Fuel pump issue

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texcarguy

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Tonight I made a short run around the neighborhood in my CS prior to our planned early morning departure for Vintage at the Vinyard tomorrow morning.. Alas, about 4 blocks from home, the engine lost power, and sputtered to a halt. I could tell immediately the problem, because I couldn't hear the fuel pump ticking away.... Just prior to this drive, I had left the ignition on, fuel pump running for about 10-15 minutes (with engine off), to check for a suspected leaky float needle valve on one of the Webers.

This exact scenario happened once before, several weeks ago, with similar precursor... I had run the pump without engine running for a pretty good time...After tinkering around the car, checking power to the pump, etc, I re-energized the system, and behold, the pump started working again.

Same thing tonight... I just sat, waited about 5 minutes... turned on the ignition.. ahhh, there's that ticking sound I love to hear.

Now I'm a bit leary about blasting off tomorrow (but not enough to alter plans)... My supposition is that perhaps the pump, running continuously against a blank wall at the carbs, doesn't get the benefit of new, cooler fuel going through, overheats, and then takes a break.. in which case, if I avoid leaving the pump running without engine I should be okay.

Or... this may just be a harbinger of final fuel pump failure in the not-too-distant future (say, somewhere between Memphis and Nashville on the way to Winston-Salem).

Anyone else had a similar experience, or knowledge of this pump to shed some light on my issue?
 
vapor lock?

That's a reasonable thought, but I feel it's unlikely in this case. First, that shouldn't stop the pump from ticking... next, it was a near cold engine, hadn't been run all day, and this was early evening and a less-than-2-minute drive when it quit on me.

My guess is the pump was NOT working when I started up, and I just got that 3-4 blocks on the fuel in the bowls (triple webers). Thanks for your response!
 
What kind of pump is it?
I ask because on injected E9s the pump is a "roller" type so it tends to "humm" rather than "tick".
If it's a modern after market pump (Facet etc) it may have thermal overload protection which makes it cut off. The maker should be able to tell you.
Is there a relay in the pump electrical circuit? It could be "bad" or failing
I am assuming it's not an SU pump (MG's etc) which used to have to be thumped occasionally due to sticky points :p
Malc
 
I had a similar problem 2 years ago. ( Electrical fuel pump) I decided to open up the fuel pump to understand how it worked. I discovered a small tear in the rubber diaphragm. I replaced the pump and been problem free since.
 
fuel pump no workee!

I apologize if I seem to be hijacking your thread however I also had a suspected fuel pump problem TODAY!.
This is a long post but...
Maybe there is some common diagnosis.

Background:
My car was originally a carby 2800 and somewhere in its life it has been converted and rebadged as a 3.0 CSi. The engine is not a D-jet as originally fitted but a later model( L-jet?) with air flow meter.
I say this because it makes using wiring diagrams etc fairly difficult in this hybrid environment. Anyway the engine ,ECU.Wiring loom and fuel pump are all typically EFI. and were all part of the transplant.

As Malc says... the EFI pump is a roller type... hanging underfloor and above the rear R/hand drive shaft.

The Symptoms:
Engine would die after 10 minutes running and go again on restarting. Today it went down to a few secondsbefore dying.
I suspect the pump but have not finished the diagnosis.
The weather is cool and unlike your carbies the EFI system runs at higher pressures largely precluding Vapourlock?

Make sure you check these items:
Fuel:
Any strainer in the actual pump inlet port?..clean it.
In-tank pick-up tube. Is it clear? reverse blow back into tank.
In-line fuel filter/canister..replace or check there is a clear flow ie. can you blow through it? (removed and dry)
With a cool engine (fire risk) remove a supply hose under the bonnet. Does the pump supply fuel into a container?
If you have a fuel pressure gauge/tester..tap into the fuel system and check pump pressure.
If your carby system has a return flow system like the EFI..check that it is working as the return fuel also cools the electric pump ( no oxygen present ..so no explosion risk).
Electrics:
Is there a relay controlling the pump? check/replace. I am about to hot-wire the pump direct from the battery with a long wire to bypass the relay.
If the car then runs OK I will take a closer look at the relay.
Pump wiring. clean/spray the contacts terminals as they are exposed to dirt etc under the car. Also check the earth contact lead to the body or loom.

Hope this helps.

Now a couple of hijack questions for me.
Does anyone know which relay controls the pump? ....part #?......what does the pin-out look like? so that I can identify it.

What is the normal operating pressure ( at the fuel rail) for an EFI system?

Thanks and good luck

Bob
 
Bob
Re your hijack

Fuel pump relay is usually situated near the ECU. However if your car has been "modified" it could be anywhere!
It is usually a bog standard 4 pin/blade type. Assignments are 31b, 31, 15, 87

Pressure 2bar (~28psi) is a good place to start
HTH
Malc
 
Thanks Malc. I will have a look.

Andre also makes a good point about diaphrams.

You haven't indicated what type of pump is on your carby engine..and I don't have enough E9 experience to guess accurately.

Mechanical pumps:..(ie those mounted on the side of the engine block and operated by a pushrod) are usually the diaphram type.
Some Electric pumps also use diaphrams.
Diaphrams usually apply to low pressure systems ie. where the fuel is pumped into the carby float bowl and supply is shut off by a needle and seat assembly. The bowl refills as the fuel is used.
(A high pressure "roller" EFI pump would blow this system apart!)

Perished rubber, or even a pinhole in the diaphram can cause lack of pump pressure and fuel starvation. Some pumps are repairable with a kit. A repairable pump would have a ring of bolts or something allowing separation of top and bottom section to fit new diaphram between...otherwise it is a replacement.

I reckon...beg borrow or steal a spare pump ..regardless of type..and replace to eliminate/isolate the problem.
A spare pump is always a good investment to have in the workshop/garage.
(says he, who doesn't have one, but is now about to buy new pump!)

Again, hope this helps

Cheers
Bob
 
texcarguy said:
Tonight I made a short run around the neighborhood in my CS prior to our planned early morning departure for Vintage at the Vinyard tomorrow morning.. Alas, about 4 blocks from home, the engine lost power, and sputtered to a halt. I could tell immediately the problem, because I couldn't hear the fuel pump ticking away.... Just prior to this drive, I had left the ignition on, fuel pump running for about 10-15 minutes (with engine off), to check for a suspected leaky float needle valve on one of the Webers.

This exact scenario happened once before, several weeks ago, with similar precursor... I had run the pump without engine running for a pretty good time...After tinkering around the car, checking power to the pump, etc, I re-energized the system, and behold, the pump started working again.

Same thing tonight... I just sat, waited about 5 minutes... turned on the ignition.. ahhh, there's that ticking sound I love to hear.

Now I'm a bit leary about blasting off tomorrow (but not enough to alter plans)... My supposition is that perhaps the pump, running continuously against a blank wall at the carbs, doesn't get the benefit of new, cooler fuel going through, overheats, and then takes a break.. in which case, if I avoid leaving the pump running without engine I should be okay.

Or... this may just be a harbinger of final fuel pump failure in the not-too-distant future (say, somewhere between Memphis and Nashville on the way to Winston-Salem).

Anyone else had a similar experience, or knowledge of this pump to shed some light on my issue?
Click to expand...

If you have one of the little solid state pumps, like Facet, maybe it is overheating and shutting off. Probably the best thing to do is to see if you can buy another one, like at a local auto parts store to bring along as insurance. As I recall, they don't cost much. Check to see if the electrical connections are the same as what you now have and it won't be difficult to replace if you have to do a roadside swap. I had to do that once.... (car started to cut out when accelerating).
 
If you have one of the little solid state pumps, like Facet, maybe it is overheating and shutting off. Probably the best thing to do is to see if you can buy another one, like at a local auto parts store to bring along as insurance. As I recall, they don't cost much. Check to see if the electrical connections are the same as what you now have and it won't be difficult to replace if you have to do a roadside swap. I had to do that once.... (car started to cut out when accelerating).
Click to expand...

Thanks Bill... that was my basic plan, albeit never quite yet got around to buying the spare... I figure there's always a CarQuest auto parts store within reasonable range.

We've just completed one half of our 2700 mile round trip odyssey to Vintage at the Vinyards, and so far the little coupe has been good to us![/quote]
 
Fuel pump finale

Well, my fuel pump issue finally resolved itself... after having driven some 2300 miles of our roundtrip V@V journey, and pulling into our little hotel in New Orleans, the old baby sputtered and gave up the ghost... We literally were able to just turn off the street and halfway into the covered parking!

I used the starter and first gear to "winch" the E9 into a parking stall, and next morning, with help from a local mobile repair guy, slapped a generic unit from Autozone on the car and breezed on into Austin without further incident.

Thanks for all the helpful comments. Next time I'll take everyone's advance and keep a spare on hand.
 
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