My 89 Toyota cus out at odd times when I slow down to stop. It starts back up but ithas been perilous at times. What is the cause and what can be done to fix this issue?

 

The cause could be many things. Does it always start after it cuts out? Have you checked for engine codes or looked around for loose wires/ vac leaks?

 

What's your idle RPM set at? If it's around 1,000 RPM, or higher, turn it down to about 800 RPM (fully warmed up).

Toyota has a program built into the ECU that cuts out the injectors when the RPM is above 1,000, the gas pedal is released, and the brakes are applied. They figured it would save some gas, and allow the engine to idle down faster when stopping. The injectors are cut until the idle drops below 1,000, then they're allowed to work again. If the idle goes above 1000 again, the injectors are cut again, and so forth.

Make sure the idle switch on the TPS is activating properly, and your IDLE RPM is below 1,000 RPM. Should actually be about 800-850 RPM. Make sure the filter on the dash pot is clean enough to allow air through, and that it functions properly. Make sure the aux air valve is functioning correctly, and is pretty well shut down once the engine is fully warmed up. Make sure the timing is set correctly. It should be 5° BTDC with the jumper in the test jack, and about 12-15° without the jumper in. Make sure all the cylinders are firing by hooking the inductive pickup of your timing light to the plug wires one at a time. If you get a flash, the plug is firing. Check all the plugs are clean and gapped properly, and that the distributor cap and rotor are in good shape.

Good luck, and keep us informed of how things go for you.
Pat☺

 

Thank you 2ToyGuy- I adjusted the idle and so far the truck has been behaving. My Idle was too low. Glad a Screwdriver is all that was needed.