Fuel pump issue

[o2bgitarn]

Hello, the spider I recently purchased had a wired McGyvered by a prior owner from the fuse panel directly to the fuel pump with a toggle switch to turn the pump off and on. I removed the "hot wire" job and put the original wiring back to the starter. When I turned the ignition and cranked the engine over I did not hear the pump engage and the car would not start. I rigged the "hot wire" back up and the pump came on and the engine fired right up so I am assuming either the wire harness is compromised or the ignition switch might be bad as it is not sending power to the pump? Has anyone had a similar issue or can suggest a possible solution. I really would like to get it back to original. Thanks

[bobplyler]

Is it EFI or carb?

[o2bgitarn]

The car is EFI....thx

[spider2081]

I suggest you join Mirafiori.com chat room. This chat room has a library available for members. I really like the Fiat Publication titled: "Spider 2000 Electrical Diagnostic Manual 1980-1981" This manual contains information that applies to all cars regarding electrical troubleshooting even though it specifically addresses the 80-81 Spiders.

It would also be helpful to you in identifying the type of connectors and pins you are looking for in your other post.

[o2bgitarn]

Thank you spider2081 I will check it out. Cheers

[Hughster2003]

Thank you spider2081 I will check it out. Cheers

Thank you spider2081 I will check it out. Cheers

[Hughster2003]

just got a 1980 fuel injected spyder with the same McGyver hook up.. I took switch off and now no fuel pump , the fuse is still wired so it has been spliced after the fuse.. Is the fuel pump supposed to be on with the ignition is on but before the starter is activated? The fuse is only hot if started is activated for the fuel pump? Last major thing to get sorted out with car. Help

[spider2081]

the fuel pump fuse in a FI car should have power on it all the time. It usually has brown/white wires on both ends.

[RRoller123]

Timely post. Mine just gave up the ghost. Fuel pump stopped running. Jumpered power to the pump, it ran fine. No power to the pump. So likely the fuse. The fuse holder in mine I think is original, it is a red 2-piece holder, tucked up into the rat's nest behind the fuse box. It requires threading in one end, which twists up the wires. But interestingly enough, the old style ceramic fuse which was in there had one end twisted off, so it was only barely making any contact. Explains why the pump sputtered before it stopped working. The twisting motion required to connect the 2 sides of this type of fuse holder spins the contact inside, wrecking the old style ceramic fuse end contact! Soldered in a new twist lock 1/4 turn type, with a glass barrel fuse, and problem completely solved. Just a little gremlin to be aware of.

Just an aside, on the FI cars, if you need to run the starter to turn over the engine for any reason, you don't want the CSI and the Injectors firing without starting. It WILL flood the engine after a few repetitions. There are a few ways to avoid this, but I have found the easiest is to just pull this fuel pump fuse. Then there is no pressure in the fuel rail and the engine wont flood while you are working on it.

[DRUMMOND]

The double relay sends power to the fuel pump via the AFM sensor. Engine has to turn over for the fuel pump to work. this is a saftey feature
A lot of people bypass this feature and do not spend the time getting it fixed properly. You can also test the relay by moving the flap inside the AFM with the ignition on this will start the pump.
It could be your fuse or the above problem
Safety First

[DUCeditor]

Just logged into share a similar story, but in my case on my `77 carbureted model.

Sometimes it'd start, sometimes it wouldn't. The problem was especially likely if the motor was hot.

What I found was that the pump was dead with the ignition on -- even with the starter cranking. But if it caught for more than a nano-second it ran flawlessly.

Cold starting has the advantage of the accelerator pump. A few quick jabs of the pedal was the norm and that squirted in enough fuel for it to catch. Hot, no. Then it was a matter of the little remaining in the bowl.

I, too (well actually Alex at AVA Restoration http://www.avarestoration.com/) cleaned the contacts and now, at least for now, the problem is resolved.

With the fuse "bad" the pump would run after the engine caught because the 'juice' would reach it from the alternator by what amounts to a back road.

Ain' old Spiders fun? No two quite alike. Especially the wiring!

-don

[RRoller123]

The double relay sends power to the fuel pump via the AFM sensor. Engine has to turn over for the fuel pump to work. this is a saftey feature
A lot of people bypass this feature and do not spend the time getting it fixed properly. You can also test the relay by moving the flap inside the AFM with the ignition on this will start the pump.
It could be your fuse or the above problem
Safety First

As many are, mine is wired to run with the ignition on, which I like. And I put an inertial shutoff sensor on the rear trunk wall, for safety in the event of an impact.