Mechanics

HESITATES, OR HICCUPS

1991 Toyota Previa

Engine Performance problem
1991 Toyota Previa 4 cyl All Wheel Drive Manual 125000 miles

The check engine light just came on, the change oil light has been on for a couple weeks while we have been replacing parts and trying to figure out what could be wrong. The Previa will hesitate kind of like a hiccup, it doesn't loose any power when it does this and it will happen in a higher rpm while foot is on gas petal. I have replaced the fuel filter, the throttle position sensor, airfilter, distributor cap, rotor, spark plugs and wires, haven't changed the oil but was changed not too long ago and still has the honey color to it. More recently within the last couple days of driving the Previa it has started to stall out when decelerating and coming to a stop, and the idle will fluctuate, and this is when the check engine light has come on. Any ideas of what is wrong or what I could look into next?
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Previastumped
July 13, 2009.



Pull the codes from the computer by jumping Te-1 to E-1 in the check connector under the driver's seat to find out what's going on. Could be the idle air control valve/TPS/MAF sensors-to include cleaning out the EGR valve

Rasmataz
Jul 14, 2009.
I brought the Previa to get a diagnostics ran but they could not duplicate the problem in the shop so they didn't run the test, but the mechanic drove the van and said that he had worked on a similar engine and said that replacing the crankshaft sensor on the distributor had fixed the problem, he said the part ran around $400. I would like to know if this sounds like a probable cause for the symptoms I had previously described?

Tiny
Previastumped
Jul 17, 2009.
Say what! He replaced the crankshaft position sensor-To start with this 91 Previa don't have a CPS in his dreams-I owned 2 of these vans 91/95. Get away from him, he's nothing but a partschanger

Do this remove the EFI fuse for 10secs and see what happens to CEL.

Rasmataz
Jul 17, 2009.
Clean the carb with carb cleaner or petrol and use old toothbrush to clean theres more on this site about said subject

Tiny
Bikerboy
Jul 25, 2009.
Have you checked for a pinhole in fuel filler neck? Do you get the hiss, when you remove fuel cap?

Tiny
Toomanymiles
Aug 25, 2009.