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Discussion Starter #1
Hey All!

My friend Reed and I (actually more him than me) are currently restoring my 1978 Spider - the question is, after I turn off the ignition and take the key out, the engine is still running. Does anyone know the reason behind this? I've been knocking Reed's head against a wall for the past several days ;)
 

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Does anyone know the reason behind this?
It means something is wrong... :p

I've been knocking Reed's head against a wall for the past several days.
Has it helped? With friends like you, who needs an enemy? :eek:
 

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Trained (ex)Professional, , 1953-2018 RIP,
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Heck of a diagnosis there Eric me boy! :rolleyes:

Ho-Quizzle,
Sounds like an electrical issue; a mis-wiring perhaps. Do you have a wiring diagram? If not, please send me your email address in a private message and I'll send you one.

And welcome to the BB!
 

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Discussion Starter #4 (Edited)
Clarification

Oops - seems like I've left something out, so, just to clarify:

Any HELPFUL and PRODUCTIVE response would be greatly appreciated ;)

Oh, and Reed's doing better now . . . it's only drywall and all . . .

Hobi Kwan Kenobi
1978 Alfa Spider
 

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But Mad North-Northwest
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Any HELPFUL and PRODUCTIVE response would be greatly appreciated
Okay, it means something is *really* wrong :D

Carbs or SPICA? I don't know if a SPICA will diesel, but carbs definitely can if you've got carbon build-up in the cylinders.

Could be a fried ignition switch as well. Multimeter should help tell you what's going on with that.
 

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It can be a bad ignition switch, but it can also be a stuck starter solenoid, or most commonly, an electrical feedback loop between the starter solenoid and the cold start solenoid, with is on the same Start circuit from the ignition switch. This is a fairly common problem with Spica cars, and can be solved by putting a relay in the circuit or moving the CSS wire as outlined in Wes Ingram's Spica book.

Andrew
 

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Key Off But Engine Still Runs

That's commonly called dieseling and it can be caused by a bad tank of gas or using old gas in a rebuild that has been sitting around also. It's not good for the car or the engine.

Pat would always have me depress the clutch with the car in gear, release it, and stall it to prevent the continued dieseling when it happened. In our case, I could literally walk in the house and it would still be "dieseling" away. It was caused by a bad tank of gas for us. Probably, my fault because I didn't always follow the rules about not filling up when the gas trucks were at the station. That was always his first question....

It's difficult, if the truck left just before I got to the station, how would I know? Am I supposed to keep a log of when the gas tankers show up at the stations I use. Geez, I'd never be able to work or do anything else since their schedule is so irregular.
 

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If the car has a carb, then yes it is likely due to "dieseling" (fuel injection cars do not have this problem because fuel is cut off - but I don't know about SPICA). The likely cause is auto-ignition of mixture (even in the absence of sparks). Yes, it could be a bad tank of gas but it probably due to not enough octane in the gas. With the momentum of the engine, fuel mixture get compressed and ignites by itself (higher octane gas would not self ignite as easily). This keeps the engine going and more fuel mixture gets sucked in through the carb so the engine keeps on turning!

Try some higher octane gas or retard the ignition advance a little!
 

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I think I misread; I was thinking key off but starter still turns. Sorry. If it's key off and engine keeps running, it's mostly like that the ignition circuit is not getting shut off. I personally have never seen a Spica car "diesel," but I suppose it's possible.

Andrew
 

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Key Off But Engine Still Runs

If the car has a carb, then yes it is likely due to "dieseling" (fuel injection cars do not have this problem because fuel is cut off - but I don't know about SPICA). The likely cause is auto-ignition of mixture (even in the absence of sparks). Yes, it could be a bad tank of gas but it probably due to not enough octane in the gas. With the momentum of the engine, fuel mixture get compressed and ignites by itself (higher octane gas would not self ignite as easily). This keeps the engine going and more fuel mixture gets sucked in through the carb so the engine keeps on turning!

Try some higher octane gas or retard the ignition advance a little!
I think this goes with the comment above about gas octane --- Pat always filled up half down and we had to keep track of what octane gas we put in the tank last time. He was a proponent of mixing the half-tanks, so if you put in 89 last time you put in 95 this time. I'm not sure those numbers are correct as far as octane ratings today, but you have the idea.

BlackAlfa said:
If the car has a carb, then yes it is likely due to "dieseling" (fuel injection cars do not have this problem because fuel is cut off - but I don't know about SPICA).
I don't know about the SPICA issue either. I do know that Pat was always taking SPICA pumps apart, but then we had a lot of SPICA cars.

FWIW, the worst Alfa offender of "dieseling" was the '73 Spider kamm tail. And even worse than the Alfa were the Mercedes and VW Dasher.
 

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It can be a bad ignition switch, but it can also be a stuck starter solenoid, or most commonly, an electrical feedback loop between the starter solenoid and the cold start solenoid, with is on the same Start circuit from the ignition switch. This is a fairly common problem with Spica cars, and can be solved by putting a relay in the circuit or moving the CSS wire as outlined in Wes Ingram's Spica book.
Andrew

Yup, been there - done that:). Kinda errie when it happens, isn't it. If you don't have one installed anyway, a battery cut-off is a good idea.
 

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Eliminating the ignition switch from the question is easy. Just unplug the 3 wire ignition switch harness underneath the dash rather than turning the key to shut the engine off. If the engine continues to run, then the problem is not in the switch.

Tim
 
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