Tachymetric Relay & Pump Issue

[soundguy 13]

Hi folks, have a problem with no priming from the fuel pump and what seems to be no activity in the tachymetric relay. I should state, that I think the fuel pump could be seized as it's been noisy over recent weeks - but I need help in determining why the tachy relay doesn't seem to be working.

 

Drove the car today, parked up for a short while then when I went back to it, it wouldn't start. Couldn't hear the priming whirr at all while I tried to restart, and still won't after having the car recovered.

 

Got a question first about the tachy relay - I opened it up but there's no sign of any damage to any components or coil. Contacts are clean, nothing burnt out, tracks OK on rear. I plugged it back in without the case on the relay and turned the ignition to the prime. Then I used a small screwdriver to make the relay contact.

 

When I did that I could hear the pump trying to work - one click then nothing. Tried this a few times, same result.

 

So the question is, why doesn't the tachy relay energise and make the contact?

 

The AA guy took a direct 12v feed with a fuse to the pump and could hear it trying to trigger but wouldn't prime. Could the pump failing somehow cause an additional fault which affects the tachy relay? Like, could a fuse which supplies the tachy relay be blown by a seized pump drawing a load of current, or something similar?

 

Just want to figure out what I need to replace rather than both the pump and the relay.

[Tom Fenton 1,548]

Some 205's do the "prime" thing, others don't, so certainly don't worry too much about this.

 

I would concentrate on fitting a new fuel pump first.

[soundguy 13]

Some 205's do the "prime" thing, others don't, so certainly don't worry too much about this.

 

I would concentrate on fitting a new fuel pump first.

 

Fuel pump ordered and on it's way. Will update the thread once it's I've replaced it, which should be tomorrow.

[Weser 30]

Just a quick question as its sort of on topic. How does the prime function work? My 205's both do it. However my Dad has a cti which now doesn't prime. He had some problems with his electric roof tuned out to need a new oil pressure switch. We took loads of things apart testing to find out how the roof worked. He swore to me that it used to prime before we played around with it. Now it definately doesn't. It could be that he is getting on and is forgetful but I thought as this has come up I would ask the question on how the priming works?

[soundguy 13]

Just a quick question as its sort of on topic. How does the prime function work? My 205's both do it. However my Dad has a cti which now doesn't prime. He had some problems with his electric roof tuned out to need a new oil pressure switch. We took loads of things apart testing to find out how the roof worked. He swore to me that it used to prime before we played around with it. Now it definately doesn't. It could be that he is getting on and is forgetful but I thought as this has come up I would ask the question on how the priming works?

 

The priming can usually be heard as a short buzz in my case. It's the process of the fuel pump filling itself up with fuel before the engine is turned over on the key. Probably stops the air or bubbles being sent down the fuel line, but definitely prolongs the life of the pump too as it will use fuel as a lubricant.

 

The pump probably gets a short burst of energy from the fuel pump relay before the key is turned to the ignition point. Don't know if that answers your question - but you can usually hear prumps priming, that's how you can tell when it's happening.

[soundguy 13]

Some 205's do the "prime" thing, others don't, so certainly don't worry too much about this.

 

I would concentrate on fitting a new fuel pump first.

 

Right, new fuel pump was fitted yesterday, then I flattened the battery trying to get it to start. Charged it overnight, stripped the pump and housing down to make sure everything's in place and it still won't start.

 

I can hear the pump prime and the engine will turn over. However, after taking the fuel lines off the top of the pump housing, they are both dry inside. When I took the old pump off, a few drops of fuel came out - now they're bone dry.

 

Incidentally, the housing won't go back together as it was, because the new pump is smaller - but the strainer is definitley sitting in fuel, and the pump is secure in the housing - I've had the pump and housing out three times now.

 

Has anyone been through this before, fitting a new smaller pump into the housing? Comes with a neoprene sleeve and a rubber boot but can't get everthing to fit togther anymore, so have left some of the flanges/caps out - but, it's secure in the housing and the filter is sitting in the fuel.

 

Could the new pump work 'backwards' - ie, should I reverse the pipes on the top of the housing? The + and - signs are in the same place as the old pump, pale blue wire goes to right terminal spade, yellow/green goes to left, with the fuel pipe behind and between the two.

 

Incidentally, listed as a DA-25 on fleabay:

 

http://www.ebay.co.uk/itm/DA-25-FUEL-PUMP-FITS-PEUGEOT-106-205-GTi-16s-/160593309439?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item25641b6eff#ht_4167wt_1110

Edited October 28, 2011 by soundguy

[soundguy 13]

Ok, got the fuel pump working as it should, made it sit a lot lower in the housing as the actual pump is shorter and smaller diameter than the old one. Ater the last attempt to start I took the fuel outlet pipe off the top of the housing and a small amount of fuel flooded out.

 

So that proved the pump is pumping - but it still won't start and I've just cranked it until the battery's flattening again (charging as we speak).

 

The engine was running fine before the old pump seized. The AA guy who recovered me last week removed the air filter housing and squirted some sort of quick start into the AFM and the car started and ran for a short while before he confirmed the seized pump.

 

Is it possible that the new pump isn't up to the job (according to sellers website, capable of 255 litres an hour), but can move fuel down the line? If it is, what's next? Blocked fuel line? Should I disconnect the fuel rail? Need to do a 2 1/2 hr journey this afternoon, running out of ideas!

 

Any help appreciated.

Edited October 30, 2011 by soundguy