i have a stumble at 5500 rpms, it's like a wall is there. sound like a drag car on the rev limiter at 5500 WOT.

injectors were just cleaned, fuel pump is hard wired, emissions removed. idle's rock steady.



need help

 

is it fine after the stumble or does it just hang there?

 

try rewiring all your ground and power wires. theres A pretty good write up on ROTARYRESURRECTION.COM.

Also make sure theres no vacuum leakes.

 

I had a similar problem that went away after fixing a vacuum tube leak ('90 Turbo II). I was futzing with other things a the same time (Throttle Sensor Positioner, etc.), so not sure if this was the true fix, but it makes a lot of sense after reading the sensor description. When accelerating hard under turboboost my car would stumble (misfire? knock? clutch slip?) at about 5500rpm.



The leak I discovered (while getting to the TPS) was the vacuum tubes (yes, there are two) going to the Duty Solenoid (Turbo Boost Pressure Control). The ID of the tubes was a little too large to fit snugly on the sensor nipples. I fixed this by inserting a short section of electrical heat shrink insulation over the nipples, and continued to use the old tubes (silicon).



To locate the sensor stand in front of the car near the battery, look at the oil filler cap, power steering dip-stick and front right (drivers side) corner of the intercooler. Within that triangle and about 3 inches below and rear of those points is the sensor. See 1990 workshop manual, pages F2-3 (detail 11) and F2-41 for sketches. Maybe not necessary, but solenoid test from the manual is as follows - disconnect solenoid valve connector, measure resistance 30 - 40 ohm desired. Apply 12 volts to terminals, listen for clicking, replace if no clicking.



Hope this helps.



VB