Think my Fuel pump is broken

RossM · Post by **RossM** » Thu Dec 17, 2009 11:43 pm

Well got the dexta into a driveable state since stripping down for respraying so we started her up for the first time in 2 weeks. After a few cranks she fired and idle, a few rev ups and then suddenly she just revved out of control and just kept getting faster and faster, pull to stop had no effect, turned the fuel off but this didn't stop her. My mate jumped on in the end and managed to stall her. THe exhaust has burnt all the paint black it got so hot.

Any ideas, governer maybe?

Looks like she's going to be towed to the church on the wedding day as I can't see this being fixed in the next week.

pottyperkins · Post by **pottyperkins** » Fri Dec 18, 2009 12:27 am

Hi sorry to hear your having more set backs
If you think its diesel related phone diesel bob 01254 878 582 near longridge , im told he is very good
hope he can help

RossM · Post by **RossM** » Fri Dec 18, 2009 8:19 am

damn good idea pottyperkins, i'll give him a ring this morning to see what he thinks.

one thought i had was that it could be diesel drawn in through the pipe going to the heater in the manifold but i'm sure the tap was closed.

I think i'll be sticking her on a trailer and parking her outside the church and i'll pretend I drove her there!

jambug123 · Post by **jambug123** » Fri Dec 18, 2009 10:31 am

that sounds like the govenor weights have stuck or a bad head gasket seal fault it could of been running on its own engine oil.

Regards
James

Ian · Post by **Ian** » Fri Dec 18, 2009 11:12 am

Diaphragm in the fuel injector pump perhaps

RossM · Post by **RossM** » Fri Dec 18, 2009 11:29 am

the head gasket idea has crossed our minds, however the engine has been fully rebuilt with machined block and machined head and new gasket, bnut that doesn't mean its not the problem

as for governor diaphragm, its the mechanical version on a super dexta so it doesn't have one. weights however could be it. any ideas how to check the weights?

RossM · Post by **RossM** » Fri Dec 18, 2009 12:28 pm

just spoken to www.sjwilkinson.co.uk who are actually only down the road from where the tractor is currently stored. They will happily look at it but close on wednesday for xmas so i need to get it there quick.

he thought that seeing as the pull to stop didn't work it could be that the engine started to run on its oil.

sounds expensive.

Aussie Frank · Post by **Aussie Frank** » Fri Dec 18, 2009 12:36 pm

Hi Ross,

One thing is for sure if you drive her in the current state you won't be late for the wedding. Just make sure you have the stopping bit worked out. Personally I would check the cold start feed though, as I had a similar problem on my P6 a while ago. It doesn't take much of a leak to make them run like a bat out of heck and the fuel in the lines is enough to keep them running for what seems like forever.

Good Luck, Frank.

RossM · Post by **RossM** » Fri Dec 18, 2009 12:47 pm

Its certainly worth a look at.

RossM · Post by **RossM** » Fri Dec 18, 2009 5:01 pm

Just had a moment of inspiration!

This is the first time she's run with an air filter! Could she be sucking oil in through the air inlet via the oil bath filter????

I'm clutching at this straw. Monday when i go to the lock up i'll disconnect the air filter and see if there's oil in the inlet manifold and fire her up. I'll say my prayers tonight!

Post by **Brian** » Fri Dec 18, 2009 5:25 pm

It is either a fuel pump problem or have you checked the engine oil? If you have a diesel leak into the sump that would give those symptoms.

You have a different cold start mechanism on her, if that sticks she will start and run for a few minutes, then stop and you won't be able to start her.

Take the side plate off the pump and see if the rack has stuck before going in too deep.

RossM · Post by **RossM** » Fri Dec 18, 2009 6:06 pm

Brian, i'll check the pump but i'd have thought that pulling the stop would have stopped the engine but it didn't. I checked the oil level and it seemed normal and the oil was clean looking.

I might disconnect the diesel feed to the air manifold too to rule this out.

Post by **Brian** » Sat Dec 19, 2009 7:02 pm

If the rack was stuck in the maximum position, the stop might not have worked but also, if she was pulling diesel through the heater you would get the same results. I would have expected white or black smoke earlier rather than a sudden change.

Your aircleaner should not make any difference to the governor. If it was restricting the air flow she should "choke".

Disconnecting the heater fuel pipe and running her should answer your question. Have a metal cap ready to drop over the air cleaner to stall her out though.

Another thought, you had not used petrol to clean the air cleaner had you? Residue left in the wire gauze can do funny things.

RossM · Post by **RossM** » Mon Dec 21, 2009 11:56 pm

disconnected the air filter and started her up. she ran fine!

Post by **Brian** » Tue Dec 22, 2009 8:52 am

The air cleaner does no affect the pump on a mechanical governor so it must be either something in the air cleaner like reside or the extra suck when the air cleaner is fitted is pulling diesel through the heater. Have you a tap on your heater line? Most Super Dextas should have one.

RossM · Post by **RossM** » Tue Dec 22, 2009 11:11 am

There is a tap in the heater fuel line and that is closed. The inside of the air inlet manifold was coated in oil.

pottyperkins · Post by **pottyperkins** » Tue Dec 22, 2009 7:35 pm

Hi, i seem to remember someone had a similar problem with a grey ferguson fitted with a p3 engine. it turned out the whole air cleaner was mounted to high up and it sucked the oil out, it was lowered and the problem was solved.
howerever its not as easy with the dexta because it mounted under the bonnet