starting issue

[T5frankie]

i had to change the in tank fuel pump on my 740t, now the car starts every time but dies straight away, ive had the pump back out and tested it and it works, dunno if its a co-oincidence but i also changed the leads. dizzy/rotor arm whilst in the middle of doing the pump but i thought any problem there would cause rough running, doing my head in now as running out of free retest time, and you also have to be double jointed to do this job

[merc85]

Could be the fuel pump relay mate, ive just sold one of these to a customer who had exactly the same issue, and it sorted it

[T5frankie]

Could be the fuel pump relay mate, ive just sold one of these to a customer who had exactly the same issue, and it sorted it

on a 740?

[merc85]

on a 740?

yes a blue 740 turbo intercooler estate, Manual too

[AAnickmac]

these are really common as a breakdown. i thought it was a green relay behind radio area. but may be blue in colour.

[merc85]

these are really common as a breakdown. i thought it was a green relay behind radio area. but may be blue in colour.

The one the gentleman had in my shop was a white relay, cant remeber the part number of it tobe honest.

[T5frankie]

i know its common on 850's, will try that dunno why it should suddenly go as i change the pump though

[stribo]

Could be the fuel pump relay mate, ive just sold one of these to a customer who had exactly the same issue, and it sorted it

The one the gentleman had in my shop was a white relay, cant remeber the part number of it tobe honest.

I hope you're not pushing your business.

[MoleT-5R]

i know its common on 850's, will try that dunno why it should suddenly go as i change the pump though

may be your new pump is drawing more power though the old relay than the old tired one did....just a thought

[merc85]

I hope you're not pushing your business.

no im not, but as a registered trader on here, if i feel the need to i can.

[MoleT-5R]

I hope you're not pushing your business.

stirrer.......lol

[t5 pete]

Yeah the relays are bad had the same problem on the 240 but in my case it wouldn't start a quick bash to the relay and it would be fine its the solder inside of them that goes dry I re soldered mine and was all fine.
One thing to do frank is get some one to start it while you listen for the pump and see if it cuts out once its started

[T5frankie]

may be your new pump is drawing more power though the old relay than the old tired one did....just a thought

i tried the new one and the old one as it wasnt actually the pump that went just rusted through joints, they both work,
i ran a live straight from the battery to the pump worked but still didnt stay running

[MoleT-5R]

i tried the new one and the old one as it wasnt actually the pump that went just rusted through joints, they both work,
i ran a live straight from the battery to the pump worked but still didnt stay running

so if I'm reading this right, you've got 2 duff pumps then ??

[T5frankie]

so if I'm reading this right, you've got 2 duff pumps then ??

no you're not reading it right, i have 2 good pumps

[oblark]

these are really common as a breakdown. i thought it was a green relay behind radio area. but may be blue in colour.

The fuel pump relay is also the ignition relay.

If my memory is right the fuel pump side of the relay comes in first then the ignition side comes in and it is behind the radio.

So if the fuel pump side fails then the ignition will not come in.

[MoleT-5R]

no you're not reading it right, i have 2 good pumps

so why do they stop pumping when as you say "i ran a live straight from the battery to the pump worked but still didnt stay running" or do you mean the pump continued to run but the ignition cut

[stribo]

stirrer.......lol

me? never

[T5frankie]

so why do they stop pumping when as you say "i ran a live straight from the battery to the pump worked but still didnt stay running" or do you mean the pump continued to run but the ignition cut

I didn't say they stopped pumping just my car won't run for more than a second

[MoleT-5R]

I didn't say they stopped pumping just my car won't run for more than a second

but you didn't say that when the car cut out, the pump was still working, but all that aside it looks like an ignition fault afaik