Help Needed -- 1988 5000KSQ
urq at pacbell.net
Mon Jul 28 07:15:37 PDT 2008
IMO the symptom that the engine runs well until it warms up has me siding
with those saying OXS ... but the first thing to do is to read the codes
from the ECU ... there should be OXS codes if this is the culprit ...
That said, going forward with the intake tract leak ... my first suspect
would be the crankcase vent hose that runs down from the valve cover on the
spark plug side of the engine. The original post indicated that there was
some work at the back of the engine compartment done recently, and the cast
rubber piece that attaches to the crankcase vent can deteriorate to the
point where it is easily damaged. IME, when this hose goes you can get
enough of an intake leak to cause the engine to stall under power.
San José, CA (USA)
Ben may have hit the nail on the head there, the leak in my igloo was
particularly difficult to find. Check under the clamps, they can tear there
and be virtually invisible.
An often overlooked boost hose is the LOWER intercooler hose, which is made
of VERY thick rubber (on your car, there may be a hard pipe between two
rubber ends). Unfortunately, intake tract oil will eventually work it's way
through the rubber, and your car is certainly old enough for that to have
happen. You will really need to remove the hose to find leaks in it, and,
because of it's thickness, it can act intermittently as the thickness helps
it retain some integrity, particularly if it's cold enough to make it act
stiff. Ask me how I know....
IF you need the upper Michelin Man hose (also best to check when removed,
then accordian them with a small light inside) I have some NOS ones that I
haven't had the time to post to get rid of.
LL - NY
On 7/27/08, Ben Swann <benswann at verizon.net> wrote:
> A few educated guesses - in short the car runs but has no power.
> The air fuel mix is likely off and probably there is an intake tract
> leak. If it were
> post turbine, the car would likely run funny and have no real boost, but
> still get out
> of its way. It therefore sounds like there is a serious leak from the air
> boot "waffle
> hose" down to the turbo somewhere. I would hazard a guess that the waffle
> boot is
> simply not seated on the fuel distirbutor and you'll find an easy
> fix. Else there is a
> rip in one of these hoses, and maybe one blew off at the intercooler ofr
> turbo - under
> car. Could even be the Michelin Man hose (goes from intercooler to the
> throttle) and
> they rip all the time - just with that tear the car should still be able
> run, just
> not get positive boost pressure.
> So - pop the hood and start looking. I bet you find it is an easy fix -
> might need a
> temp repair with some tape and goo if it is a special hose - namely the
> waffle hose.
> The intake tract need to be tight in order for air to be pulled in by the
> engine whereby
> fuel air plate is lifted and proper mixture attained for engine to run
> Might be temp sensor, O2 sensor, or some ECU related problem, but I'd
> for air
> leaks first. Would have to be one hell of a clogged fuel filter for that
> to be it and
> fuel pumps generally cut and go - a bucking.
> That is my SWAG at it. BTW MTFS really has nothing to do with engine
> operation - all
> coolant/temp related which is a separate harness. There is a separate CTS
> for the
> From: b1biker at aol.com
> Fellow listers, one more problem in the continuing saga of resurrecting
> this car.
> Yesterday I installed a new power steering pump and a 'new' from the
> multifunction temp sensor. After completing the work I discovered that
> the vehicle
> reaches operating temp it will no longer rev and has difficulty even
> pulling itself; it
> almost seems as though it doesn't have enough fuel. Fuel pump is new but
> seems to have
> gotten quite a bit noisier with the onset of this problem. I suspected the
> temps sensor
> so replaced it with the original unit but the problem persisted. I pulled
> the fuel pump
> to see if the screen was plugged; everything seems to be OK. Any help in
> finding the
> source of this problem will be greatly appreciated.
> Gary Meier
More information about the quattro