Worked on O2 wires, now no fuel pressure

[Paul Workman]

Originally Posted by Funracer1

Update:

I did the fuel pump test today as described here:

http://www.zr1.net/forum/showthread....hlight=amperes

My DVM showed 5.37A draw steady. I guess this indicates 1 pump
running and 1 not or very weak. Fuel pressure at the Schrader valve
during the test was again zero. I have not been able to test the guage
yet on another car but when I push the Schrader valve nothing comes out. Obviously there is no pressure in the rail.

What now?

Thanks

Well, I'd say that confirms you have one pump not running. Next question: Are you getting voltage to both pumps at the (tank) connector? If not, then you may have a fuse blown on one or the other pump, OR a pump is bad. AND, you have no pressure...Bad pump (again) or a fuel line connection.

Don't get discouraged. It's all very logical.

When I taught network troubleshooting, this is the set of rules I used to teach; works on everything from your car to your toaster oven! You can take this with a grain of salt, but I find this works, even if you have never worked on a piece of electronic equipment before.

Troubleshooting Rules:

1. Know how the system works (a schematic helps a lot)
2. Nothing taken for granted: Take measurements! What is the reading? What should it be?
3. Logical progression...NO SHOTGUNNING (i.e., changing parts till the problem goes away...)
4. Divide and eliminate!

Maybe this will help someone out there??

P.

[Funracer]

"Well, I'd say that confirms you have one pump not running. Next question: Are you getting voltage to both pumps at the (tank) connector? If not, then you may have a fuse blown on one or the other pump, OR a pump is bad. AND, you have no pressure...Bad pump (again) or a fuel line connection"

But I have one pump that IS running and still no FP. I think
its time to pull the pump assembly again.

Thanks

[Paul Workman]

Originally Posted by Funracer1

"Well, I'd say that confirms you have one pump not running. Next question: Are you getting voltage to both pumps at the (tank) connector? If not, then you may have a fuse blown on one or the other pump, OR a pump is bad. AND, you have no pressure...Bad pump (again) or a fuel line connection"

But I have one pump that IS running and still no FP. I think
its time to pull the pump assembly again.

Thanks

One pump running, no fuel pressure. Hmmm.... Quite a coikeedink when all this started with O2 wiring. Ah, well. One thing at a time, I recon.

Just for grins, you can bring a wire from the battery to the fuel pump connector and test both pumps at the connector. that is easier than taking hush pannels off to check fuses anyway. However, the pressure (or lack there of) when one pump is running is intriguing too. I agree...pulling the pumps is a given. (Wish I could be there to help ya. BTDT once myself; that is a dual pump failure scenario. Just gotta deal with one piece at a time. "Divide and eliminate", in other words.)

Good luck!

P.

P.

[Funracer]

"One pump running, no fuel pressure. Hmmm.... Quite a coikeedink when all this started with O2 wiring. Ah, well. One thing at a time, I recon"


Yes it is. However.......my Z project prior to working on the O2 wires
was replacing both fuel pumps. I originally thought this problem was related to whatever I was doing immediately prior to the issue cropping up. Now I think maybe it is my fuel pump work at fault.

We shall see. Unfortunately cannot get to it till next week.

Thanks

[Funracer]

Found it!

Pulled the pump assembly and found
the pump outlet line disconnected from the pump.
Reconnected and added a zip tie backup and car started
immediately after reassembly.

Now on to tracking down my idle problem.

[Funracer]

Just an FYI for anyone trying to pull and reinstall the fuel pump assembly.
Taking it out takes a few minutes.

As I stated in an earlier post above, it took me about 2 hours to
reinstall the pump assembly after changing the pumps last fall. I just
could not figure out how to rotate and angle it back into the tank.
I think it finally went in by accident.

This time, after an hour I finally figured out the trick.

The float switch hangs at the very bottom of the assembly.
It seems if you look at it that you should begin by lowering
the float switch under the right lip of the tank opening and
then work it down into the tank from there. Unfortunately
if you start that way the assembly will not fit unless you bend
something and force it.

If you begin by hooking the float under the left edge of the
tank opening and then lower and turn clockwise from there
it pretty much just drops right in. It lowers the frustration
index considerably.

Regards

[captcorvette]

I really like success stories that have an ending, explanation and photos. Helps those of us who posses limited knowledge and ability. Thanks for confirming the source of the problem.

[tpr60]

Haven't had to pull the pumps yet, thanks for the trick to install.