.

Thanks

[Slimjimmn]

Cone filter on a vw maf does not work.

Neuspeed pflow- nope
EIP cone - nope
ITG - nope
Ebay ram air - nope

42dd velocity stack for tt- yup

Your maf can not properly read air coming in due to it being all jumbled from that filter.
Look at the stock airbox. It has a velocity stack on the inlet to the MAF sensor.

[henryhendrixx]

I have the exact same problem. My '03 GTi has 130k miles on it and we checked under the hood and found the PCV Line was like swiss cheese with all the cracks and whatnot. I assume that's what the problem is. I have a boost gauge and whenever the drop in power happens it's on cold starts and when my foot is in one place on the pedal. The gauge will show a drop anywhere from 3-7psi and ever since I put a cone air filter on it I can hear the air "whoosing" out like I just let off the gas. The replacement line will be here tomorrow and while I'm at it I'm going to clean the N75 valve and EGR valve, I heard those can get dirty and I don't much see the harm in it. Hopefully the line will solve my problem though.

[pl4life52]

Cone filter on a vw maf does not work.

Neuspeed pflow- nope
EIP cone - nope
ITG - nope
Ebay ram air - nope

42dd velocity stack for tt- yup

Your maf can not properly read air coming in due to it being all jumbled from that filter.
Look at the stock airbox. It has a velocity stack on the inlet to the MAF sensor.

Well WTF man lol why didnt you tell me this before lol. So if this isnt a good idea for our car why do we have a DIY for it other then sounding good and messing with the car? It wouldnt matter if I reset the computer with this intake on correct? I should just put the stock one on?

[Slimjimmn]

cold air intakes are ok. Or usually the intakes with a pipe off the maf sensor like 6" is ok.
Its just the cone directly on the maf jumbles the air when entering the maf and it cant read correctly.

[Kushdaiin]

Have the same problem as the OP except I'm still OEM tune. For me, it happens 80% of the time when under 75% to 100% open throttle when I let off even a bit. Also, if I don't let off the throttle, this problem doesn't occur. One small difference is that my throttle comes back almost as quickly as it was lost. I plan on replacing my N75 soon and the on/off nature of my problem seems like it could correlate to a solenoid in the vacuum system (i.e. N75). Will report back when it is replaced.

[die65cast]

I might have missed it but did you check your n75? Is the boost fluttering? If you have a boost gauge bring it to wide open throttle in say, 3rd gear and build full bost and see if the needle flutters around. That tends to be n75 related. I was having the same issue when my stock n75 started ****ting out on me. Fluttering under heavy throttle and surging/dropping power under low throttle when the car was still warming up. I just so happened to have an extra ecs race valve lying around and swapped it out and it ran like a champ. Hope this helps.

[pl4life52]

ok my intake is about8 inches and I found out one of my breather tubes busted. so far its alot better no popping or stuttering, i gues you guys can check tubes just to make sure?

[805 GTI]

mine used to do that too, but then i started driving it hard, and now it seems like the problem is gone.... i dont know how that happened, but it drives alot better.... i bought the car off some guy about a month ago, i started driving it hard and the problem slowly went away.... wierd

[AEGTI3913]

Update to original post:

The throttle body was a bit crud-ed up and so it was cleaned out and then reset. Toe-in acceleration is improved and smoother.

Turns out the DV was original even though it was the newer TT type. Replaced it with a new one. OEM.

Dogbone was orignal with 95k miles, so replaced, also OEM (for now). This helps with the issue I'm having as I think the motor is just moving less when this boost drop occurs, and so I think I just feel it less.

BUT. The issue is still there. I'm now told by the shop that chipped it, that this is a subtle boost related symptom, maybe because of the tune, and not to worry about it. Basically, this is a price to pay for the added power of a tune with these motors.

I'm wondering why I've never heard about this issue before. I'm considering calling APR and seeing what they say it might be. I feel like I need a real turbo expert that understands in details all the things going on in the motor, and then actually know what's causing this issue.

If it is simply a symptom of running higher boost, then I guess I'm left wondering if I want to go back to stock, even though it won't be as fast.

[pl4life52]

i changed the fuel filter and fixed the hose things seem better so hopefully it stays but im going to clean TB, got any tips?

[Brandon_Schulze]

Did Someone Say Seafoam?

[broadymcbrick]

I know i dont have any street cred on here butttt ive had they exact same thing happening to me ...i pulled the plug on my maf and it cleard up alot of the problems ....may be worth you time to unplug the maf and see if it helps

[pl4life52]

MAF cleaning tomorrow and sea foam will be done when i change oil

[slakr7555]

may be a different issue but on mine (AWW) i had tons of little vac leaks in all the bs under the intake causing the pcv system to fill up with oily snot which choked the whole system. mite not help ur issue but get rid of all that bs. pcv, sai, n249, n112, evap, etc. waste of space and helped me out alot once they were out of the picture. makes problem diagnosis much easier now too. do everything thats been said so far but also look into that. gl

[AEGTI3913]

I know i dont have any street cred on here butttt ive had they exact same thing happening to me ...i pulled the plug on my maf and it cleard up alot of the problems ....may be worth you time to unplug the maf and see if it helps

Meaning you just got rid of your MAF??? You got a new one? What do you mean exactly by "pulled the plug"?

[AEGTI3913]

may be a different issue but on mine (AWW) i had tons of little vac leaks in all the bs under the intake causing the pcv system to fill up with oily snot which choked the whole system. mite not help ur issue but get rid of all that bs. pcv, sai, n249, n112, evap, etc. waste of space and helped me out alot once they were out of the picture. makes problem diagnosis much easier now too. do everything thats been said so far but also look into that. gl

And you just decided to throw this stuff out? I'm confused by this post too. lol. "Ah, I'll just start grabbing parts under the hood and toss em out. Should run better now.."

[AEGTI3913]

If anyone is still interested, I decided to go back to the stock tune and return the ARP 93 file. At least for now. Never thought I'd do that, but there ya go.

I might try GIAC or Uni as I've heard good things about them, but want to get more specifics on what the tune actually is. I now have a better understanding of what the APR tune actually does.

I might try to get some answers on what causes the problem I was having at higher boost levels, and see if I can fix them, regardless of the tune.. but for now, the car runs great, just stuck at stock levels.

[slakr7555]

And you just decided to throw this stuff out? I'm confused by this post too. lol. "Ah, I'll just start grabbing parts under the hood and toss em out. Should run better now.."

actually now that i finally got all the parts i needed and the delete is done, it runs perfect. theres a diy on what do remove and how to remove it and for the most part its pretty easy. urotuning sells the kit with everything you need for around $200. i was amazed at the amount of tiny bs little hoses and valves and crap that i removed. now my vac and pcv system is simple and straight forward. im not gonna throw everything away tho. the combivalve and sai pump are extremely expensive parts and im gonna make someones day and sell em cheaps to recoup the money i spent on the delete. im not saying follow my lead, but it worked wonders for me.

[Slimjimmn]

I deleted my pcv system and the car runs and idles to much better.

[shnitzeltime]

hey guys i got a mark 3 gti with stock 2.0 i want to turbo it and boost it it already has supporting mods like cold air and nos and i raced a stock neon the other day and won i think my car would destroy with 500whp what do u guys think?

[Slimjimmn]

hey guys i got a mark 3 gti with stock 2.0 i want to turbo it and boost it it already has supporting mods like cold air and nos and i raced a stock neon the other day and won i think my car would destroy with 500whp what do u guys think?

um
wrong forum bro

[xeilou]

Quick follow up on the original issue posted:

Went to the shop that did the APR tune. We drove the car, and he said that it seemed to be a minor boost fluctuation issue which only presents itself when you are slightly adjusting throttle somewhere in the mid RPM band. We also noted that the dog bone mount was junk at 95,000 miles (some on the track) and new bushings should help remove some of the jerking back and forth from on/off throttle/boost. So friday a new dog bone is going in.

I think his take-home message was that this may just be a product of the higher boost (17psi vs 10psi) in the tune and that there may be some degree of this to deal with if I want to run a tune. If I switch back to the stock map, the issue is gone. Keep in mind that the issue did occasionally present itself BEFORE I ever got the tune.

Does anyone know if this is a common (maybe not discussed much) problem for doing stage 1 tunes? I've been told that APR was some of the smoother tunes, but maybe it's an APR issue?

Dear AEGTI3913,

Please keep updating! Me a guy in China is having the same issue. Mine is APR stage 1 too! My model is BORA R (a special model for Chinese market), I'm sure it's on the same platform of GTI. The support is not strong in China cuz GTI was not popular until 2007 in China. Looking forward for your update! (You see I can only turn to an English forum)

[AEGTI3913]

Dear AEGTI3913,

Please keep updating! Me a guy in China is having the same issue. Mine is APR stage 1 too! My model is BORA R (a special model for Chinese market), I'm sure it's on the same platform of GTI. The support is not strong in China cuz GTI was not popular until 2007 in China. Looking forward for your update! (You see I can only turn to an English forum)

Nihow Xeilou. The tuning is on hold right now. I may try GIAC tune soon because there is a dealer near me. I will update if and when I try this.

The best explanation of the problem I have heard so far (anyone with more knowledge, please correct or add info):

-1.8t motors have a recirculation (of boost) system where you can either be A) building boost and sending air into the motor, or B) recirculating air and NOT sending air into the motor. The diverter valve (DV) is the switch that opens or closes this air flow.
- The DV is an ON/OFF switch. There is no partial open or close. It's open or close.
- If you are building boost the DV is in one state, say open. The air flow is moving like a train down a track, moving fast.
- When you let off the gas, the DV switches to the other position to recalculate the air. The door is slammed shut. This is an abrupt change.
- When you tune a car and increase boost, this change is bigger and can be felt more. Boost on or boost off. More boost, feel it more.
- When you are mid-throttle, the car has a harder time knowing if you are building boost or recirculating. And if you are feathering just a little throttle more or less gas, the DV is switching open and close.
- When this abrupt changing of intake air is changing from building boost vs. recirculating, it MIGHT be causing this weird big drop in throttle feel. Because the boost is higher after a tune (10psi stock, 17psi at max boost on APR 93) it magnifies this ON/OFF boost build.

My DV is new. My throttle body is clean. The only thing that has been suggested so far that I haven't replaced yet is the Mass Airflow Sensor only because it's not a cheap part, and apparently you can't test it to see if it's not working 100%. The MAS detects the amount of air coming in to the motor from your intake. If the motor can't get accurate readings on air coming in, it could be telling the DV to switch ON/OFF at the wrong times. (?)

I'm not a mechanic, but I'm trying to understand the problem to fix it. Because the car is now running a stock tune at 10psi, the car runs fine. But, I of course want to tune the car.

I hope this is helpful.

[805 GTI]

you could try cleaning the maf sensor, i know that helped me out

[AEGTI3913]

you could try cleaning the maf sensor, i know that helped me out

Thanks 805. Any suggestions/DIY info on how to do this properly?