Engine won't turn off

[Spiderinmlnj]

So I have created a new problem on my 82 spider.
It won't turn off.

If i turn key to run and don't start the engine then turn off then radio, lights,.... All turn off.
If i start motor and then turn key off everything keeps running until i stall the engine at which point everything turns off.

This is what i did to car today and i'm thinking something in this sequence caused problem as it was turning off fine 2 days ago.

1) in cleaning off top of oil filter i did short across alternator posts as i dre my arm out and rubbed it with my watch - interesting sparks - and yes i should always disconnect battery and tomorrow i will install quick disconnect on ground wire

2) cleaned off ground terminals on the two "bottle caps" on fender wells

3) lowered relay panel to check voltages on wiper delay timer to try and diagnose wiper problem.

At end i thought i should make sure car still started
That was when i found problem

Thanks as always for any guidance

Geoff

[azruss]

i suspect the problem came from shorting the alternator.

[spider2081]

I believe you could Isolate problem to a shorted diode in alternator by doing the following.
Start the car and then turn the key off.
If the car continues to run pull the small wire on the spade terminal off the alternator.
If the car stops running I believe you have isolated the problem to a shorted diode in the alternator.
Let us know what you find

[Spiderinmlnj]

Still keeps running with that wire pulled off.
Anything else you would suggest checking?

Geoff

[124JOE]

ignition?joe

[Spiderinmlnj]

So after spending some more time tracing the issues this is what I have found.

With switch off pink wire on the ignition coil is 0 volts - turn switch on and it goes to 12 volts - this is as it should.
So looking at wiring diagram pink wire out off ignition switch goes to fuse 1 as well as ignition.
Pull out fuse 1, start engine and turn key off - engine stops.
So I'm thinking there is voltage coming back through this fuse when the engine is running.

Maybe this is alterantor plus wiring changes by a previous owner.
Looking at the back of ignition switch revelas some creative wiring:-(

Geoff

[azygoustoyou]

I'd say that's a car that needs a longer cruise. You didn't wear it out yet. Get back out there and ride.

[124JOE]

test the coil with key off/on

[Spiderinmlnj]

Ok - real beginner question now.
How do I test the coil?
By on - do you mean key in on position and without motor running?


thansk for your help
geoff

[124JOE]

yes just testing for 12 volts at the coil

with it on then off
if it has 12v while off then you need to track the juice down .joe

[Spiderinmlnj]

Well I'm getting closer (or maybe farther away) to finding the problem.

With engine off and key off no voltage to the coil.
With engine off and key on 12 volts to coil.

With alternator disconnected engine won't turn off - so this should rule out alternator.

Pull fuse A and engine turns off as it should.
Put fuse A back in and pull blue / white off of fuse A post - engine does not turn off as it should.
Put blue white back on and pull white off of Fuse A post - engine turns off as it should - so this looks like something on this line.

Looking at Artigue wiring diagrams white only goes to stop light.
On my car jsut off the fuse box there is a blue plastice clamp that is clamping together white wire with a green/black wire.
Again looking at Artigue wiring diagrams:
- green black from throttle plate swtich to ECU - could this be problem (not sure why it would be evne neatr the fuse box
- green black for high beams wired into fuse 3 - ok this looks like next one to pull out
- green black on fuel pump - fuel pump on this vehicle seems to turn on when key turned to on and not waiting for the engine to be started - is this normal?
- green / black on washer pump - possible but not sure why it should come into play.


Any other suggestions are welcome.


Geoff

[Danq]

Geoff,
It sounds like there is a short to 12v from the downstream side of no 1 fuse. The short is suppling the coil 12v when your ignition switch beaks the circuit.
Fuse number 1 protects the seat belt delay relay, which is located on the relay board. My guess is the seat belt delay relay is feeding 12v back to the coil. Pull the relay board and see if there is damage to the wiring or maybe the relay is toast

The fuel pump should not be running until there is air flow in the air flow meter. A different problem not related to this.

Hope this helps. cursed electrons, cann't see'em cant trust'em but can't live with out 'em

[Spiderinmlnj]

So I think i have found the issue.
When I disconnect C19 i still get power to fuel pump and the engine shuts off normally.
Based on this my theory is:
- there was a problem with relay controlling power to fuel pump ( or perhaps another piece in that part of circuit)
- PO got around issue by powering fuel pump off white wire off of fuse 1
- my cleaning / fiddling with relays and ground connections cleared that problem ( at least for now )
- now the fuel pump power also gets fed back onto whit wire off of fuse 1 once engine is running and when key is in off

So sort term solution could be to leave C19 disconnected but thinking long term i should separate the circuits like they are supposed to be.

Does this make sense?


And thanks for all the advice along the way.

Geoff

[rlux4]

As Danq stated, the fuel pump shouldn't run until the engine is turning over. This pulls air in past the flap in the AFM which closes a contact and sends a signal to the dual relay, which has already gotten 12V from when the key is turned on. These two signals close the contacts in the dual relay and the 12V is sent to the fuel pump via a green wire with a black stripe. You can leave the dual relay bypassed, but the factory set up the original system as a safety feature. If the engine stops, in a crash for instance, the fuel pump shuts off because there's no air flow through the AFM. Time was these cars had a reputation for engine bay fires and this safety feature is a good idea IMO.
If you want to get the wiring to the fuel pump correct again and don't know how, let us know and we'll explain the wires involved.
Ron

[Spiderinmlnj]

Ron

Thanks for reply / advice.

Fixing the wiring should be a five minute fix and that is the way i will go.
Then i just need to hope the original problem doesn't return.
Is it common for the relay that controls the fuel pump to go bad?
I'm thinking may be worth replacing it as a preventative measure.


Geoff