Engine will not shut off after engine swap.http://www.jalopyjournal.com/forum/images/

I did an engine swap, went form a '54 baby HEMI, to a '59 POLY. I got it running today. It purrs like a pissed off kitten. It started right up but, it doesn't turn off. I wired it up like it was before. Its gotta be something simple, I just cant put a finger on it.

I converted the car from 6V, positive ground to 12V negative ground. The only thing that has changed beside the engine, is that it has points instead elec. ignition.

Any ideas of what I could have overlooked?

Thanks in advance.

Art.

 

With it running disconnect the alt output. If it stops then you have a feedback. Check switch side of the coil for power with the switch off.

 

With it running, I disconnected the alt./field wire. It kept running till I turned off the key...

Checked the + side of the coil with the switch off, no power there.

What is a feedback? And what fixes it?

Thanks for your help and responding so quick.

Art

 

GM alternator?

 

No, Mopar 12V generator and regulator. Eventually going to alternator, unless that is my issue, then I'll go to Alt asap.

 

Had to put a diode in the alternator field wire on my Chevy to stop this from happening to me.

 

Do you have a electric fan? Those sometimes will act like a generator keeping power in the circut. A backfeed is power feeding back from another source making something else keep working . Very strange that you have no power at the coil yet it still keeps running. You use a volt meter to check the coil or what? If using a test light disconnect the wire from the coil to test. Backfeeds are very common when using a GM alt without either a idiot light or diode.

 

My guess is the generator is feeding the coil , you will need to figure out where.

 

I didn't need a diode before, Chevydude. I shouldn't need one now. Everything is wired the same as before.

I'm thinking its something simple I overlooked, or something died while it was not being used.

 

I don't think he checked - engine running key off. It's obvious that if its staying running in key off that the coil wire is hot.

Most gm alternator plugs have the diode right in the OEM plug. Same thing with AC clutch plugs and E fan plugs.

 

Trace the coil wire all the way back to the battery, thru the switches and everything else, did you add any relays ? Something spinning is creating enough power to keep the coil wire hot.

 

No electric fan, in fact, I just picked one up yesterday but haven't installed it yet. The POLY is more than 2 inches longer than the HEMI. Therefor, the fan would hit the radiator. So, I will be running one.
I misunderstood, I checked the coil with the key and the engine off. And I did use a light.
I am not running a GM alt.

 

I did not add any relays.

 

OK, checked positive side of the coil, key off, still running, and yes, there is power at the coil.

Also, I have a ballast resistor, but it was there before, the issue came up.

 

Well if the points are closed the light usually won't light ,it's about the light has more resistance then the closed points. As I said disconnect the switch side coil wire Then test with the light with the switch both off and on. You have to be getting power to the coil from somewhere. A pinced hot wire making contact with the coil power supply wire or ???

 

another thought is the resistor getting power from a terminal on the solinoid? If so disconnect that wire and see what happens. Is this a different starter than what was on the first engine?

 

Regardless of whether or not you needed a diode or resistor before you are experiencing feedback from the alternator. My flathead ran fine for months and suddenly one day it wouldn't shut off. It doesn't take much to keep the ignition going.

You did say you went from 6V to 12V, so you did change something in the electrical system. The feedback is usually taken out by an idiot light in the circuit, that's how little amps it takes to keep the engine running. Google alternator feedback and see where to put either an idiot light, (basically a resistor) or a diode. It's a simple splice and it will go away.

 

I'm running the starter from the poly I picked up. The other starter didn't have matching gears for the ring on the torque converter I'm using.

An other thing I noticed, the engine starts and shuts off, like it supposed to, with the wire that goes back to the field on the regulator, disconnected.

The more I try to figure it out, the more confused I get

 

DIAVOLO : Ya need to read all of the posts ,he is runnng a GENERATOR!

 

Sounds like either a misconected wire or a pinched wire that is getting or giving power to another. Isolate one thing at a time and see what cures the prob. Like disconnect all the wires from the gen and try it ,no change then do the same to the regulator. When you find what system/unit is causing the prob then check very carefully the wires attached to that part.

 

Diavolo, I went from 6V to 12V when I got the car 6 years ago. I had to, the wiring was shot. I was afraid it would catch on fire, it was so bad. I never had this problem for the last 6 six years.

Why would I need that now. I don't think that's dealing with the real issue. Someone else suggested the same thing only they're running a GM alt.

 

Ok J.E., I'll try the old isolating the problem trick. Thank you. I was hoping for an easy fix or maybe something I forgot to do, but it might be better to go through it all make sure its all well.

 

Isolating the problem IS the easy fix.

 

http://www.jalopyjournal.com/forum/showthread.php?t=817052

Another thread with a generator issue. Look at post 7.

It doesn't matter if it's an alternator or a generator, the ignition is getting juice from feedback regardless. A resistor or a diode would solve the problem.

If you read the link I sent it's someone with a problem with 12V generator and apparently the same problem. Post 7 is the most agreed answer.

I will again state that my car would shut off just fine for a good long while. One day it decided there was enough feedback to keep the ignition powered and I solved my problem with a diode. Maybe in your case check the link I provided and see if that's a better solution for you.

Final post, it worked for him

"The 54 ignition is 4 posts.
Moving the wire to acc post did the trick.
No diode or idiot light.
Thanks fellas! "

 

Sounds like the ballast by pass wire has been connected to power at the starter

 

That should also show power to coil with key off & engine off.
From what I gather it sounds like R&R daddy has power to coil with key off engine running. The easiest explanation is a back feed from some device generating current while in motion.

What's puzzling is how the coil wire is tied to the rest of the electrical system.
It should go from ignition switch to the coil in a direct path, obviously it is not the case. When the ignition switch is off, it should also stop the current to the coil because the only supply connection or distribution to the coil is from the ignition switch.

 

I guess I should close this with a conclusion.

The problem was the regulator. I "isolated" the problem. I didn't polarize the regulator after disconnecting the battery and I think that's what did it. I went to the junk yard, got a like new GM 75 amp alt for $15 during their 1/2 off sale. Problem solved

 

There is something strange about this. There are two wires that connect to the positive terminal on the ignition coil. 1) current from the normally open terminal on the ignition switch that is closed when the ignition switch is in the start position. 2) current from the normally open pole on the starter solenoid that closes while you are cranking the engine over. That wire assures full current to the ignition coil due to the starter consuming a large amount of current.

I fail to comprehend how the charging system was supplying current to the positive terminal on the ignition coil when both of the normally open switches were normalized. There can only be one logical explanation for your problem? You have a hot wire connected to one of the normally open terminals. If it is on the normally open starter solenoid terminal then you are defeating the ballast resistor.

McGurk

 

Are you sure there's not power to the coil all the time with the switch off? Sense it's a new combo.

 

That's what I would say too.

Try disconnecting the bypass wire.

glad you found the prob