ITP would this be a check it's working

[blacknwhite]

I changed my ITP last week (and UPB today). I have driven about knowing the ITP was duff from the day I bought the car exactly a year ago. I have always driven with at least 1/4 tank, but now that the ITP has finally been changed, presumably I can now run it down to near empty (should I want).

The ITP is very quiet and if I open the filler cap I can just hear it. My head tells me just because I can hear it, it doesn't mean it's working. I wondered if I disconnected the UBP electrically and removed the tube from the UBP into the filter (and put the end into a bottle obviously), would the ITP on its own pump through to this point i.e. would I have flow?

I'd feel must better if I could prove it's actually pumping.

[mikesmith2]

I think the itp only moves fuel from one side to the other, hence when the ubp fails you get a none starter.

May well be wrong though.

[FrenchMike]

Originally Posted by blacknwhite

I changed my ITP last week (and UPB today). I have driven about knowing the ITP was duff from the day I bought the car exactly a year ago. I have always driven with at least 1/4 tank, but now that the ITP has finally been changed, presumably I can now run it down to near empty (should I want).

The ITP is very quiet and if I open the filler cap I can just hear it. My head tells me just because I can hear it, it doesn't mean it's working. I wondered if I disconnected the UBP electrically and removed the tube from the UBP into the filter (and put the end into a bottle obviously), would the ITP on its own pump through to this point i.e. would I have flow?

I'd feel must better if I could prove it's actually pumping.

Hi,

Don't worry,if you can hear it even just a lltle,it's enough,your pump works
correctly and so run your car with gauge under a quarter of tank

Happy motoring

Mike

[Union Wheels]

Originally Posted by blacknwhite

I changed my ITP last week (and UPB today). I have driven about knowing the ITP was duff from the day I bought the car exactly a year ago. I have always driven with at least 1/4 tank, but now that the ITP has finally been changed, presumably I can now run it down to near empty (should I want).

The ITP is very quiet and if I open the filler cap I can just hear it. My head tells me just because I can hear it, it doesn't mean it's working. I wondered if I disconnected the UBP electrically and removed the tube from the UBP into the filter (and put the end into a bottle obviously), would the ITP on its own pump through to this point i.e. would I have flow?

I'd feel must better if I could prove it's actually pumping.

Hi Bob
I have just changed the in tank pump on my car and if you do as you suggest, the in tank pump will pump diesel from the tank, through the under bonnet pump and into the bottle although the flow is not very rapid.

It seems that this would be an easy and conclusive test to carry out for the in tank pump.

Pete.

[Mike Noc]

Originally Posted by mikesmith2

I think the itp only moves fuel from one side to the other, hence when the ubp fails you get a none starter.

May well be wrong though.

Think it might do a bit more than that. The Freelander TD4 which also uses the M47R engine has an ITP but no saddle tank.

Mike

[crofts]

Originally Posted by Mike Noc

Think it might do a bit more than that. The Freelander TD4 which also uses the M47R engine has an ITP but no saddle tank. Mike

Mike. Your explanation would indicate there is an additional 'saddle tank' which is not correct, is It ?
T-cut posted up an excellent diagram of the fuel system. Bit of a clumsy design necessitated by the saddle tank though this was sorted with the later models with a one pump system (no under bonnet pump)
While I realise, with a new I/T pump, you can run the tank lower (& some members do...and get away with it), the consensus seems to be not to run the tank lower than 1/4. It could be the cheaper option than an earlier fail of the expensive, and fiddly to replace, ITP.
Of late I am beginning to see more & more examples of noisy U/B pumps with the eventual realisation that the ITP has been U/S for some time. We know, of course, that the U/B pump on it's own will run the car, usually providing there is at least a 1/4 tank. I note one member explained he has knowingly run his car, with just the U/B pump, for a year or so.
The additional 'load' on the U/B pump usually results in early failure of this pump though and I am quite surprised the U/B pump lasted a year.
Horses for courses as they say ! !

[Mike Noc]

Sorry if that sounds confusing. What I meant is that the Freelander tank is flat bottomed so if the ITP is only fitted to get fuel over the saddle in the CDT tank they wouldn't fit one in a Freelander. They do so it must do more than that.

I did 20k miles after my ITP pump packed up with no problems by keeping the tank over a quarter full, and the UBP pump was still going strong when I replaced them both.

Funnily enough I keep it as an emergency spare and it just did a couple of weeks in my daughter's Freelander after her pump went.

With the system working as it should you can safely run the tank down to low level before refilling with diesel. It really is a myth that it causes problems.

I've always done it and had one replacement ITP in 11 years and 313k miles of motoring, and when the pump was stripped down it was the commutator itself that had worn down, which is the way they seem to go.


Mike

[crofts]

I'm sure you are right Mike that it's a myth but I took the 1/4 tank story to heart when I bought my diesel tourer in 2003 and NEVER ran below a 1/4 tank.
Anyway, sods law, got caught short just once around 40,000 miles and went down to the low fuel light. Only did about 10 miles before filling up but had fears I may have knackered the ITP. Sure enough, listened, no noise. Garage confirmed ITP not working. So put 2 & 2 together & assumed I had caused the problem. Pump was replaced by Warranty Direct at Rover dealer (£407-ouch)
Only when I posted my experience did a member point out that the ITP had probably expired long before this event. Proves that if you keep the tank over a 1/4 continuously, the ITP can fail and you probably won't know until the U/B pump squeels with pain from overwork.