1990 Toyota 4Runner

Reader Question: Good day,

I have a 1990 Toyota 4Runner 6-Cylinder automatic. Last week, I tried to start the vehicle but it would not keep going. Prior to this, I had no trouble starting it.

When you turn the key it will start, run for about 7 seconds, then it shuts off.

It will start it 30 times in succession, and do the same thing every time. It will start but shut off again after about 7 seconds.

I put in gas line antifreeze (there is gas in it), I have had the fuel filter and fuel pump replaced, but no difference, and it still shuts off after 7 seconds.

I live on Baffin Island in Canada’s north and a mechanic is very hard to find.

Any advice you can give me would be greatly appreciated.

Thank you very much for your time.

Craig

Hey Craig,

You really need to determine what is missing- fuel pressure or spark to the spark plugs. It could be either. I would first try and pump the accelerator pedal a few times during those 7 seconds the engine is running to see if that makes a difference.

If it does, you probably have a fuel delivery problem, like a bad fuel pump or the fuel pump is not getting power.

I am not 100% sure, but I think you have an MAF (Mass Air Flow) sensor on this engine. Starts then die complaints can be a common problem with a bad or dirty MAF sensor. Sometimes they can be cleaned with intake cleaner and the problem goes away.

Check out the bottom picture of the Beck Arnley model:

Picture of Mass Air Flow Sensor

A dirty throttle body could also cause erratic idle and dying at slow speeds and idle complaints. You can clean out the throttle body with intake cleaner and a toothbrush.

This is the only picture I have of a throttle body.

Picture of Throttle Body TBI Unit

It is easy to inspect and clean just to rule out that as a possibility.

I would also check for a vacuum leak under the hood somewhere. Look and listen for a hissing noise due to a broken rubber vacuum hose or hose connection.

Other than those ideas, I would just be guessing, and electronic parts for a Toyota 4Runner are usually not cheap.

Blessings,
Austin Davis