Boosting 17 PSI on stock chip???

[Fuzz_Duster]

My car is really screwed up right now. When I give it gas, it bogs so hard, and hardly moves, then it wil buck forward and go for a second, then bog down again. Every gear, from 2k RPMs to 5K RPMS. It jsut bogs so hard when you hit the gas. Second, from 1.5k RPMS to 3k RPMS, the boost spools up to about 17 PSI!!!! I can hear it over my radio. Its F**KING LOUD. Its like a big "SSSSSSSWWWWWOOOOOOOOOOOOSSSSSSSSSSSSSSSH" sound up to 15PSI, then the boost needle will jump from 15 to about 17 a couple times while the car bucks and sputters, then suddenly drops back to around 5 PSI (stock boost). The car's jerking the whole time. It drove PERFECT yesterday. This all happened after that car sat overnight in my driveway. Please tell me its something simple like coilpacks and sparkplugs and not a blown turbo...

[Fuzz_Duster]

Oh, and NO CEL.

[ExSRAaron]

Big boost or vac. leak maybe?...

[Nebone]

Looks for loose vacuum lines.

[Fuzz_Duster]

well when it decides to run smooth for a minute or two, it will peak 10 PSI WOT third gear, and around 5 for just normal hard driving.

I should also mention I put a giac chip in yessterday, and the car started doing that with the giac in (boosting really high and bucking/misfiring) so I switched back to stock and it ran like it has for the past year, GREAT.
Now my stock ECU has the giacs probelms....

[Fuzz_Duster]

any diagrams to let me know where to find most of them so I can check them? **to nebone22**

[nrowensby]

Timing belt been done recently... Sounds exactly like how my car was acting when timing belt slipped a couple teeth.

[Fuzz_Duster]

timing belt was done at 100,000 miles. I'm at 153,000 right now.

[Nebone]

You might have a busted diverter valve and possibly blow off vacuum/boost line. The valve is under the passenger headlight and just look around at hoses to see.

[nrowensby]

Aren't you supposed to do them every 60k?

[Sobo]

N75 valve, N710(DV valve)

or wastegate actuator sound like the culprits.

I got a NIB n75 valve if ya need one cheaper than usual, if thats what it is.

[Fuzz_Duster]

N75 valve, N710(DV valve)

or wastegate actuator sound like the culprits.

I got a NIB n75 valve if ya need one cheaper than usual, if thats what it is.

already replaced the DV with a forge splitter.
The n75 is good, I just pulled it out and checked it. No cracks or tears or anything. But I still might hit you up on that when I get paid if you still have it.


It's fine now. I have no clue why it was doing that. It still has the occasional very light bucking/bogging feeling at high RPMS, and the begging of 2nd gear, so I think it has to be coil packs and plugs. I have plugs but I'm waiting on coils.

And while I'm talkiing about spark plugs, does anyone know how the hell you get the engine cover off on a '98 1.8t? It has screws but when I try to unscrew them, they go half a turn then pop and just do that repeatedly. Like they're fake or something.... and they're kinda jiggly/loose in the seat. I tried just pulling up on the cover and it cracked a little so I stopped...

[ExSRAaron]

lol, the screws spin then pop off, loosen all of em and pull the cover off. GL

[Stampy]

And while I'm talkiing about spark plugs, does anyone know how the hell you get the engine cover off on a '98 1.8t? It has screws but when I try to unscrew them, they go half a turn then pop and just do that repeatedly. Like they're fake or something.... and they're kinda jiggly/loose in the seat. I tried just pulling up on the cover and it cracked a little so I stopped...

Wow. Maybe you should have someone else work on the car?

[Lazer Viking]

check your n75

[Militant-Grunt]

Do you have a manual boost controller?

I was boosting 21-23 lbs (gear Dependant) on my GIAC file as well.

It sounds like misfires to me, id say ICM or coilpacks.

[bigphil]

I'm guessing you don't have a vagcom? Reminds me of my MAF, no CELs, just weird misfires and I could still hit boost regularly. If you datalog it would probably show up pretty quickly.

[maxspeed]

sounds like your wastegates going out

[TQMB5]

sounds like what happend when i had a big boost leak...

[Fuzz_Duster]

Wow. Maybe you should have someone else work on the car?

yeah, cause I don;t know how to remove the engine cover....

[Ewok_Fetus]

yeah, cause I don;t know how to remove the engine cover....

Yes, because 3 simple half turn screws are NOT that hard... If you fuck that up, then you will fuck other things up...

[Stampy]

I was being serious dude. Typically the engine cover doesn't require a DIY write up.

[ceas]

I really think that this is a major vacuum leak. When my turbo inlet hose popped off it acted just like this. And it seems as if your going to have a hard time trying to find a leak, so just take it somewhere.

[Fuzz_Duster]

Yes, because 3 simple half turn screws are NOT that hard... If you fuck that up, then you will fuck other things up...

I was just asking for a little help...not a full writeup. I figured someone would be cool enough to give me the simple one sentence answer.

anyways, I have a full time CEL now, and car's in limp mode with stock chip in. Coils are still in the mail . SO for the next couple days I get to drive a sick 4 banger like a little bitch till they come in. I would drive another car, if I had one...

[Fuzz_Duster]

I really think that this is a major vacuum leak. When my turbo inlet hose popped off it acted just like this. And it seems as if your going to have a hard time trying to find a leak, so just take it somewhere.

its not a boost/vac leak. I'm sure that would show up on my gauge. It has to be coils from what I've narrowed it down to with all the symptoms.
We can let this thread die now.
Thanks for all the help though guys.

[steezybme]

yo need to first fix a vacuum leak.

Then buy a turbo xs hpbc.

Do the diode mod.

Set boost back to 14 psi, so its safe and like magic your car will perform fine again... Thats if you havent messed up anything...

The hpbc by turbo is a bleed valve also, so you wont have to worry about any spikes that will further make this happen...

[steezybme]

also buy some "mass air flow" cleaner it says mass air flow cleaner on the bottle... Just go ahead and clean that because you probably fouled it before you have to replace it... And if its faulty just go ahead and upgrade to the TT MAF because the a4 maf wont run as well with modding...

[Stampy]

It's not the coilpacks. When they go, they go. The CEL would be blinking, and the car would have a ridiculous misfire. The proper way to tell if its the coils is to scan car. See which cylinder is misfiring and swap the coilpacks. See which cylinder it the misfire switches to. That is the bad coilpack. You can achieve this with VAG or a generic OBDII reader

[BBEYER164]

It seems like i got the same problem on mine, it only happens when its really warm outside. when i first go, i have solid boost, but as the car warms up, it seems like i loose boost ....... i also got the giac tell me whats goin wrong!!

[Fuzz_Duster]

Changing plugs right now. I have VAG com. Tested the CEl last night @ idle- Got a code for too lean (MAF) and terminal 30 low voltage (switching the ECU's out so much...). Cleared the CEL and took her for a drive. Still bucking and overboosting/popping at anything past 3.5 RPMS. So I stopped and turned the car off. Turned it back on, and it was in limp mode. CEL came back on halfway home.

Also did some logs and from what I can see everything is fine besides the MAF. Its readings were kinda all over the place. I'm going into town to buy some MAF cleaner after I change my plugs and clean that out. Will also double check the N75. No vac leaks, it sits at 18 cold idle, and drops to 20/21 when the engine warms up. Driving idle it sits about 18-15 .
My guess now is- Dirty MAF-->Bad Readings-->Running Lean--> Fouling Plugs--> Misfiring.


So,
Step one- change plugs
Step two- check/clean MAF
Step three- check N75
Step four- check for boost leaks

[steezybme]

check maf first clean that then pull the plugs... they mite be fine, even if they are black just clean them when your car runs rich it coats them black... But if you decide to get new plugs roll with ngk and nothing but ngk the bosch ones are S$%#...

also chipping your car and or adding a mbc will fix your lean problem and limp mode situation...

[im sofa king]

Sounds like a timing issue to me

[BBEYER164]

timing belt was done in january.

[Fuzz_Duster]

Boost leak anyone?

The turbo inlet hose, right where it clamps to the turbo, was ripped 3/4 of the way, and is just hanging on by a little thread of rubber. Which explains the loud ass turbo spooling I hear. Its just all the air hissing out of the turbo into the engine bay. :/ Taking it in monday and a guy who specializes in tuning euro cars is building me a custom aircraft grade aluminum inlet setup along with a heat shield and cone filter "straight shot" hose. He garunteed it would last longer than the car and will hold up to 600CHP (he owns a 2.8 b5 with 565AWHP and is using the same setup on my car thats in his.)

[Ewok_Fetus]

How come we don't know this guy with a 565 AWHP 2.8?

[Fuzz_Duster]

I don't know? Its kind of a ricer car. He owns two other cars-One honda civic and one VW rabbit. He's got the whole back gutted out with just roll/stabilizer bars and the passenger seat is gone and replaced by a ton of wires running to all the guages and lights. He's got a body kit for it that I've never seen before, and its painted that ugly ricer primer color aka its just covered in a light grey coat of primer... He just claimed he was making 565 AWHP. I don;t know this for a fact.