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Dutch_DSM
02-22-2004, 04:46 PM
Today i was finally able to try and start up my '90 TSI again after I replaced a spun bearing. (new crank & rod)

The car will start but is running really rich
and the stock boost guage is way off.. showing boost on idle.

I was thinking the MAF but when the ignition is on the stock guage is on 0 like it should be
And when I push the throttle a bit the stock guage goes up all the way to max boost and offcourse the car blows out some black smoke and stalls because it's running really rich.

Any idea's what could be the problem?

Can it be a vacuum hose? because i had all disconnected
The ecu was also out of the car to have the capacitors fixed.


Mods: None car is stock!

Shane@DBPerformance
02-22-2004, 05:00 PM
Sounds like a boost leak or bad MAF.

john
02-22-2004, 05:00 PM
Do a boost leak test. Could be a boost leak.

LightningGSX
02-22-2004, 05:11 PM
It doesn't sound like a leak, it sounds more like a MAF problem.The factory boost gauge works off of the MAF(airflow), if it were a leak the boost gauge wouldn't be showing "boost".Check the MAFs connections and ground.

LightningGSX
02-22-2004, 05:12 PM
I guess obstructions in certain places in the MAF could cause high reading also.

john
02-22-2004, 05:15 PM
Wouldn't a bad MAS pop a CEL though?

LightningGSX
02-22-2004, 05:20 PM
Not in that case, its seems to be just reading excessivly high airflow, which may not be considered a fault by the ecu.

Edit: Ignore the OBDII comment

LightningGSX
02-22-2004, 05:32 PM
Looking at my disassembly of the 1g ecu code, it appears the ecu only checks the MAF for out of range faults, meaning above or below the limits of the sensor.

Dutch_DSM
02-23-2004, 05:39 AM
I'll check out the maf & connectors again.

THe MAF looks de be in good shape. not hacked or anything and even with the filter off it's still the same.
I'll have to lookup what the normal value's are and measure them to see if they are within normal.
Anyone know how to check if a MAF is still oke?

By the way can it be that the idle speed control has anything to do with it.

Because after the engine stalls it starts makeing all kinds of funny noises.

Dutch_DSM
02-24-2004, 07:56 AM
It seems de O2 sensor isn't working either (always 0v)

Could this be related?