Engine Run-On

[nogoodwithusernames]

So I got my engine installed in the car yesterday, and everything is going pretty well (messed up an oil line but that's a different story...) except the engine keeps running with the key shut off. According to another thread about this it should have shut off when I disconnected D+ on the generator (to the gen warning light) however this did nothing.
Also the first few seconds of idling the (I believe) fuel injection main power relay clicks on and off causing sync losses and rough idle but after a few seconds it stops and everything runs smoothly.
Once I get the little bugs fixed I can properly install the ECU under the backseat instead of on the cargo floor with all the wiring

[Clonebug]

You must have a back feed somewhere that is giving the MS unit power without the key on.

It's time to pull out the test light when the engine keeps running and find where that power comes from.

When my key is off I have one fuse box that loses all power and one that is fed directly from the battery.
The power "on" wire to the ecu gets cut when the key is off. The other one used to get cut too but I now feed it with continuous power.
The only time I had trouble with run on was when I tried a hard start relay. I couldn't get the engine to shut off.
I removed that relay and just made sure my wiring was in good shape to the starter solenoid.
I've never had any issues with start problems.

[nogoodwithusernames]

Ok thanks for the info, I'll check on that. For now I just put a switch inline to the "keyed" input on the relays. I think I want to move that directly up to the ignition switch if I can. Right now I'm running it off a relay under the back seat which I think is what is giving back feed.

[Ol'fogasaurus]

Engine run on aka dieseling can be caused by many things besides what Art talked about. I havent thought about it for many, many years so i did some looking so here is some things covering additional things to look at.

http://mgaguru.com/mgtech/engine/ro101.htm

[nogoodwithusernames]

Engine run on aka dieseling can be caused by many things besides what Art talked about. I havent thought about it for many, many years so i did some looking so here is some things covering additional things to look at.

http://mgaguru.com/mgtech/engine/ro101.htm

Ol'fogasaurus, I don't think it is technically dieseling as the ECU is actually staying powered up and supplying spark and fuel. The ignition wire turning the relays off and on is the problem and I believe relocating it should solve the problem. Hopefully I will have time this weekend to get that done.

Also got the car out of the driveway and around the block and back into the driveway without having to push it back! Time to get tuning

[Ol'fogasaurus]

I was just pointing out all shots covering run on. It used to be more common than it is now days so just-in-case! The hammering and jumping of dieseling isn't the only reason for or indication with engine run on. Granted, in this case stray electrons might be the problem but if you narrow or limit your search down to just that you could have a long search.

Years ago one of the guys I knew bought a car that had an off and on tendency to run on and it wasn't dieseling. They ended up rewiring the car, changing carburetion and many other things. He never did figure it out so they finally scrapped the car.

Anyway, what I posted may help someone else.

Sorry

Lee

[woodsbuggy1]

when I switched to MS, distributless ignition, I had the same problem, I had to install a diode in the charge wire. Where are you located? I have a bunch of diodes and would be happy to send you one. The online instructions for MSD cover this problem also.
Good Luck
Kenric