I have a 98 502 mag efi that sometimes will stay running after turning off the key. I have pulled the safety lanyard and still no luck. I have had to pull the coil wire to shut it down. This only happens once in a while, I checked for loose connections but still no luck does anyone have any sugestions or is this thing haunted any feedback would be helpful.

If it were a 1968 loaded with hours and crud and using cheap gas then I would say it is dieseling, but with such a new engine it is probably something in that crazy EFI system.

Might want to check the ignition switch for corrosion build up. If the contacts in the switch still make contact could keep the motor running.

Sounds like it could be a sticking ignition power relay. Next to the ECM there are two relays. One is the fuel pump relay and the other is the ignition relay. The ignition relay has two red, one pink and one black wire. Next time it happens, check the pink wire for 12V. If there is power there, the problem is the ignition switch, if not it's the relay. Maybe try tapping on the relay to see if it releases.

Dave

Dave,
That sounds like it could be the culperate, hopefully I will be splashing in a couple of weeks and i'ii check it out. Thanks for your help.

even if it was in the ignition switch wouldnt/shouldnt the lanyard kill it? i would think so.....

boatn70,
You are right, if it were the ignition switch, pulling the lanyard would kill the engine. Pretty much has to be the relay.

Dave

What was the final story here, what was the problem?

Thanks

Pismo,
Because of the beautiful michigan weather I have not been able to get the bottom wet. hopefully in a couple of weeks I'll be able to give you guys an answer.

i had the same problem, the alt. was bad, the alt. was shorting out and the batt. was keeping juice to engine so you could not shut it off.