Running really rough

[dsm4fox]

Ok so I got ahold of a new 90 1g. Have been driving it off and on for about a month, too and from work. I drove it for about 5 days straight. It sat for the weekend and then drove it twice. On the second day.

I noticed going in it seemed to be flattening out the power as soon as boost hit under heavy throttle.
On the way home in ONLY 3rd 4th and 5th. It sputters and has no power as soon as boost hits.
I noticed in 1st and 2nd there is no issues what so ever..

Car is almost completely stock other than upper ic pipe and intake. Where do i begin?

Car has 190,900.. Almost all original other than basic P.M. replacements

 

[MitsGray97]

Have you done any blt's? And whats your fuel pressure and afr look like? You could also try a tune up.

 

[Boddie]

Like the previous poster said, try a boost leak test. I found a lot of leaks on my car when I did it. Also do you have an aftermarket boost gauge that can tell you how much boost you are actually getting at these times? A cheap $25 one from an auto store may be of some good help.

 

[gieri002]

Yup, boost leak test forsure. Let us know your results and we can go from there.

 

[dsm4fox]

I was plannin on testin it this weekend. I have a boost gauge. Thats the only gauge added at this point. Was planning something big for this car so i have to figure this out I know its in dire need of some major tune up/maintenance. But i believe boost leak is whats going on here..

From what ive seen of the car the longer you drive it consecutively the worse it runs. let it sit and she runs great.. I did a comp check on her when i got it. But might do another one this weekend.. I will post some results when i get into it. Which "may" happen.. I am a full time single parent time is sketchy these days...

 

[dsm4fox]

Ok so i made a DIY at home leak tester. Started at the turbo... Wouldnt hold air. Finally moving down the line i got to the UICP and it wouldnt hold air but the t body elbow it does hold air. So i cap'd off the end of it and tried it again.. and the BOV i believe is leaking i cant get it to hold over 1lb of air roughly..
ALSO
The intake pipe had a HUGE split/crack in it and it fell apart when i took it off :/ so now i have 2 possible issues.. Good news is the Tbody elbow in, DID hold air...

 

[dsm4fox]

ARG damn car.... looks like ill have to dig in deeper... Replaced BOV, vacuum lines. Did a leak test. Holds pressure now.. BUT runs rough as hell still... Actually runs really bad.. Thing sputters and is miss firing at all rpm ranges and each gear now. and sounds like a lawn mower engine when its idling
awesome

 

[fenixnr]

How much pressure did you do the BLT for? The same as you are running? Less? Are you throwing any DTC's?

 

[dsm4fox]

well originally presure was held to 15 on my leak test. but the turbo is only pushing 10. idk what happened but now it wont hold pressure at all.. but i cant hear any leaking at all Ive tried the leak test from the turbo again..

before hand the part that didnt hold pressure was the BOV. Past it at the throttle body it held pressure well.

I replaced the BOV and the car fired right up. Ran really good, got about a block away from the house and now it runs like total utter sh*t it wont even idle right.
It sounds like a damn lawn mower sputtering when you first give it throttle then it picks up and revs.
IDK what happened but it was idling fine when i got it back together.

It wasnt till after my test drive it took a dive for the worse..
SO then i took it apart inspected my work. connections. and re installed everything and did a test at the turbo inlet.. NO pressure is being held Something ugly is going on but im about out of patiences right now..

as far as i know, no dtc

any and all of my diagnosis tools are in storage due to moving from my divorce crap from a few months back.. I dont even have my compression tester.. I had to buy the parts to make a quick boost leak tester..

 

[pauleyman]

And you found this out how?

 

[dsm4fox]

Been a bit since ive updated this one... Thought id give everyone the info on what happened... Started pulling everything apart. Found that, the cylinder in question had actually fried my valves. The exhaust valves on that cylinder were shot. One was cracked and broken half way around the edge of the valve. the other one was cracking on the valve's stem the head gasket was bad but was mainly leaking from a passage to outside the block, the intake manifold was causing a boost leak from broken studs and bad worn out gasket as well.. AND the 14b turbine has a crack in the housing. a crack in the manifold as well.. The crack inside the turbo goes from the top of the turbine down, past the WG passage and straight down into the scroll area of the 6cm housing. The wheels apear to have NOT gotten any damage from valve debris so thats good news, turbo has no play which is also good. Planning now for a new head assembly, Machined block with new pistons and rings. HG. and possibly upgrading the 14b with a 7cm housing along with possibly a evo3 mani

 

[98_tsi_]

damn man sorry about your luck....

 

[White_knight]

Boost leak
After u find all the leaks check the spark plugs
Platinums NGKs gapped to .028