DOUBLE RELAY FOR THE FUEL PUMP

Gotta love that wiring . . .
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ORFORD2004
Posts: 1120
Joined: Wed Mar 17, 2010 9:48 pm
Your car is a: 1983 PININFARINA
Location: Sherbrooke, Qc, Canada

DOUBLE RELAY FOR THE FUEL PUMP

Post by ORFORD2004 »

When i bought my car, the fuel pump was running when i turn the switch on because there was a wire connect from the fuse box to the + terminal on the pump.I remove the crimp and the wire and everything working fine. Yesterday, i try to start the car and as soon i move the AFS flap by hand, the inline 20A fried. If i connect only the white connector on the relay and move the relay by hand, i have 12V on the pump. If i connect the black connector and the white, when i push the relay, i got only 3V at the pump. Any idea what could be wrong? Is the double relay control anything else or just the fuel pump?
beachboy

Re: DOUBLE RELAY FOR THE FUEL PUMP

Post by beachboy »

I am not sure that I understand your question. When you removed the wire from the fuse to the pump, could you start it normally? You said everything worked fine. Then the next day it would not start?

The fuse should be a 16A fuse, not a 20A fuse. So there is a problem. The white wires from the relay control all the fuel injection parts, injectors, computer, sensors. The other four wire plug gets power from several sources and feed all the other items, including the white wires.
I think that it is possible that the fuel pump relay side of the dual is blown. Is it possible to borrow one from another Molson brother to see if that is the solution?
Make sure you have an electrical schematic for the spider to follow the wires to make sure the pump is correctly wired.

Good luck
ORFORD2004
Posts: 1120
Joined: Wed Mar 17, 2010 9:48 pm
Your car is a: 1983 PININFARINA
Location: Sherbrooke, Qc, Canada

Re: DOUBLE RELAY FOR THE FUEL PUMP

Post by ORFORD2004 »

The car was running whit the wire connected in the fuse box. Then i remove the engine and transmission for painting job.
but after removing the crimp on the starter switch, i was able to ear the fuel pump running when i move the AFS plate. Since then i did not change anything and now the in line fuse fried. So i think to cancel that double relay and put a switch on the wire from the fuse box.
ORFORD2004
Posts: 1120
Joined: Wed Mar 17, 2010 9:48 pm
Your car is a: 1983 PININFARINA
Location: Sherbrooke, Qc, Canada

Re: DOUBLE RELAY FOR THE FUEL PUMP

Post by ORFORD2004 »

I change connector for the injector. Maybe i switch the wire side. Is that important or it do not affect anything?
rlux4
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Joined: Thu Jan 10, 2008 8:32 pm
Your car is a: 1982 2000 Spider
Location: Granite Falls, Wa

Re: DOUBLE RELAY FOR THE FUEL PUMP

Post by rlux4 »

Whew. Where to start?
By AFS plate, do you mean AFM flap? If so, the normal operation of the fuel pump depends on the flap opening. This happens whenever the engine is turning over. The intake of air on the intake stroke causes the flap to open. You could bypass the dual relay and wire your fuel pump directly off the ignition switch, but you'd be doing away with a safety feature the dual relay provides. If the engine is not running, the fuel pump shuts off. This lessens the chance of an engine fire during a crash or ruptured fuel line.
Ron
Ron Luxmore
rlux2n2@gmail.com
'82 2000 Spider: after 26 years between Spiders.
ORFORD2004
Posts: 1120
Joined: Wed Mar 17, 2010 9:48 pm
Your car is a: 1983 PININFARINA
Location: Sherbrooke, Qc, Canada

Re: DOUBLE RELAY FOR THE FUEL PUMP

Post by ORFORD2004 »

I got a friend who have a 79 and i'll try is relay and ecu this weekend to see if the problem come from those parts
rlux4
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Your car is a: 1982 2000 Spider
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Re: DOUBLE RELAY FOR THE FUEL PUMP

Post by rlux4 »

His car is probably carb'd, unless it's been converted. FI came out on our cars in 1980 for cars imported to California and all cars in 1981.
Ron
Ron Luxmore
rlux2n2@gmail.com
'82 2000 Spider: after 26 years between Spiders.
ORFORD2004
Posts: 1120
Joined: Wed Mar 17, 2010 9:48 pm
Your car is a: 1983 PININFARINA
Location: Sherbrooke, Qc, Canada

Re: DOUBLE RELAY FOR THE FUEL PUMP

Post by ORFORD2004 »

Then it's maybe a 80 because it's a FI for shure
ORFORD2004
Posts: 1120
Joined: Wed Mar 17, 2010 9:48 pm
Your car is a: 1983 PININFARINA
Location: Sherbrooke, Qc, Canada

Re: DOUBLE RELAY FOR THE FUEL PUMP

Post by ORFORD2004 »

I just fix the problem. There was a short between the two wires on the auxilliary air regulator. And now, the car start. YES :D
rlux4
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Your car is a: 1982 2000 Spider
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Re: DOUBLE RELAY FOR THE FUEL PUMP

Post by rlux4 »

Good going! Hope you're having good weather to drive your running car.
Ron
Ron Luxmore
rlux2n2@gmail.com
'82 2000 Spider: after 26 years between Spiders.
ORFORD2004
Posts: 1120
Joined: Wed Mar 17, 2010 9:48 pm
Your car is a: 1983 PININFARINA
Location: Sherbrooke, Qc, Canada

Re: DOUBLE RELAY FOR THE FUEL PUMP

Post by ORFORD2004 »

I hope also but my interior is stil in LA for restoration. It's ready but if he can remove is finger from is noze and ship it to me, i'll be happy to finish my project
zachmac
Posts: 1278
Joined: Sun Aug 24, 2008 9:20 am
Your car is a: 1978 Spider [1979 2 ltr engine]
Location: Aiken, SC

Re: DOUBLE RELAY FOR THE FUEL PUMP

Post by zachmac »

ORFORD2004 wrote:I just fix the problem. There was a short between the two wires on the auxilliary air regulator. And now, the car start. YES :D
That makes perfect sense as the feed to the pump also feeds the AAV. If you had a short there you were "robbing" the voltage to the fuel pump.

BTW, a lot of folks don't understand that the power to the AAV is just for a heating element to cause it to close faster than it would without the electrical heater's assistance. The AAV itself opens and closes mechanically as driven by a bimetallic strip. The wires just heat up that strip faster than ambient engine compartment heat. If that wire is totally disconnected (open but NOT grounded) the car should still work fine but it will take longer for the AAV to fully close. Idle will be a little higher until it does get warm enough from engine heat to fully close the AAV. Not an issue in the summer but it could cause a high idle in the colder months, especially in the great white north!
Jeff Klein, Aiken, SC
1980 FI Spider, Veridian with Tan (sold about a year ago), in the market for another project
1989 Spider, sold
2008 Mercedes SL65
2008 S600 Mercedes V12
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