SU Petrol Pump Problems

Post by **PaulJohnson** » Sat Aug 02, 2003 2:09 pm

Hello Everyone.

I was coming back from Manchester over the Snake Pass when my moggy went down from 50mph to 30mph, It then jumped a bit and then regained its power again.
I thought it was all the rain that had got into her must have done somthing.
However when I was doing a trip into Sheffield there was a noise started from the front left (Screching) was I right in thinking that we have petrol pump problems?.

I have just looked in my many Moggy manual`s that I have and I have to take of the end cover and run a strip of paper over the contact breaker to clean it, then I have to undo the filler underneath, if I do this will unleaded leak out?.

I have also been told that if I take the 6 scews out from the side of the pump I can see if there is a blockage, But again do i have to take pecautions for leaking fuel??.

Hope you can HELP.

Best Wishes Paul

Post by **les** » Sat Aug 02, 2003 10:58 pm

Sorry Paul, wrote a reply got an invalid entry, will try again tomorrow.

Post by **les** » Sat Aug 02, 2003 11:15 pm

The noise you describe is a new one on me, for a petrol pump. If u undo the filter housing plug u will lose some fuel, but as the pump is higher than the tank this shouldn't amount to much. unless u suspect a faulty diaphram dont touch the 6 screws, they hold the two pump halves together and if undone a procedure has to be adopted to tension this diaphram on assembly. The points can be cleaned as u say by useing wet and dry paper, this is the usual area of problems on the su pump. Precautions include the obvious!

Post by **Cam** » Sat Aug 02, 2003 11:18 pm

It sounds like your pump. If you undo the filter (bolt) then unleaded will pour out, but if you have a rag under it it will catch it.

It does sound like it may be sticking points (on the pump), so clean them first and see if it happens again. If this does not cure it, then most people just get another pump, but you can strip and rebuild it if you like.

Post by **Cam** » Sat Aug 02, 2003 11:18 pm

oops sorry, Les, posting at the same time again!!

Post by **les** » Sat Aug 02, 2003 11:27 pm

That's cool.

Post by **PaulJohnson** » Sun Aug 03, 2003 1:29 am

Thanks Cam & Les!!!

I have a plan B !

Some nice person is selling a SU Fuel pump on e-bay so Iam bidding on it at the moment, if need to change a part I can take it off of the e-bay pump (So no bidding!!!)

Iam not sure how long pumps are supposed to last but with all these hills in Sheffield I have probably worn it out?.

Best Wishes Paul

Post by **PaulJohnson** » Sun Aug 03, 2003 1:37 am

You can tell it`s early in the morning Cam & Les !!
I will be doing all the checks on Monday (day off) as Today Iam back at work after my 2 week holiday (No Comment!!)

Post by **Chris Morley** » Sun Aug 03, 2003 1:59 am

It's very likely that it's just the points as Cam said. Checking the fuel filter is simple and quick (I do it during every service). Ensure the ignition is off. Remove the battery if you feel nervous, so that there is no chance of a spark. Then hold a rag underneath when you undo the filter - no more than a half as teaspoon of petrol will leak out.

Buying a new fuel pump before you find the cause of the fault is probably going to be a waste of money.

Post by **PaulJohnson** » Sun Aug 03, 2003 2:16 am

Thanks Chris!
Nice to see someone else is up at this hour.

Dont worry about me wasing money, Im a Yorkshireman
At the moment the pump is going at £5.09p If it go`s more than £10 I will be breaking out in a sweat.

Thanks Again

Paul

Post by **Kevin** » Sun Aug 03, 2003 9:40 am

Paul all good advice however a screeching sound does not sound like a fuel pump but either a slipping fanbelt, dry dynamo bush (unlikley to squeal that loud) or a water pump, I am not saying that you dont have a fuel pump problem just that I dont see how the screeching noise relates to the fuel pump.

Post by **grainger** » Sun Aug 03, 2003 12:58 pm

mmmm thats what i didnt understand ? does the petrol pump squeal when its breaking down ? i thought they just stopped or ticked like mad

cheers
grainger

Post by **PaulJohnson** » Sun Aug 03, 2003 3:14 pm

The sound is comimg from the front left & if you open the glove box you can hear it more.
I have checked the fan belt it`s ok.
Best Wishes Paul

Post by **Willie** » Sun Aug 03, 2003 9:32 pm

well,that's a new one,if your wipers were not on at the
time of the screeching then you probably have the first
screeching petrol pump that any of us have ever heard
of!! Let us know what cures it so that we can file it in
the memory for future use. When you clean the pump
points it is useful to know that the outer contact blade
slides out for cleaning as soon as you loosen the screw.
I.e. it is not necessary to remove the screw completely.

Post by **Chris Morley** » Mon Aug 04, 2003 12:26 am

There aren't many moving parts in the pump and I can't see how they could make such a noise. Assuming of course you have the standard SU pump - aftermarket replacements are not unknown.

One thing that does screech on a Minor (very loudly) is the later heater when switched on (or within a few seconds). Could this be the cause?

Otherwise the only other item near the L/H glovebox is the wiper motor. If this screeched I doubt the noise would stop. Also consider that a loose electrical connection can cause a similar loss of power to fuel starvation. Check for loose connections, especially to the coil and the fuel pump itself. I've had a spade connection to the coil come loose when the engine was working very hard, causing a loss of power.

Post by **Cam** » Mon Aug 04, 2003 12:42 am

I have had a petrol pump screech (well it was more of a loud buzz really), this was after it had stopped and I was starting the points by hand and blocking their proper return. It did not do it for very long before it was back clicking again.............

Post by **PaulJohnson** » Mon Aug 04, 2003 3:48 am

To Wille & Chris

I did not have my wipers on when it started to screech

Iam 90% sure it is the fuel pump because as I said in my first post I was doing about 50mph then the car lost power went down to 30mpm jigged & splutted a bit and then came back to life, it was at this point when the noise first started, Also this morning (1am) when I was comimg back from work as I was going up hill you could hear the noise it is coming from the pump and tends to only now happen when the pump has to work hard.

Also to Cam: when your pump made a noise were you going up hill?.
Maybe people like you and me who live in the hilly area`s need to stock up on fuel pump parts?.

Thanks to everyone who has posted, I will go over the moggy later today and tell you what i find.
Thanks Again
Paul

Post by **PaulJohnson** » Mon Aug 04, 2003 3:59 am

Im not going to add a smilefrom the front left of this page as someone has just out-bid me on the SU fuel pump on e-bay

Looks like the collection boxes are out again (Cam)

You should know the saying about Yorkshiremen & Money!

Post by **stephen** » Mon Aug 04, 2003 8:10 am

I'm intrigued as to how the SU pump would cause you to lose power. It either works or it doesn't so the car will either drive or stop. In your case the car kept running (albeit with reduced power).

Does your car lose power when the noise occurs?

Post by **Cam** » Mon Aug 04, 2003 1:05 pm

Paul,

No, I was not going up a hill, It stopped and I took the end of the pump off and started to free the contacts by hand when the 'buzzing' happened, but I suppose it's possible for it to do it on it's own!?

I know about the e-Bay bidding, and it's not good..... I have been bidding on a data sheet for a series MM carb, and have been beaten to it by 'sparesman' who is actually Brian Gosling (the MMOC spares supplier). It's a bit annoying, as I would have used it as a data sheet, and he will just make money out of it.

Stephen,
If the pump goes off (or reduces feed pressure) for a brief time, then the float bowl can't fill up, and so it starves the engine of fuel briefly, causing a brief reduction in power. Like you, I would have though that it would just stop, but I have had it happen a few times and it does sometimes just cause a brief reduction in power.