Fuel Pump Failure?

[Ryan King]

So Long Story short...

My brother and I were doing a cross country road trip to Pennsylvania. I decided to take the DeLorean off the car trailer so I could drive it for awhile on our way into Arizona. We hit some really bad road construction, and the road got REALLY bumpy. As I was trying to pull into the next lane to avoid it..my car died.

I pulled off the freeway and the car wouldn't turn over. So I turned the key off, and turned it to AUX. I couldnt hear the fuel pump prime. So I got into the electrical compartment to inspect the fuse box. Fuse #7 was melted through the fuse box (Fuel & LAMBDA). My box has already been replaced once before. So I ended up cutting an inline fuse off of my alarm system and tried that...still no fuel pump prime.

I then tried to do an RPM relay jump with a paper clip...also no luck

So I emptied my trunk and got under the fuel pump cover. I found that my boot was completely filled with fuel. The fuel pump was completely submerged in fuel. My guess...the fuel in the boot made the pump short out? I also noticed that the fuel harness was really squishy and rubbery from the the fuel as well.

As of right now, the car will not start. My inertia switch is fine, although I have yet to check the wiring. My plan as of now is to remove the fuel pump. My question is is it normal for the boot to be filled with gasoline? Could that have made it short out? I also plan on trying to putting a better inline fuse then the one I have now in the fuse box. And try swapping out an RPM realy with a friend of mine...

Let me hear your ideas..as of right now I am at a dead end. :/

/end rant

-Ryan

[sdg3205]

Hey Ryan

That's a bummer. Did you test for 12v at the fuel pump? If you see 12v but no pump action I think you've got your answer.

Keep us posted!

[Ryan King]

Hey Ryan

That's a bummer. Did you test for 12v at the fuel pump? If you see 12v but no pump action I think you've got your answer.

Keep us posted!

Thank you for the swift reply. So I could just hook the harness up to a 12volt battery? Or do I just need to wrap standard wire around it?

Is it common for the boot to be filled with fuel?

[sdg3205]

Well, first and foremost, be careful.

I'd remove the fuel pump from any gas and fumes if possible. Ive never seen a volt meter spark or arc, but better safe then sorry. If you want to be super careful you could always unplug the pump at the harness and measure voltage at the prongs.

I'd put your meter across the points on the pump with everything in stock configuration first, with the ignition at it's normal place (Aux 2) as if the pump would prime normally - so no jumpers or anything. Now measure for voltage.

If you dont see anything, try jumping the RPM relay and see what you get.

[Ryan King]

Well, first and foremost, be careful.

I'd remove the fuel pump from any gas and fumes if possible. Ive never seen a volt meter spark or arc, but better safe then sorry. If you want to be super careful you could always unplug the pump at the harness and measure voltage at the prongs.

I'd put your meter across the points on the pump with everything in stock configuration first, with the ignition at it's normal place (Aux 2) as if the pump would prime normally - so no jumpers or anything. Now measure for voltage.

If you dont see anything, try jumping the RPM relay and see what you get.

Are you talking in regardsd to a multi-meter?

[sdg3205]

Are you talking in regardsd to a multi-meter?

Yes sir!

[Bitsyncmaster]

The fuel on the pump would not cause the pump to fail. Yes be careful probing around with power (RPM jumpered) at the pump.

The jumper at the RPM relay should run the pump always.

Since your fuse melted my guess is your pump has frozen and your drawing to much power which melted the fuse. But not enough power to blow the fuse.

[content22207]

If your pump is OK, the fastest and easiest way to limp the car home is to run a 12v wire from the door lock circuit breaker, out the passenger door, under the hood, behind the pump cover, to the pump. Door and hood weatherstripping will not damage the wire.

You can do the same thing on the ground side in the other direction to the passenger seat belt receiver bolt (bolts directly into the frame and isn't rusty). Just strip back a bunch of wire and wrap it around the receiver a few times.

Most Bosch pumps have eye terminals so you won't have to cut into the factory harness.

Bill Robertson
#5939

[stevedmc]

My question is is it normal for the boot to be filled with gasoline?

When I first got home with 16510 I kept smelling a fuel smell. Well, I had the same problem. The fuel pump boot was not sealing around the fuel pump and the top of the fuel pump terminals were covered in fuel! It is not supposed to do this.

Either your fuel pump boot is loose or it is gummy due to the effects of ethanol. If it is loose inspect the clamp that wraps around it. If the clamp is bad go down to Orielly's or Autozone and get a new stainless one. If the boot is gummy call up your vendor of choice and get a new boot. I believe they sell for $50 or $60 and all vendors get them from the same place now.

[Ryan King]

I still can't seem to figure out what would have caused my Problem to begin with.

[Bitsyncmaster]

I still can't seem to figure out what would have caused my Problem to begin with.

If your pump is shot probably it was ready to go and the bumps made it happen.

If the pump is good probably your fuse was making marginal contact. But you said you have a new fuse block so that's unlikely.

Maybe the bump moved the pump but that should not have damaged the pump.

A bump may have opened the impact sensor but that would not have caused the fuse damage.

[DeLorean]

The fuel leaking from the fuel pump was likely a separate issue from the fuel pump itself no longer functioning. How does your fuel pump boot itself look? I know mine is cracked and leaking (I have a new one on order) - also the O-rings that the banjo bolts seal on can frequently leak and so can the lines themselves. A very small leak (a drop every few seconds) can accumulate in that boot over a period of time.

Check for power to the fuel pump, number one. If there is no power, do further investigation as to why it's not getting power.

The old Bosch roller fuel pumps like the DeLorean has can be frequent source of problems when they get older. I have seen them start to draw more amperage when they get older which can over tax the fuel pump relay or the fuel pump fuse getting them hot to the point that they fail. Also, sometimes the pumps can lock up internally. If this happens, they will still draw amperage, but won't run and just get hot. There is a real possibility of a fire with this sort of a failure if the car were to sit in "on" with the fuel pump relay jumpered. Typically with the car sitting in "on" and their being no RPM signal the fuel pump wont run, but the "paperclip mod" would allow this to happen. Also remember when checking for power at the fuel pump, this must be done when cracking the car. If there is no RPM signal, the fuel pump won't turn on.

Oh also if you have one of these "locked up" bosch roller pumps, you can sometimes strike it with a hard object to get it to work again and get you down the road, but this is by no means a permanent fix.

[Bitsyncmaster]

Oh also if you have one of these "locked up" bosch roller pumps, you can sometimes strike it with a hard object to get it to work again and get you down the road, but this is by no means a permanent fix.

Running the pump backwards sometimes will fix it. But I would not leave that pump in the car any longer than the drive home. You run it backwards by powering reversed.

[Ryan King]

What's weird is I had only been driving the car for about an hour. But it was in hot 100+ degree weather. So combined with that and the serious bumping...it seems like that's what killed it. I will pull the pump and test it as well as put on new copper washers. As for the fuse box. Can I just run a new in lune fuse and not replace the box? Solder and shrink wrap it?

[tiger38117]

Check the connection where the pump plugs in to the harness. My car died suddenly one day and I finally discovered the problem was that plug not having a solid connection anymore. Bent the female end to grip the male end more tightly and it was fixed. This could easily be caused by hitting a bump.

[Ryan King]

Check the connection where the pump plugs in to the harness. My car died suddenly one day and I finally discovered the problem was that plug not having a solid connection anymore. Bent the female end to grip the male end more tightly and it was fixed. This could easily be caused by hitting a bump.

You won 1,000 internets. This seemed to be my problem. So I tightened it up a bit, and wrapped the harness in electrical tape to help prevent any play. Thanks everyone for your input!

[tiger38117]

You won 1,000 internets. This seemed to be my problem. So I tightened it up a bit, and wrapped the harness in electrical tape to help prevent any play. Thanks everyone for your input!

What's the cash value of one internet?

[sean]

What's the cash value of one internet?


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