Hello,

Late last year I purchased a 1992 400e for my mother. Now the birthday present is kicking up a fuss and I need to fix it.

It's a lower mileage (140,000K) non ASR car. Originally purchased in Japan, imported by the original owner to Canada in the late 90's.

It has an intermittent idle/stalling issue.

Here's the key behavior.

1) after a warm restart it will often die when either putting it in gear or when trying to pull away from a stop. The idle seems low when this happens. If I keep a foot on the brake and maintain an RPM of 800 or better then it won't stall.

2) after a longer drive the idle will "hunt" dropping down to 400 and up as high as 900-1000

3) Occasionally it will only restart with the accelerator depressed.

4) other than the idle being low or hunting it does idle very smoothly which makes me doubt that it is an ignition problem

Is there a good testing procedure to isolate the real issue?

While the usual suspects seem obvious. (wiring harness, MAF, vacuum leak, dirty throttle body) I'm a bit clueless as to where the best place to start is.

The service manual points to replacing the MAF but I'd prefer to only do that if I am able to prove it is bad. Is there a reliable method for testing the MAF?

Thanks much in advance for any tips, clues or help you can provide.
Ian