71 240z engine keep running after turn off

[dualies]

just did a major tune up, but now the engine will stay running for about 5-10 second after I turn the ignition off. Appricated any input.

[Zs-ondabrain]

Is it Deisel'ing or just running as if you did'nt even shut the Key off? If it's deiseling, go with a higher Octane fuel and retard your timing a little.

If you did an alternator upgrade (280ZX alternator upgrade) and did'nt use a diode or My ZXP adaptor, it'll keep running cause the alternator is supplying the ignition with power from the lack of the diode.

The other possibilities are sticky ignition switch or bad diode in your Voltage regulator. Wiggle the key after shutting the car off to see if it's the switch. If not, replace the Voltage regulator and see if that works.

Good luck and let us know how it turns out.

Dave.

[dualies]

Hi Dave, Thanks for the good work on the wiper deal, I got both of your kits, now my 71 is finally ready, I will put the kit in very soon. as far as my 71, it is defintely "Deisel'ing" no I did not do a alternator upgrade, it still stay stock,

I will try all it after the holidays. Thanks and wish you have a happy Happy New Year.

[Zs-ondabrain]

Like I said, Higher Octane fuel and retard the timing a little. That should do it.

Let us know what happens.

Dave

[JonnyRock]

I've run into this twice now on my '70.

I assumed it was because of the diaphram that prevents the throttle from closing for several seconds after you lift your foot off of the gas.

But next time I fill up, I'll put a higher grade in her and see if it happens again.

[dualies]

Had a radiator removed and flushed, the the whole cooling flushed, use the highest octane gas, change the fan clutch, engine runs cooler, now the problem is gone.

[MrZ]

try to check the timing. I did encounter the same problem and was solved by a timing light.

might help.

[sblake01]

Why? He said the problem is gone over a month ago.