hits about 5k rpm, the car falls flat on its face

[jmatyas]

ok. so here we go again. So here is the problem. When i get on the gas and the turbo spools up and the car hits about 5k rpm, the car falls flat on its face and acts as though there is no turbo in the car. As though the boost was never there, but up till about 4,500 to 5k the boost and everything is fine.

I took it down to a dyno shop and this shows how bad it is. I dyno'd at 105hp with 155 torque. !!!! I had it at there shop for 6 hours today and everyone there was at a loss of words. We checked everything. boost leak... none, hoses in place and new. yes. I have no idea of what to do.

Come on my dsm friends. help me figure this out before i dump it off at the junkyard.

Oh also in case your wondering this is all that has been replaced. o2, maf, timing belt, boost leak test, fuel pressure, spark plugs and wires twice, over $4500 in replacement parts and labor has gone into this car....and its just almost stock... im about the cry...

 

[Artago]

Can you post a dyno sheet and possibly a log with AFR readings.

I'm assuming you are still on a stock turbo.

Any CEL codes?

Tom

 

[jmatyas]

i should have taken the slip but i was too embarresed to take it. By CEL codes what do you mean? sorry im still kinda new to the whole tuner thing. I dont have a check engine light or any codes up on the obd2. also on the dyno run we saw that it ran a tiny bit lean then when it hit 5k ish it went as far rich as it could and tons of black smoke came out the exaust. sigh.

yea its still a stock turbo, the car only has 47k miles on it so its still young and fully boosting. no boost loss.

 

[Artago]

no boost loss.

Are you sure?

From what you are telling me you have a massive boost leak.

Probably at the BOV (Blow off valve). If you are still running a 2G BOV, which I assume you are, then go buy a used 1G BOV and adapter (from eBay or a member on this forum) and install that.

I had the exact same problem when I bought my car. Turns out it was a series of boost leaks. Pipes, couplers, 2 massive ones at the intercooler, and one at the stock plastic piece of sh!t 2G BOV.

Search the for for how to build a boost leak tester, and test the system

I can almost guarantee the 2G BOV is leaking but build the tester anyways and test because there may be other leaks.

Again, this sounds like a boost leak issue. Search the forum and read up on the symptoms and you'll see what I mean.

Good luck,

Tom

 

[rush2252]

+2 One would assume with only 47K the problem is as simple as the 2g BOV leaking.

CEL is Check Engine Light. Its bound to have a light if its throwing a code.

-Kolby

 

[habitatguy187]

I can almost guarantee the 2G BOV is leakingTom

+1. What psi are you at when the power loss comes? Do you have an aftermarket boost gauge? What happens on it when you lose the power?

 

[rocafellafw]

Kinda sounds like my problem, car cruises fine but when you go WOT the car sputters, holds 10 psi fine and just goes NOWHERE, I've spent the last 3 monthes going over what we did that caused the problem. (was fine before we unhooked everything needed to do mounts & UICP)

 

[jmatyas]

we installed a autometer boost gauge and it read just over 8 psi the whole dyno run. never lost boost as far as we could see. all hoses have been replaced just to make sure it wasnt that easy of an answer.

the car starts to sputter and spew black smoke out the exaust when it starts dropping power, it rocks and kicks power in and out as dumb as that sounds. even on the dyno sometimes it would buck like a horse when it hit that power wall. also the air/fuel ratio when from optimal to 100% rich when the problem would arise.

thanks for all the help so far guys. help me break this curse.

 

[rocafellafw]

even on the dyno sometimes it would buck like a horse when it hit that power wall

I also get that symptom, by any chance does it ever feel like it tries to "clear" up, like do you sometimes get a glimpse of power ?

 

[jmatyas]

I also get that symptom, by any chance does it ever feel like it tries to "clear" up, like do you sometimes get a glimpse of power ?

i have felt it do that maybe only once. but i do know what you mean. the only downside is that it also feels like ive hit the rev limiter even though it still has another 2k+ to go till you hit it. ive never had a problem like this.

 

[DSMTriad]

Hmm I'm having the same problem with my 92 TSi. The turbo/exhaust manifold was bright orange and the spark plug wires were arching each other and the throttle cable. And I'm starting to smell gas myself. I'll let you know what I come up with when/if I fix it.

 

[habitatguy187]

Still sounds like a boost leak, especially after your last post. I say this because of 3 reasons.

1. Stock boost should be around 11-13psi.
2. Black smoke means running rich, the ecu reads all the air entering the system and adds fuel to compensate for the air, if you're losing air (boost leak) that the ecu is accounting for and adding fuel for, then you'll end up extremely rich because the fuel is there, but the air isn't.
3. The stock bov is VERY prone to leaking.

You need to build your own boost leak tester. IC Pipe Tester And do the test yourself, take off the recirc. hose on the bov and see if it leaks.

 

[ViperXavier]

Hmm I'm having the same problem with my 92 TSi. The turbo/exhaust manifold was bright orange and the spark plug wires were arching each other and the throttle cable. And I'm starting to smell gas myself. I'll let you know what I come up with when/if I fix it.

This sounds like your cat is clogged and or the following timing is to far advance and fuel that is still ignighted is being pushed thru the exhaust valves due to timing advance and or burnt vales

 

[jmatyas]

UPDATE!!

boost leak tester built and tested. had a very small leak by the bov. that was all. surprisingly the bov wasnt leaking. well not yet . didnt fix anything.

timing was just ckecked as well and its perfect. brand new belt is staying true. still still cant figure it out. the part that still gets me is why does the car run perfect then run ultra rich... i dont get it.

 

[jrohner]

If you're only making 8 psi, most likely your boost control solenoid is staying shut. I'd yank the hose off from the BCS, and give it a try; then you should be at around 14psi. These cars with the tiny stock t25 turbo are slow enough at 14 psi, I can't imagine driving one at only 8. I would not be one bit surprised by your dyno numbers at that amount of boost, the shop you brought it to must not be familiar with these cars if they couldn't figure that out. Why did you dyno it anyways -- just to try help figure out your problem?

 

[jmatyas]

we threw it on the dyno because they wanted to see what exactly it did when it hit the problem. So they could moniter everything pretty much. I really need to get ecmlink but the cost pushes me away.

i havent had a chance to buy my tripple pod piller so it was the best way to watch and see what it did.

 

[Dsmj89]

Have you tried changing the wastegate arm ? It's probably staying stuck open. Spray some wd40 on it and test the car out.

 

[DSMTriad]

This sounds like your cat is clogged and or the following timing is to far advance and fuel that is still ignighted is being pushed thru the exhaust valves due to timing advance and or burnt vales

Ah might be all the above. Damn heat from that turbo melted the plastic shroud for the rad. fan stopping the fan from moving. It blew the rad. fan fuse and started overheating not to mention I still have a boost leak.

 

[jmatyas]

wastegate was one of the first thing checked. works like a charm. sprayed some wd on it anyways to make sure it stays working. thanks for the tip .

i bought this car back in aug of last year and ive driven it a total of a month worth of time. it would be nice to finally drive my car . well.... drive it like it should be driven .

 

[Artago]

Still sounds like a boost leak, especially after your last post. Agreed. I say this because of 3 reasons.

1. Stock boost should be around 11-13psi. Correct.
2. Black smoke means running rich, the ecu reads all the air entering the system and adds fuel to compensate for the air, if you're losing air (boost leak) that the ecu is accounting for and adding fuel for, then you'll end up extremely rich because the fuel is there, but the air isn't. Exactly. Beside 8 PSI is way to low and even if you are seeing full pressure you could still be losing volume
3. The stock bov is VERY prone to leaking.Amen, even if it's not leaking (which it probably is, get a 1G anyways. $20-$50 depending on how resourceful you are

You need to build your own boost leak tester. IC Pipe Tester And do the test yourself, take off the recirc. hose on the bov and see if it leaks. +1, agreed

UPDATE!!

boost leak tester built and tested. had a very small leak by the bov. that was all. surprisingly the bov wasnt leaking. well not yet Not sure what you mean by "not yet"??

If you're only making 8 psi, most likely your boost control solenoid is staying shut. I'd yank the hose off from the BCS, and give it a try; then you should be at around 14psi. Good idea, try it. You should see 14PSI

I really need to get ecmlink but the cost pushes me away. It's worth EVERY penny.

i bought this car back in aug of last year and ive driven it a total of a month worth of time. it would be nice to finally drive my car . well.... drive it like it should be driven . I know how you feel, I've spent about 6 months in the past 2 years actually driving mine, but I think I finally have all the gremlins worked out, mine should be back on the road with a few weeks. I'm a true DSM believer in that I believe that it WILL all come together and the I WILL have a wicked ride.

Cheers,

Tom

 

[DSMTriad]

I thought I was the only one who would have a DSM for a year and drive it for only 2-3 months.

 

[jmatyas]

looks like ill be heading in to deff do that 14psi check. ill have to look and find where the BCS is. i would love to see if that is the problem. thanks for the tip .

i do still need to replace the stock bov. im bidding on one on ebay as we speak. i will have that swaped asap!!

ill do another boost leak test tomorrow and see what happens. Ill push it to 20psi for the test this time. i was being careful and only doing 15psi the first time. your right only 8psi is very low.

I wish you guys lived in my area, youve all been helpful and it would be fun to have worked on it with a few of you. thank you all so far with your help.

 

[habitatguy187]

The bcs restrictor is located on the hose coming from your j-pipe nipple. It's a black thing attached to a vacuum hose on each side.

 

[Artago]

looks like ill be heading in to deff do that 14psi check. ill have to look and find where the BCS is. i would love to see if that is the problem. thanks for the tip .

i do still need to replace the stock bov. im bidding on one on ebay as we speak. i will have that swaped asap!!

ill do another boost leak test tomorrow and see what happens. Ill push it to 20psi for the test this time. i was being careful and only doing 15psi the first time. your right only 8psi is very low.

I wish you guys lived in my area, youve all been helpful and it would be fun to have worked on it with a few of you. thank you all so far with your help.

You'll need an adapter for that 1G Bov as well.

BCS removal: http://www.dsmtuners.com/forums/art.../185405-bcs-restrictor-removal-explained.html

Good luck,

Tom

 

[99Mitsu]

it must be a universal problem with DSMs ### my 99 GST does it also...usually when i go WOT i have to shift down and back up...(btw, my cat is stock too)

my throttle response s**t...i'm thinking of checking my fuel system...if only i could afford the $375 AFC controller

i think the problem will go away once i do some poking around with the fuel systems