noise from fuel pump
Discussion
Hi Nads. Same thing happened to mine a couple of yrs back. Not good news......the car started spluttering and occasionally stalled although the pump was still working (noisily). A replacement pump made no difference and it turned out to be corrosion in the swirl pot which was restricting fuel flow. Had to have a new one made up, but the problem didn't go away. Twice after that the fuel pump died suddenly without warning; it seemed that debris was getting from the fuel tanks into the system (despite having had the tanks cleaned and re-sealed just months before). The latest cure is to have an additional fuel filter placed before the pump right at the back of the car. Has worked ok for a few months, fingers crossed!
Mine has been very nosiy in the 14 years or so ive had the car. Fitted a new one and it was quieter for a while but has got noisier over time. The pump was easily availble from a Bosch dealer and was reasonably priced but make sure you get the number off the old pump. There are a number of variants and not all will fit properly. I aslo experienced the motor stopping for no apparent reason not long after changing the pump but it hasnt recurred. I put it down to crap in the fuel pipes but havent invetigated further.
The 2.8i Pump is just very noisy, I have three spares, and they are all noisy. Presumably due to having to work at 7 Bar at a decent fuel flow rate. The v8 pump is much less noisy, as it is relatively unstressed, only running at 2.5 Bar.
Mounting the 280i pump on rubber bobbins cut down the noise transmitted to the inside of the car considerably.
-Jim
Mounting the 280i pump on rubber bobbins cut down the noise transmitted to the inside of the car considerably.
-Jim
Thanks for the advice.
The reason why I posted was because it has become more noisy recently. In fact the high pitched buzz can be heard with the near side window open even while the exhausts are happily entertaining passers by. I don't think I ever noticed the pump noise before.
Cheers
Nads
The reason why I posted was because it has become more noisy recently. In fact the high pitched buzz can be heard with the near side window open even while the exhausts are happily entertaining passers by. I don't think I ever noticed the pump noise before.
Cheers
Nads
My fuel pump also switches on with the ignition. I've got the (apparently) correct relay to sort it, but am scratching my head trying to work out what's stopping it working.
It's suppose to work only when the engine runs, so that in event of an accident and the fuel lines break, fuel doesn't spray everywhere.
Later Fords had an inertia switch which apparently had a similar effect.
It's suppose to work only when the engine runs, so that in event of an accident and the fuel lines break, fuel doesn't spray everywhere.
Later Fords had an inertia switch which apparently had a similar effect.
On the 280 there is a green plug on the side of the fuel metering unit. When the internal contact is broken, the fuel pump will be powered via a relay (with the ignition on of course) . The problem is the contacts inside the Metering unit get dirty very quickly, and stop the pump running. Also, it's not that safe as if you hold the metering unit upside down ( simulating an exciting off road event) , the fuel pump activates too! so I don't see it as a great safety feature really.
-Jim
-Jim
Alisdair (Hargo)'s car had the permanently-running pump too. One possible cause of this is that someone has been tampering with the airflow meter and the spring tension is too weak. The flap should return until it opens a contact and shuts off the pump relay. Too little spring tension and the contact won't open.
If you unplug the AFM the relay should drop out and stop the pump. In Al's case it wasn't, so we traced the electrics and eventually found a wire link that had been soldered across the tracks of the PCB inside the red 'steering module'.
Now it looked as though it had been done at the factory, whether intentionally or otherwise I don't know, but maybe Lucas changed something (maybe the idea was that an ignition-switched pump gets the rail up to pressure before you crank, I dunno).
We snipped the link and 'normal' service was restored, ie the pump doesn't run until you crank.
As Jchase says, on the 280 the meter flap does the same thing... but with respect I think his description is wrong, since if the contacts were duff it would NOT cause the pump to run....
A duff relay however could give an intermittent pump. What can happen is that the current drain causes the plastics of the relay to soften, allowing the moving parts to shift and fail to contact. Alternatively arced contacts would do it - pumps are 'inductive' loads and the high initial current drain causes sparks that erode (arc) the contacts.
As for Combine's car, it could be that like Hargo he has a link where the diagrams suggest there shouldn't be one. I'd suggest pulling the red 'relay' out and seeing whether the pump still runs with the ignition on...
For any interested parties, I could try to post a picture of the soldered link?
If you unplug the AFM the relay should drop out and stop the pump. In Al's case it wasn't, so we traced the electrics and eventually found a wire link that had been soldered across the tracks of the PCB inside the red 'steering module'.
Now it looked as though it had been done at the factory, whether intentionally or otherwise I don't know, but maybe Lucas changed something (maybe the idea was that an ignition-switched pump gets the rail up to pressure before you crank, I dunno).
We snipped the link and 'normal' service was restored, ie the pump doesn't run until you crank.
As Jchase says, on the 280 the meter flap does the same thing... but with respect I think his description is wrong, since if the contacts were duff it would NOT cause the pump to run....
A duff relay however could give an intermittent pump. What can happen is that the current drain causes the plastics of the relay to soften, allowing the moving parts to shift and fail to contact. Alternatively arced contacts would do it - pumps are 'inductive' loads and the high initial current drain causes sparks that erode (arc) the contacts. As for Combine's car, it could be that like Hargo he has a link where the diagrams suggest there shouldn't be one. I'd suggest pulling the red 'relay' out and seeing whether the pump still runs with the ignition on...
For any interested parties, I could try to post a picture of the soldered link?
adam quantrill said:
I find mine gets a little noisy in hot weather or with a low fuel level, but shuts up when it gets cooler.
Same symptoms on mine.
Just noticed the pump noise lately as well with hot weather. Thought that the pump was on its way out, but perhaps I am lucky and will check during a cool run. Thanks for the 'tip' Adam. Still considering to get a replacement as 170.000km and 18 years is a lot for the pump.
Rob
Hi Wedg1e,
Maybe not all fuel metering units are the same, but of the four I've played with, two had the switch inside. The contacts are underneath the metering plate, which seems to get oil contamination on it, making the contact intermittent. The circuit for the switch is broken to run the pump, as per the red Ford Capri 2.8i supplement. I thought the Red steering relay was on the 350? I dunno, it is late...
By the way if you want a 2.8i pump, let me know, I've got two or three in the shed.
-jim
Maybe not all fuel metering units are the same, but of the four I've played with, two had the switch inside. The contacts are underneath the metering plate, which seems to get oil contamination on it, making the contact intermittent. The circuit for the switch is broken to run the pump, as per the red Ford Capri 2.8i supplement. I thought the Red steering relay was on the 350? I dunno, it is late...
By the way if you want a 2.8i pump, let me know, I've got two or three in the shed.
-jim
jchase said:
Hi Wedg1e,
Maybe not all fuel metering units are the same, but of the four I've played with, two had the switch inside. The contacts are underneath the metering plate, which seems to get oil contamination on it, making the contact intermittent. The circuit for the switch is broken to run the pump, as per the red Ford Capri 2.8i supplement. I thought the Red steering relay was on the 350? I dunno, it is late...
By the way if you want a 2.8i pump, let me know, I've got two or three in the shed.
-jim
Exactly, Jim, so I don't see how grotty contacts will make the pump FAIL. If the contacts didn't close, the pump would run, surely....?
Yes, the steering relay is on the V8; I was talking about both systems without distinguishing them very well, sorry.
Indeed it is late, but what happened with my 280i was no fuel pump under cranking, but fuel pump run when the connector removed . Shouldn't happen I though to myself - so with ignition on, I took the air filter out, and stuck my hand in there to unseat the metering plate, which was stuck down. I pushed it a bit harder and got a nice nip of current from the relay back emf. Car then started fine and was okay for a week or so. This happened again, after a week standing, but I used a stick that time!
Eventually I cleaned the contacts up and the disc of all the oil crud, and it didn't do it again. I guess it could have been oil goop down the side of the plate, and not the goop on the contacts, as I cleaned them at the same time, but when on the bench it did look like the contacts were sticking together.
-Jim
Eventually I cleaned the contacts up and the disc of all the oil crud, and it didn't do it again. I guess it could have been oil goop down the side of the plate, and not the goop on the contacts, as I cleaned them at the same time, but when on the bench it did look like the contacts were sticking together.
-Jim
niva441 said:
Later Fords had an inertia switch which apparently had a similar effect.
Yes - these are great fun. There is a switch in the spare tyre well so that when you get a puncture, change the wheel and throw the old one in the back...
the car won't start.
Gives hours of fun to anyone not aware. Those Ford bods had a good sense of humour.
Actually, I am sure it is usefull should you get a knock in the back.
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