Car just quit???

[dmc3130]

Well, it was a great day to go out and show the car @ a local EuroSunday event here in Sacramento Ca. Got on the road with another DMC and started down the road. About 2 miles into the drive the car just quit. Still had all electrical powerl, just seamed like no gas. Got pulled to the side of the Freeway. The car turnes over well, it seemes like its not getting any fuel. I got it towed back home so I could take a look at the fuel pump. I opened it up and found the top of the pump boot that covers it had alot of cracks and tears in it. So the top of the pump was just covered in corosion. Also when I turn the key to fist position I dont hear the pump priming now

So how do I check to see if the pump is bad? I took the pump out and cleaned the conections. Could it be the RPM relay? I had the whole system cleaned out by DMCGG about 9 years and have been very good about keeping fresh gas in it. This car only has 18000 on it. 9000 since the fuel clean out.

HELP......:hmm:

[DMC5180]

Check fuse 7 first and make sure it's OK. If you don't have a fuse 7 in the box, check for a stand alone Inline fuse holder. If OK, Jumper the the fuel pump circuit (white/purple & Brown wires) at the rpm relay plug. The pump either runs or it doesn't. If not, check for 12V power at fuel pump electrical connector. If you have it there, your pump is dead.

[Soundkillr]

could very well be a bad rpm relay, get a second one if you can, and worst case, drive it again until it dies. Then plug in your replacement and see if it runs.

[Farrar]

Have you checked your inertia switch? If it's lost its connection to ground your pump won't run.

Farrar

[nofear365]

Have you checked your inertia switch? If it's lost its connection to ground your pump won't run.

Farrar

+1

I had the same problem and the inertia switch was my issue.

[DMC5180]

Have you checked your inertia switch? If it's lost its connection to ground your pump won't run.

Farrar

Good Point! I always forget about that one.

[dmc3130]

Thanks for the input. I will check these items and get back to you all. Its a good thing that all this happened anyway. The boot for the pump seems to be really soft and the cover for the pump was totally cracked and letting alot of water in on the pump. All conections were in bad shape. How do I get the pump cover off hoses?? With out cutting them off the fittings of the pump. They are harder type of fuel line.:wrenchin:

[David T]

The fuel pump electrical circuit has quite a few weak points. Here is a list of the more common ones:
Fuse #7, the wires and connectors in the fuse-block
The connector plug in the wiring harness up by the washer bottle
The connections right on the pump (they get all rotten when the boot fills up with water)
The inertia switch. Make sure it has a white splotch of paint on it and is mounted on the left wall of the footwell, not the Lambda counter.
The RPM relay. They seem to have a medium-to-high failure rate.
Some of the most creative wiring is demonstrated by DPO's (Dreaded Previous Owners) in the fuel pump circuit to bypass all of the safety devices and get the pump running. If the fuel pump stops the motor stops almost immediately so it is VERY important to have a reliable electrical circuit for the fuel pump. Bypassing is OK for troubleshooting and to limp home, not as a permanent repair.
David Teitelbaum

[dmc3130]

Thanks for the list. The PO was my Dad who you would want as a PO on this car. Very detailed and orginized. Never took shortcuts.... SOOOO I'm hoping for a simpler fix...I'll keep you all posted.
:shyshy:

[dmc3130]

OK, here is where I'm at

Checked fuse #7 Good
Checked Inertia Switch plunger is down.
Made jumper to #30 and #87
Pluged the cleaned up pump back in and installed jumper, it made a spark and I can hear the pump trying to go but not running ( should make some kind of noise, right ?)
So does that mean the pump is bad? That's were I'm headed. Stop me if I'm wrong and order something I don't need. Also do I need a new inertia switch. Mine is stamped
06. 3. 81 But looks brand new. Lastly, how do I get the top cover of the pump off without cutting the connectors off for the fuel lines??

[Bitsyncmaster]

If you have a multimeter, jumper the RPM relay and read the voltage right on the two terminals of the pump. Yes the pump should be making noise when running but if the voltage is to low the pump will stall. My pump will keep running down to about 8 volts but you should expect to to see 10 to 11 volts without the engine running.

[dmc3130]

Just checked with meter, I have 7.92 @ the pump. What should I do to get it up to 10-11 Volts?

[Bitsyncmaster]

Just checked with meter, I have 7.92 @ the pump. What should I do to get it up to 10-11 Volts?

What I do to find where the problems are:

Measure the voltage to ground at the fuse. Most fuses have a little metal exposed at the top of the fuse. Record that reading.

Measure the voltage to ground of the + side of the pump. Record that reading.

Measure the voltage to ground of the - side of the pump. Record that reading.

The cars wiring and connectors drop quite a lot of voltage when the pump is drawing 7 or 8 amps. But your looking to see where bad connections exist. On mine it was the connector right near the pump (0.5 volts) and at the fuse (0.5 volts). I then improved it another 0.4 volts by making a new ground on the inertia switch.

I recommend you remove that two pin connector at the pump and just splice the wires. You really don't need that connector. It's just one more thing that can fail someday.

[dmc3130]

What I do to find where the problems are:

Measure the voltage to ground at the fuse. Most fuses have a little metal exposed at the top of the fuse. Record that reading.

Measure the voltage to ground of the + side of the pump. Record that reading.

Measure the voltage to ground of the - side of the pump. Record that reading.

The cars wiring and connectors drop quite a lot of voltage when the pump is drawing 7 or 8 amps. But your looking to see where bad connections exist. On mine it was the connector right near the pump (0.5 volts) and at the fuse (0.5 volts). I then improved it another 0.4 volts by making a new ground on the inertia switch.

I recommend you remove that two pin connector at the pump and just splice the wires. You really don't need that connector. It's just one more thing that can fail someday.

I checked the fuse voltage and got 12.26
Then the voltage to the pump wires with the pump disconnected and got 12.25
I ran a main lead and ground to the pump by itself and got nothing from the pump. I'm thinking I just have a bad pump. I just want to go thru everything before I order the parts. Should I get a RPM relay as well since mine lookd to be original??

[Bitsyncmaster]

I checked the fuse voltage and got 12.26
Then the voltage to the pump wires with the pump disconnected and got 12.25
I ran a main lead and ground to the pump by itself and got nothing from the pump. I'm thinking I just have a bad pump. I just want to go thru everything before I order the parts. Should I get a RPM relay as well since mine lookd to be original??

For finding bad connections you have to measure the voltages with the load (pump installed and RPM relay jumpered). If your pump is frozen it may not be a good idea to do that test because the wires may overheat.

The RPM relays fail mostly because of broken solder joints on the PCB. That is caused by the many heat and cool cycles the RPM relays see with use. The older they are the more cycles they have seen.

[dmc3130]

Just an update. Installed the new pump system from SpecialT on Saturday. All went well. The instructions that came with the pump kit was nice. No leaks and runs like a champ. Thanks for all the help from all you DMCtalkers. :thumbup2:

[jawn101]

Really glad to hear it Stephen! I was worried that gorgeous car of yours might be immobile :)

Can't wait to get together again, and would love to see one of Hervey's pumps in person!

[dmc3130]

The pump it's self looks the same, I didn't get the high output one. But the rest of the setup is different. Much simpler design with less room for this to go wrong. If we get a nice weekend this winter of the next Eurosunday I'll let you know.:approve:

[jawn101]

Look forward to it! I still hope to get everyone together for a few beers and adjusting 2100s torsion bars :)