Hey everyone. Is there any particular "good" reason why the PO of this '82 2000 would bypass the fuel pump relay and wire the fuel pump straight up to the ignition switch, sharing the same pin as the ignition coil? They basically jumped the green/black wire that goes to the fuel pump from the relay, straight to the run circuit on the ignition. Here's some pictures..... maybe someone can take a crack at it:
Here's the lovely job they did patching it to the ignition harness that I just eliminated:
Obviously, I want to fix it right, but I'd like to know the scenario I am dealing with first. I've got the battery disconnected and I'm addressing several terrible solutions that happened to this poor car right now.
Fuel Pump hot wired to ignition switch.
- kmead
- Posts: 1069
- Joined: Sat Aug 02, 2008 9:24 pm
- Your car is a: 1969 850 SC 1970 124 SC 85 X19
- Location: Grand Rapids, MI
Re: Fuel Pump hot wired to ignition switch.
It should definitely be through a relay. Taking as much load off the switch as you can will allow the switch to live longer. It is a weak spot and the new replacement ones are not as good as the OEM version.
Whenever possible I like to go back to the original or improve on the design of what was done before. Depending on what the previous owners did, you may have a non fused condition.
Whenever possible I like to go back to the original or improve on the design of what was done before. Depending on what the previous owners did, you may have a non fused condition.
Karl
1969 Fiat 850 Sports Coupe
1970 Fiat 124 Sports Coupe
1985 Bertone X1/9
1969 Fiat 850 Sports Coupe
1970 Fiat 124 Sports Coupe
1985 Bertone X1/9
Re: Fuel Pump hot wired to ignition switch.
Oh it's definitely not fused. I'm just hoping the relay isn't bad. Guess I'll find out tonight! I was just wondering more or less if it's anything someone has done for any reason specifically.
Re: Fuel Pump hot wired to ignition switch.
You may find that the relay is not working. Or you may find that the pins relating to the AFM readings on the ECM are not making good connections. The PO may have hard-wired it to bypass a problem in the system that he didn't want to face, or didn't know how to address.
You are absolutely right that it needs to be fixed correctly. The fuel pump should not run when, for example, there is no signal made by the AFM that air is flowing through the intake. With the pump hard-wired to run any time the ignition is on, you risk getting fuel when you shouldn't.
You are absolutely right that it needs to be fixed correctly. The fuel pump should not run when, for example, there is no signal made by the AFM that air is flowing through the intake. With the pump hard-wired to run any time the ignition is on, you risk getting fuel when you shouldn't.
Re: Fuel Pump hot wired to ignition switch.
There are some really good fuel injection diagnosing/troubleshooting/maintenance guides available online. As the pump system, including the relays and the electronic control module, the air flow meter and the pump are all integral to this system, that's where you want to go to get a good overview and go through the steps.
Here's a good start, probably the easiest to read and digest, but not as technical as the Bosch guide, for example:
http://www.hiperformancestore.com/Ljetronic.htm
Here's a good start, probably the easiest to read and digest, but not as technical as the Bosch guide, for example:
http://www.hiperformancestore.com/Ljetronic.htm
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- Patron 2022
- Posts: 4211
- Joined: Thu Jan 10, 2008 8:32 pm
- Your car is a: 1982 2000 Spider
- Location: Granite Falls, Wa
Re: Fuel Pump hot wired to ignition switch.
It is very common to find that a PO has bypassed the dual relay to get power to the fuel pump. Usually it's because they didn't diagnose the cause of the pump not running. If the green wire with a black stripe at the dual relay doesn't have 12V when the car is cranking it could be a bad dual relay, but it's more often than not that the dual relay isn't getting the 12V from one of the (4) sources. Here's a good trouble shooting guide to check for the problem once you've taken out the hot wire and made sure the original wiring is in place:
http://www.wcmotors.com/personal/Fiat%2 ... agnostics/
Ron
http://www.wcmotors.com/personal/Fiat%2 ... agnostics/
Ron
Re: Fuel Pump hot wired to ignition switch.
Gentleman, I thank you kindly. I'll troubleshoot and report back later! This is what I do instead of sleep these days.
Re: Fuel Pump hot wired to ignition switch.
Alrighty. I finally got the time to mess with this. After rewiring the ignition switch properly, and fixing two spots on the fuse block that were twisted together, the car appears to work normally... except the wipers don't work. I'll address that tomorrow.
- ga.spyder
- Posts: 3478
- Joined: Tue Nov 06, 2007 7:19 pm
- Your car is a: 1982 Spider 2000
- Location: Blairsville ,Ga.
Re: Fuel Pump hot wired to ignition switch.
Ron Luxmore to the rescue...again.He diagnosed mine ,with the same issue, and helped me fix it over the phone!
Craig Nelson
1982 Spider 2000...pride and joy
1981 Fiat X1/9..gone but not forgotten
1976 124 Spider..the self-healer
2001 BMW 328ci daily driver and track car
Fling It Around Turns !
1982 Spider 2000...pride and joy
1981 Fiat X1/9..gone but not forgotten
1976 124 Spider..the self-healer
2001 BMW 328ci daily driver and track car
Fling It Around Turns !