Defender 90 TD5 Fuel Whine - HELP PLEASE

Hi

Just need your thoughts on this one:

Had fuel filter changed on my TD5 Defender, as light came up on dash "water in fuel". Immediately that the fuel filter was put on, and was primed, there was an audiable whine, for perhaps 30 secs, then a click from dash, and the whine was gone. There is no discernable whine noise when driving. I can turn ignition on and off and whine is back, until click is heard. I did notice somewhere that as this a non-original Landrover fuel filter is used, this might be a problem - or is it that the fuel pump is knackered, and I need a new one fitting? Just a total baffler, as prior to removing old fuel filter there was no whine at all? HELP PLEASE. Thanks. Rob

If you turn on the ignition the pump will run. If you do not start the engine the pump will switch off after about 30 secs. Actually the ECU switches it off. The click is the fuel pump relay. Try this though, put foot flat on accelerator and switch on ignition and start the engine. This puts the ECU into 'bleed' mode and is handy after changing a filter. For the rest, you could check that the filter is tight as it is possible that it is letting air in. The only way to check that is to put some transparent pipe in the line, and for that you need the fittings.

Jim

Thanks for the information. I did try what you suggested and there is still the whine. Have tightened up as much as I can the filter. Looks like it might have to go to the garage to see if they can determine if there is an air leak - but have a feeling they might say - you need a replacement pump mate Rob

One of our drillers has this on his 110. its coming from the back though. its been like it for over 12months and everytime i see him i ask if hes getting it changed, but it just keeps working anyway!

G

Griff

Cheers man - perhaps I will leave it a little while and see if dies (sods law it will when I am setting out at 4am), or it rectifies itself. The sound is like a fly - perhaps a fly swat right against the filter will sort it - damn whine!!! Thanks for your post. Rob

I had some right problems with my TD5 90 not long after I bought it... There was a whine from the rear end and I figured it was the fuel pump as it got louder if I took the filler cap off. It got to the stage where it would cut out every 5 miles or so and I had to turn the engine off for 5 minutes and it'd be fine (for the next few miles).

Anyways, it went back to Simmonite's under warranty and they put a new genuine LR fuel pump on (so they tell me). Anyway, the noise went away for at least a few hours! So it went back, accompanied by a bollocking for not fixing it. After a fair bit of fettling in the workshop they replaced the airflow meter and so far (a month or so on) it's as quiet as a whistle... So give that a whirl - it turns out on mine it might not have been the fuel pump after all as it didn't go away after it was changed.

Turns our the fuel pump was trying to suck too much fuel up and eventually flooding the engine. Guess that's what we get with ECUs and things - the slightest thing confuses them and they start misbehaving and telling things to do odd stuff! Hope this helps!

Steve

Thanks. Will check out the airflow meter angle - am presuming that this will be cheaper to sort that the fuel pump. I wish now that I had put back on the old fuel filter just to see if the whine went away - anyway thanks for your post. BTW - nice truck Rob

AFAIK the air flow meter and the fuel pump have no connection, electrical or electronic. The ECU doesn't even know what the fuel pump pressure is. So changing the AFM will not and can not stop a whine in the fuel pump.

JimAttrill said:

AFAIK the air flow meter and the fuel pump have no connection, electrical or electronic. The ECU doesn't even know what the fuel pump pressure is. So changing the AFM will not and can not stop a whine in the fuel pump.

Click to expand...

It did on mine for some reason! I'm no expert, but I would guess that if the ECU doesn't know how much air is getting in, it won't know how much fuel to bring into the engine. That's why mine was flooding the engine, cos it was over-fueling it as it thought more air was getting in than there actually was.

The fuelling to the engine is governed by the pump and the regulator, neither of which are electronic or coupled to the ECU. If the Air Flow Meter fails or is disconnected, the system goes to a default setting which will under-fuel rather than the opposite. So if your AFM fails, your engine will go slowly. It will not flood the engine.

If your fuel pump whines and makes strange noises, it will be air in the system, or the pump being fud. If that is fixed, the pump will be quieter. But most pump whines are caused by the pump itself being fud. The AFM has absolutely nothing to do with the fuel pump.

Hi All

Thanks again for all the posts. The whine seems to have quietened down, to a low "wasp" type of noise. Have been told, by a garage that it is the pump, and could last 3 days or 3 years. I think will just run it and play it by ear. Lets hope it will rain for a muddy weekend!!!

Having read my own posts, I reckon I am being too pedantic. With a TD5, whatever fixes your problem is the answer. Sometimes running round the vehicle while reciting the Lord's prayer backwards can help

I here you Jim Having just gone thru the whole fuel pump saga myself, the only tip I can give you is that if it stops making a noise.... well lets just say that even a 90 is f...ing heavy to push.