Mechanical Fuel Pump - MG Maestro 1600 R-Series

[matthewsemple]

I have an MG Maestro 1600 which hasn't been started for a couple of years and I am currently working through the issues on the iginition (spark, fuel, etc.)

These cars (R-Series) have a mechanical fuel pump located on the cam cover and mine seems to have failed (which I have read can happen if they are left unused). I bought a new-old-stock one on ebay and tried to fit that and there is an insulation block missing from the new one which I cannot get off the old one.

Before I spend a lot of time cutting this block off the old one, I thought I'd test the new one. According to the Haynes manual you can manually test them by fitting the inlet pipe and moving the little arm up and down and if the pump is working, fuel will come through. So I tested my old one, the new one and a third one I found in the garage. With all three of them, no fuel came through (there is some in the tank!)

So has anyone ever done this test or is this a myth? Do they only work when operated by the cam at much higher speed than I can wiggle the arm?

[Sussex Pete]

Probably worth repeating the test off the car with a smaller supply of fuel, like a jar or small can. That way you are taking out the remaining fuel lines from the test which may also have issues. You can also prove there would be suction by placing your finger over the end of the inlet pipe and operating the lever. You should feel the suction if it is working OK.

[Doctordiesel77]

as above and you might want to try blowing back through the feed pipe from the tank in case the gauze in the tank, or the pipe is blocked..a hole in the pipe would hinder things too

[matthewsemple]

Thanks, I'll try the test with the finger over the inlet as suggested. There is no problem with the fuel lines from the tank - a gentle suck and I had a mouthful of petrol (yuk!).

I was wondering whether I was doing something wrong with the arm - how much does it need to move to start pumping? I cannot believe all three of the pumps I have (including the new one) do not work.

[E_T_V]

You need quite a bit of force to move the lever - are you sure you aren't just taking up the slack when you move it?

[matthewsemple]

You need quite a bit of force to move the lever - are you sure you aren't just taking up the slack when you move it?

That was my concern! In fact that is what I think I am doing. (I must try harder).

[matthewsemple]

Dan was right - the new pump works well if the lever is pushed harder.

Next question - I need to source a new insulation block to mount the pump. Do the Mini ones fit?

http://i.ebayimg.com/images/a/(KGrHq...~~/s-l1600.jpg

[maestro dave]

Dan was right - the new pump works well if the lever is pushed harder.

Next question - I need to source a new insulation block to mount the pump. Do the Mini ones fit?

http://i.ebayimg.com/images/a/(KGrHq...~~/s-l1600.jpg

Funny that , Ive just bought one off ebay on the off chance it might fit my 1.3 maestro , it came today and I found out tonight it does .

[matthewsemple]

The Mini and a Maestro 1.3 both have an A-Series engine so that is a likely match. Has anyone tried to use an A-Series insulation block on an R-Series (or Maxi/Aleggro E-Series) ?

[Doctordiesel77]

I don't know for sure, but think it should be the same, as most of the older British mechanical fuel pumps are the same fitting, the only thing that varied was the operating arm, which could cause some head scratching on occassion.....the thickness of the insulator is quite important as well, too thick & pump will not work effectively, too thin & it will bend the arm/break things in the pump...Is your old one still there to measure from?

[matthewsemple]

I managed to find an old block that was on a spare cam cover I had in the garage. It cleaned up a treat so I have fitted that.

Engine seems to be stuck though because although I now know the pump works (the old one didn't) I am still not getting any fuel through to the filter when I try to start the engine. It is behaving like the battery is flat even though I used it to start another car. So I think the pistons are stuck through lack of use. Now for some penetrating oil.

[E_T_V]

Shove some diesel down the plug holes and leave it overnight. Does it turn at all or is it seized?

[matthewsemple]

I think it's seized. I have ordered some penetrating oil - but I do have some diesel so I could try that too.

[Doctordiesel77]

We've been using some penetrating oil called "super slaks" which seems to be good stuff, it says it has graphite in, I think it came from Kellingley colliery, so it may be expensive to buy..but I sprayed some on some seized up bits and pieces that had been left down the pit for a long time, thinking that it would not have much chance..the next day they freed off without the aid of the big hammer, I was impressed..

[matthewsemple]

Shove some diesel down the plug holes and leave it overnight.

How much is some? A teaspoon, a cupful or a gallon?