fuel pump and fuel relay problem

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boulton37
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fuel pump and fuel relay problem

Post by boulton37 » Mon Jan 27, 2014 5:06 am

need help i have just replaced the fuel pump and fuel relay on my 96 mgf due to it not starting after fiting them it started nice but then i went to start the car that evening it did not start the same as it was before i changed everything can any one help pls
regards new member derek :(

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Re: fuel pump and fuel relay problem

Post by mgfsoldier » Mon Jan 27, 2014 7:04 am

I take you have A) checked it is all firmly connected and b) checked the inertia cut off on the left side near the ecu it's a rubber coated plunger approx 2.5 cm across. If these don't work disconnect the inertial switch and run a piece of wire between the 2 terminals to check it's not the actual cut off at fault as this was the problem on mine and took me so long to find the fault.

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Re: fuel pump and fuel relay problem

Post by boulton37 » Mon Jan 27, 2014 8:19 am

hi there thanks for the info and help new to playing with cars still learning may sound daft but what is the inertia
and thanks agen for the help
i just noticed your near salisbury ? i lived up the road from boscombe dawn for 3 years nice place

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Rob Bell
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Re: fuel pump and fuel relay problem

Post by Rob Bell » Mon Jan 27, 2014 9:20 am

Welcome to the forum Derek :)

When you turn on the ignition, can you hear the fuel pump run to bring the fuel line pressure up?

The inertia switch is a black rubber button mounted on the nearside inner wing (from memory!) inside then engine bay.

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Re: fuel pump and fuel relay problem

Post by boulton37 » Mon Jan 27, 2014 2:29 pm

hi some times i can like a werling sound i was told that it could be 2 things pump or relay so changed both
i know were the button is now do just press once??
cheer derek

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Re: fuel pump and fuel relay problem

Post by Rob Bell » Tue Jan 28, 2014 9:25 am

Yes, just once is enough.

A whirring sound is likely to be the fuel pump priming the circuit, which suggests that the pump is working fine (and the problem is unlikely to be the inertia switch). Equally, it would also suggest that the relay pack is functioning as it should.

What happens when you turn the ignition switch to start the engine: does the starter turn the engine over as per normal?

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Re: fuel pump and fuel relay problem

Post by boulton37 » Tue Jan 28, 2014 10:03 pm

hi when i turn the key it trys to start as normal but dosent start when i changed the relay at first it started this was before i changed the pump then the next morning it did the same tuned over but never started so got another relay same agen started no allways do i hear the pump start to prime ?
reGARDS DEREK

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Re: fuel pump and fuel relay problem

Post by daz » Tue Jan 28, 2014 10:51 pm

sounds like something is damaging the relay, can you prise the top off one of the faulty relays to see how it looks inside? I'm not sure if there's a way to bridge the relay or make the pump run constantly to see if it starts up then.

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Re: fuel pump and fuel relay problem

Post by boulton37 » Wed Jan 29, 2014 2:40 am

CHEERS WILL TRY GOT 3 DAYS TO PLAY AFTER THIS SHIFT LET YOU NOW HOW IT GOES

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Re: fuel pump and fuel relay problem

Post by Rob Bell » Wed Jan 29, 2014 11:12 am

Taking the cover off is a good idea as you should be able to get a good view of the operation of the relays when you turn the ignition on and attempt to crank the engine.

Next question: is fuel actually getting the the fuel rail? Could this be something very simple like a blocked fuel filter? I haven't changed mine in 18 years and 110k miles and there is a good chance yours will be the original too...

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Re: fuel pump and fuel relay problem

Post by boulton37 » Thu Jan 30, 2014 9:46 pm

relay is ok tried a new fuel cut off switch so up to naw
hi al tried the following and still the same chain of events
1 new fuel pump replaced
2 new relay replaced
3 new fuel cut off switch replaced
4 tried with fuel cap off
5 batt dead lol
any more ideas peeps getting very annoyed lol

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Re: fuel pump and fuel relay problem

Post by daz » Thu Jan 30, 2014 10:08 pm

so, whenever you replace the relay it starts OK, until the next time you try to start it? Can you take the cover off the fuel pump & get someone to turn the car over while you check to see if the fuel pump is working? If it works, the next thing I'd do is disconnect the pipe to the fuel rail to see if it's actually pumping fuel, be very careful the petrol will come out VERY fast. If you can, fit another pipe to the connection & put the other end into a container to catch the petrol that should come out. If the fuel does come out you need to check the fuel rail is getting petrol, if it isn't there is a blockage somewhere, fuel filter is the first port of call then.

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Re: fuel pump and fuel relay problem

Post by boulton37 » Tue Feb 04, 2014 4:06 pm

hi all OK i got the car started after all the changes been for nice drive on the moors. and stopped and started no problems after putting a new battery on the car .but now i have noticed that the stereo cuts off and the engines management light flits on only for 2-3 secs??? any ideas pls
regard derek

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Re: fuel pump and fuel relay problem

Post by Rob Bell » Tue Feb 04, 2014 6:40 pm

It must be Gremelins Derek! :lol:

Actually I'd be worried about chaffing wire behind the dashboard - there was a recall over this about 12 years ago - so it would be sensible to look carefully at this. An alternative explanation is a poor connection to the main passenger compartment fuse board?

BTW, a 1996 MGF doesn't have an engine management light. Is what you are seeing a charge warning light coming on?

boulton37
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Re: fuel pump and fuel relay problem

Post by boulton37 » Tue Feb 04, 2014 11:36 pm

cheers will have a look look so could it be a loose wire down there ? still learning lol you say behind the dash were would i look
regards derek and my gremlins
thanks agen

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Re: fuel pump and fuel relay problem

Post by boulton37 » Mon Feb 24, 2014 4:11 am

hi guys just a quick 1 when i fill my car now it seem to struggle geting the fuel in the tank the pump keeps clicking off very anoining also i get blow backs of fuel on me
cheers

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Re: fuel pump and fuel relay problem

Post by daz » Mon Feb 24, 2014 10:32 am

You need to turn the nozzle 90 degrees when you push it into the filler neck

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Re: fuel pump and fuel relay problem

Post by Rob Bell » Mon Feb 24, 2014 10:41 am

Is the fuel tank breather blocked??? If there is a significant vacuum being generated in the tank due to a blocked breather, fuel delivery will be diminished.

Do you always notice that the car is easier to start when the fuel filler cap has been removed and replaced? Is there a significant "whoosh" noise when the fuel cap is removed?

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Re: fuel pump and fuel relay problem

Post by boulton37 » Tue Feb 25, 2014 10:48 am

hi yes there is a large whoosh i have just put a new fuel pump in the car and a mew pipe too mat have a kink in the pipe i have a look cheers

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Re: fuel pump and fuel relay problem

Post by boulton37 » Sun Mar 23, 2014 7:23 pm

hi all thank for your help with the fuel pump and realy problem
go 1 more now my heater keep going on and off but today it has stoped all together! i have changed the 20 amp number 19 fuse but still not working still know blow any idea s pls
regards derek

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