no power in acceleration

no CEL? is MAF sensor dirty? Possible/likely turbo boost issue. Here is a guide that will help

https://www.2carpros.com/articles/engine-has-low-power-output

Please run down this guide and report back.

1997 toyota previa automatic, power loss after driving for 30 minutes on the motorway speed drops from 60mph to 30mph despite accelerating. Thought it was transmission slipping but oil changed and appears to change smoothly, engine does not overheat and no engine lights on dash can anyone help?

Could be caused by one of the following below

Oxygen sensor.
Catalytic converter.
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Crankshaft position sensor
Knock sensor
Manifold absolute pressure sensor.
EGR Valve
Fuel pressure regulator leaking or defective fuel pump.
Fuel contamination.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.

Note:If it doesn't apply disregard it and keep testing.

Electrical problem
1993 Toyota Previa 4 cyl Two Wheel Drive Automatic
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I am just wondering how to remove the distributor and properly replace it. I suspect that is my problem.

For some time now my toyota previa will not rev beyond 2400 RPM, no matter how hard you accelerate. Also when it rains, or I run through a puddle, the vehicle quits.

I am also wondering how to access the spark plugs and wires as they are under the van. It is a Mid-engine setup.

I am greatful for any assistance you can provide

The throttle position sensor wire harness is known to be a trouble maker-that can be causing your problem.

To get to the distributor you need to remove the skid plate below it.

For the sparkplugs its under the passenger seat, you have to remove the seat and cover below it to expose them

I don't believe that it would be my TPS wiring harness as I got the replacement harness kit, and replaced a suspected bad TPS at the same time, which leads me to my distributor......

When you replaced the TPS did you check the closed and WOT voltages? Also tested the MAF sensor-

closed throttle 0 volts
WOT 10 volts.

Airflow meter was recently replaced for the one time low low price of $1427.43

ok finally got the plugs and wires changed and I cannot access the distributor cap from under the passenger seat. Is it better to go from under the vehicle? One more note, I had indicated that it would not rev beyone 2400 RPM, that is only when in gear. When it's in neutral or park, it will rev to red-line. Now, if I shift manually, it goes like a bat out of hell, but when it shifts on its own, it won't rev and there is no kick-down. Any thoughts? I have already been to the dealership and sought their advice. They inspected the cable and adjusted it to factory specifications... I am gettin frustrated with this vehicle. HELP!! PLEASE!!!

when starting it struggles to push forward

Does the problem seem to be related to the engine or the transmission? Has the check engine light come on? Have you checked the fuel pressure to the engine?

we just got the engine changed, the check engine light hasnt turned on, and where can i check the fuel pressure ?

For direction on checking fuel pump pressure, go to our homepage under the DIY section for directions and a video.