mrmtbaldy

I've got a 91 200 that I recently starting having issues with. Intermittently, with no warning, the car loses power completely anytime it builds any boost. If it is running a vacuum, it runs fine, but as soon and the gauge goes over 0psi, all power is gone. It does sound like it is being blown off somewhere, like a malfunctioning blow off valve. But then, as quick as it came, it goes away and the car runs great again.

Nothing seems to provoke the car to do it, but it should be mentioned that the first time I noticed this, I left my windshield wipers on while they were frozen to the windshield. The motor was trying to run and got some things hot enough for me to smell electrical burning. Soon after that, was when the symptom started.

I pulled the codes for the first time in a while and got RPM sensor, hall sensor, MAF sensor, and oxygen sensor. I reset the computer and am awaiting new codes when I drive it more.

Any ideas?

bradwilcox

I think I've got the same problem on my 10v. In second gear (usually), going along, usually up an incline, the car surges slightly, the boost goes sky-high, and yet I have terrible power. This lasts about ten seconds. It's seemingly not the clutch, not the transmission, not the brakes clamping. Now I am thinking it is either totally ECU or perhaps a turbocharger issue.

richard-tx

Intercooler/Intake hose is leaking. What happens is the hose will leak under boost causing a too rich condition. If you watch the tail pipe when full throttle is applied, you will likely see black smoke. Take the host off and you will likely see the crack.

bradwilcox

Check to see if all fuses are present and good, including even the spares (yep). Especially check to see if the fuses that run horizontally underneath the main row of fuses are accounted for. Oh yes.

mrmtbaldy

So i pressure tested the system today and found a cracked and leaking hose in the rear of the engine as well as the air intake hose cracked where it meets the cold side of the turbo. I'm guessing this is having an effect on air/fuel mixtures and boost regulation. The small hose is repairable, but the intake hose is beyond repair. Does anyone know where to find this hose or something that will work?

bradwilcox

https://store.034motorsport.com/audi...ir-intake.html

fcpeuro

esctuning

autohausaz

mrmtbaldy

ok, so I replaced the intake hose and repaired the small breather t hose at the back of the engine...no change. This problem is really starting to baffle me. I've pressure tested the system and it has no more leaks. It feels very electrical influenced as it happens all of the sudden and returns to running good just as quick. As a reminder of my problems, when it chooses to present itself, the car will not idle without me keeping my foot on the throttle, once driving, when the car reaches any boost (over 0 psi) it completely falls on its face and will not build any boost. If it's running a vacuum, it runs ok but very rich and misses quite a bit. Also, when the problem goes away, the car runs much better, idles correctly, builds boost, but only to 12-14psi, which is off of the usually 20psi it normally runs (chip). I'm assuming some bad electrical connection that is influencing boost and fuel/air mixture maybe? Everything checks out visually, I haven't had time to start ohming sensors out. Any ideas?

richard-tx

Put a boost gauge on it and drive it. You likely will see a loss in boost pressure at WOT. If you have a gauge and cannot get any boost pressure then it is time to check the intercooler and the intercooler hoses. I have seen intercoolers fail before.