Possibly Faulty Fuel Pump

[proaxis2 0]

So looking for some reassurance really before I shell out for new fuel pump.

 

I've got a 92 1.6 with an Mi in. Had a trackday back at Easter at Bedford and on some of the corners it was cutting out slightly, never stalling just loss of power, it seemed to cure itself throughout the day. Tank was three quartes full by the way.

 

Anyway had a great day, came home and put car away, but due to holiday and work I didn't get chance to run it for a month or so. It started fine, however got 100 yards down the road on a slight up hill and it cut out and then wouldn't start for ages, however got it back on the level ground and it started again and it was fine, would tick over but still splutter a little when you revved it.

 

I'm thinking fuel pump but after a hour or so of searching on here it could be Ignition Amp, or Fuel pump relay. Got a new (2nd hand) Ignition Amp, fitted it and it only ran on three cylinders, so put the original back on and it ran fine.

 

Then this evening got the multimeter out put it on the leads to the pump to make sure it was getting a feed when I tried to turn it over and it was getting a constant feed. Then better still I took it for a drive with the multimeter still connected to see if the voltage dropped, when the car cut. It didn't, so surely this has to be fuel problems rather than electrical?

 

The pump does seem to be making a larger hissing noise than what I remember, but as you can tell it's not as if I drive it every day.

 

I can't really do the test of taking the cable off the fuel rail either as like I said it starts and ticks over fine.

 

Any one got any ideas or do all fingers point to the pump?

 

Any advice appreciated.

 

Cheers

 

Adam

[Trick 1]

I guess from the fact that the pump has constant voltage then the relay is ok?

or maybe its sticking? can you remove it and test?>

[proaxis2 0]

I guess from the fact that the pump has constant voltage then the relay is ok?

or maybe its sticking? can you remove it and test?>

 

Yes that's what I'm thinking, that the relay is OK.

 

Remove which the relay or pump?

 

Wierd though as I hunted for the relay but couldn't find it anywhere around the ECU, removed the lower part but is it a complete dash off job to get to it?

 

Cheers

[pug_ham 245 3 Cars]

I guess from the fact that the pump has constant voltage then the relay is ok?

Once the engine is running the pump always has a constant 12v supply from the relay. If its not there when the ingnition is switched off the relays sounds to be OK but that doesn't mean it is. If you can borrow a known good one or have a spare, swap it & see if its fixes.

Wierd though as I hunted for the relay but couldn't find it anywhere around the ECU, removed the lower part but is it a complete dash off job to get to it?

With the lower dash off & an open view of the ecu the tachy relay should be bolted to the top ecu securing stud unless your car is an early phase 1 with the relay in the engine bay in front of the battery tray.

 

Graham.

[proaxis2 0]

Once the engine is running the pump always has a constant 12v supply from the relay. If its not there when the ingnition is switched off the relays sounds to be OK but that doesn't mean it is. If you can borrow a known good one or have a spare, swap it & see if its fixes.

With the lower dash off & an open view of the ecu the tachy relay should be bolted to the top ecu securing stud unless your car is an early phase 1 with the relay in the engine bay in front of the battery tray.

 

Graham.

 

 

Nice one cheers Graham

 

It's a phase 2 so will have a look with eyes open this time.

[proaxis2 0]

OK so spent most of this evening looking the bloody tachy relay, including laying on my back in the footwell looking up after removing the ecu.... and still can't find it.

 

After reading this: http://forum.205gtidrivers.com/index.php?s...&hl=bx+loom

 

I've come to conclusion that when the BX 16v engine and loom was put in the tachy relay was removed.

 

Which then points my problems to the pump?

 

Any thoughts?

 

Cheers

[Toddy 7]

That is fuel starvation on track as you need to keep the tank as full as possible, some cars suffer others don't.

 

The Mi does not use the tacho relay, on a BX the fuel relay is brown from memory and about one inch square this is normally situated in the engine bay unless the relays have been moved by the person doing the install

[proaxis2 0]

That is fuel starvation on track as you need to keep the tank as full as possible, some cars suffer others don't.

 

The Mi does not use the tacho relay, on a BX the fuel relay is brown from memory and about one inch square this is normally situated in the engine bay unless the relays have been moved by the person doing the install

 

 

Yeah I had three quarters of a tank on track though so was maybe the beginning of the problems I'm getting now.

 

Excellent thanks for confirming that. I've found the Brown one in the engine bay, I did think it could be it but wrong colour and different code to the 8v tachy relay.

 

Anyway I've managed to source a pump cheaply so I'll change that to see if it cures it but same time try and source a new Brown relay too.

 

Cheers

[proaxis2 0]

Finally got it sorted. Nothing to do with the fuel pump...

 

I changed the the dizzy cap and rotor arm just in case and no difference.

 

Then got another Ignition Amp through, tried that and bingo worked fine.

 

However it still hesitates when feathering the throttle, and it appears if you feather it for a while under load and warm it cuts out and won't restart for a while.

 

At least it goes above 2k now though!

 

Adam