Previa stalling

THEVANDRIVER

MEMBER
TOYOTA PREVIA

Hello
I own a 1996 Toyota Previa LE with supercharger, 2.4L 4 cyl, RWD, mileage = 312935 kms. Vehicule is OBDII.
I have been taking very good care and there is virtually no rust. Currently, after reaching operating temperature, the vehicule rpms will drop and when coming to a stop, it will stall out. Otherwise, I can drive fine on the highgway, for example. I get no engine check light. I have taken it to numerous garages and no one can solve the problem. The Toyota dealer had it there fo 10 hours at one point. There is no electrical problem either. The problem (stalling) always occurs after the same time interval. It does not appear to be an intermittent occurance. Also, after the stall, I cannot start up car. I need to wait for a cooler engine then I can start ( with difficulty sometimes) and drive away. The next morning, it starts perfectly. This is what I have replaced so far:

New exhaust system from front to end (including bot CAT. CONVERTERS), except muffler ( muffler appears to be fine) Both O2 sensors Distributer and wires. Spark plugs are regularly changed. Air filter is clean Throttle position sensor Gae filter Fuel pump appears to be working well Idle air control valve EGR valve Chaged ECM twice (from other donor vehicules). Check engine light funtions! Mass air flow meter, twice (from other donor vehicules) Have performed ignition coill test ( with a donor coil)

I have not changed alternator ( but I do have brand new one )

Could this problem have anything to do with the coolant temp sensor? I did a resistance test across the open terminals at hot and cold and got two different readings.

I regularly drain and refill the engine coolant but have never flushed system

Any advise would help
Thanks

tg

2 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Could this problem have anything to do with the coolant temp sensor? I did a resistance test across the open terminals at hot and cold and got two different readings. What are the readings?

Recheck the VSV solenoid for the EGR valve might be coming On too soon when not needed and comeback

Or do this make sure the EGR valve is fully seated plug the vacuum hose to it and duplicate the problem

Also might need to change the TPS wiring, check the dealer in regards to this there's a problem to it I can't recall what it is. I did this on a 95 w/o the S/charger.