Fuel pump woes

V

V8P6B

Member
Hi All, Noticed lately that my car was getting very difficult to start after being left for a few days, the battery would almost go flat winding it over before it started to fire.No such probs if its only left a short time.

So... I got a fuel pump rebuild kit from Geoff at Wins, along with a new set of fuel pipes that go either side of the filter. Jacked up the front of the car to remove the pump, stripped it down carefully, and installed all the new parts from the service kit. Quite a fiddly job trying to get the pump diaphragm hooked up to the arm. Even trickier trying to swap out the little valves. Anyway, eventually got it all back together, refitted it to the car, and tried to start it. The fuel pump won't pump any fuel now... :cry: I've removed it and refitted it a couple of times, cos I worried about the actuator arm not engaging on the drive cam properly, all to no avail. I just can't get it to pump any fuel up. I checked the positioning of the valves to make sure I hadn't put them in backwards, but all looks ok. What next? Any ideas? I thought I'd checked all the obvious things.. :cry:
 
It is possible, but not very easy, to put the lever the wrong side of the cam, but if you do manage it tends to break the pump. Personally I'd remove it again, borrow the outlet pipe and screw it into the inlet, immerse that in petrol, and manually operate the pump and see what happens.
 
harveyp6 said:
It is possible, but not very easy, to put the lever the wrong side of the cam, but if you do manage it tends to break the pump. Personally I'd remove it again, borrow the outlet pipe and screw it into the inlet, immerse that in petrol, and manually operate the pump and see what happens.
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That is such a good idea! I'll have a go at that tomorrow.. Had a belly full of it today, one way & another, and I've just got clean.. :) :roll:
 
How did you stop the petrol escaping when you took the pump off ? It will take ages to pump up if the fuel lines are full of air
 
Providing you have at least 5 gallons in the tank the weight of it will force it up to the pump. Less than that and they do have problems pulling it up if you run right out, but that's easily solved by jacking up the back of the car, in the same way as you jack up the front to stop the petrol pouring out of the pipe when you remove the pump.
 
The tank's just under 1/4 full, heading towards the reserve. Fuel did start dripping when I loosened the union, but I jacked the front of the car up, and once it was on axle stands, no more fuel came out. I did forget to jack the car up when I removed the pump a second time, and fuel did start dripping again, so basically when the car's on the level, fuel gets to the pump inlet on its own. I'm pretty sure the problem is with the refurbed pump, maybe I did something wrong rebuilding it, so I'll check that tomorrow. I did almost kill the battery (good job its a good battery) cranking it to see if any fuel was coming out from the top of the filter, but unfortunately none did. The annoying thing was, it did work before, but it seemed to allow the fuel back through it over a week, so it was getting tricky to start it if it was left for more than a couple of days.
 
I have exactly the same problem with my p6B, left for more than a week it takes a lot of cranking to get it to start, I have been blaming the mechanical pump same as you, will be interesting to see if your rebuid provides a cure. Luckily I have been using the p6B every day as my main work car is in need a of a new cltuch.

Graeme
 
V8P6B said:
The tank's just under 1/4 full, heading towards the reserve. Fuel did start dripping when I loosened the union, but I jacked the front of the car up, and once it was on axle stands, no more fuel came out.
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Jack the back up and crack the pipes to make sure fuel is at the pump when you try again.
 
unstable load said:
V8P6B said:
The tank's just under 1/4 full, heading towards the reserve. Fuel did start dripping when I loosened the union, but I jacked the front of the car up, and once it was on axle stands, no more fuel came out.
Click to expand...
Jack the back up and crack the pipes to make sure fuel is at the pump when you try again.
Click to expand...

I thought before I started anything on the car today, I'd just try jacking the back up, and try to start the engine. With the back jacked up, I wound it over for about 30secs and then it fired up! Result! Didn't have to take the pump off again. Been for a drive, seems ok, no leaks, no issues. Seems to run a bit better with a nice clean fuel filter and a pump that's pumping properly too. Someone who previously owned it had chopped the fuel lines about to put a cheaper fuel filter in some indeterminate time ago, but now I've got the proper setup with the proper filter. All I need now is the bracket to hold the fuel filter in place. Anyone got one? Did think about using a cable tie, but don't like the idea of clamping something made of plastic with fuel going through it to something that gets hot, like the front of the engine where the bracket used to be :shock: If I can't get one, I'll just make one.

Anyway, thanks for the advice! Little tips from guys with experience is absolutely brilliant. Cheers again guys!
 
I've got one, but it's for the engine breather filter, not the fuel filter, and they're different even though they use the same filter.
 
Ok, no worries.. It's just occurred to me that there a big box of spare engine parts in my shed that I haven't even looked at yet... Maybe I'll get lucky... :)
 
Well, went for a lovely drive in the sunshine today, what a scorcher! 8) Parked up outside a lovely country pub for a spot of liquid ( non alcoholic) refreshment, what could be better. Went to leave, started the car up ok, then 20 yards down the road it packed up, started losing power, then stopped. IT had been sitting in direct sunlight, so I thought it might be fuel vapourisation, the symptoms pointed to it, the fuel filter was empty. Pump had been working beautifully since I rebuilt it last week, (once I'd got it going), and I've done about 80 miles since then, with no problems. After it broke down today, I thought, no worries, we're sitting outside a lovely country pub, I'll let it cool down and then try again. Left it for about 40 minutes while we had another (non alcoholic) drink, but still no joy. By this time, the pub had shut, so I called the breakdown services. Sat waiting in the scorching sun for nearly 2 hours, by which time the sun had gone down. I had been periodically trying to start it, even tried the jacking up the back trick, no joy. Anyway, eventually the recovery guy phoned to say he was 1/2 a mile away, so I thought I'd try & start it again, just to make sure it was still knackered, and it fired straight up... :roll: It was running beautifully again when the recovery truck turned up. The funny thing was, the recovery truck was boiling its brains out when it got to me, steam pouring out of it. The guy apologised for taking so long, but his lorry had decided to blow a head gasket. Still, the driver was really chuffed that he'd got to his last job of the day, didn't have to worry about getting me home, and as he said, his lorry's not going anywhere, he's off duty, and he's stranded outside a lovely country pub that had just opened for the evening session.. So win win all round.. :wink:
 
I know this is going to sound silly on a fuel thread - but you haven't got an ignition issue as well have you? Something silly like a duff capacitor (if still on points).

Otherwise, it sounds to me like there is something peculiar going on in float chamber land, perhaps a sticky needle valve that allows the carb to flood one minute and starve the next?

Chris
 
In the same vein Chris, how about an electrical supply problem, like an ignition switch problem, as it only seems to happen when starting, rather than cutting out when running.

Back to the fuel side of things, how about crud in the tank completely blocking the fuel line ? You may get flow with just an open pipe, but maybe when the pump starts to pull fluid through it pulls the crud up too.
 
Would it start on the reserve supply ? If so it could be the nylon flap thingy blocking the main supply pickup
I'd give the fuel line a good blast with an airline from the pump back to the tank
 
chrisyork said:
I know this is going to sound silly on a fuel thread - but you haven't got an ignition issue as well have you? Something silly like a duff capacitor (if still on points).

Otherwise, it sounds to me like there is something peculiar going on in float chamber land, perhaps a sticky needle valve that allows the carb to flood one minute and starve the next?

Chris
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I'm running pertronix ignitor II, with flamethrower II coil, and did check spark (it was mahoosive!)

When I had the problem, the fuel filter was pretty much empty, no fuel getting to it. Did try to start on the reserve, no joy. I did notice that when I accepted the offer of a try at a jump start, I had a job to get the battery cover lid off, as the lid had melted to the earth lead from the battery. Normally, when I start the car, it starts reasonably ok, but have noticed that the starter has been a bit lazy lately, so I think with the extensive cranking, the earth strap (which was a bit frayed where it bolts to the boot floor) was a bit lossy, and getting hot. This really only happens when the car is being extensively cranked to try and start it. I've now fitted a brand new earth cable to the battery, and the starter now spins much, much faster, which can't be bad for both the electrics and the fuel pump.

There's been no evidence of any problems with float chambers, no evidence of any fuel coming out of the overflows etc, and when running, it runs beautifully, and was doing so immediately before being switched off, and returns reasonable economy for a V8 (about 20mpg). I think the big tell was the empty fuel filter; it was very hot under the bonnet too, and when the problem first happened, it did fire up, but then spluttered and died like it was running out of fuel, but then any further attempts to start it failed. Once it had cooled right down, after 2 hours, it fired up after cranking for a short time which was weird, and slightly embarassing with the imminent arrival of the breakdown truck. :roll:

I did wonder whether there was an intermittent problem with my newly refurbed fuel pump, like a sticky valve in it or something; there was definitely no fuel being pumped, and I did try and start it many times during my 2 hour wait. I do have to say how impressed I am with my optima red top battery, it never went completely flat even after all that cranking. I am wondering if the problem was caused by a combination of a dodgy earth lead causing slow cranking, coupled with some element of fuel vaporisation, which couldn't be overcome with the slow cranking. I don't know. What I do know is that the car starts much more easily since changing the earth lead.

So, I think its worth seeing what happens . I am definitely thinking of fitting an electric cooling fan, and am now thinking of fitting an electric fuel pump too. I don't necessarily want a full time electric pump, but something I can switch on if I get a problem, but am not too sure about the logistics of it at the moment.
 
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