P38 omega / bmw pump similarity

Hi all, got a 1996 2.5 P38 which i need to change the pump on at some point as i have a fuel quantity actuator fault and hot start problems, so my question is, are the pumps from the 325 / 525 tds and omega the same? i have read differing opinions on the matter. some say the electronics need swapping over but i'm guessing some of my problems lie with the electronics so that may be counter-productive?
if anyone can shine some light on it that would be ideal

Cheers
Adam

Hi

Have you checked all the other options and had connected to a diagnostics, i have the a fuel quantity actuator issue but i am sure it's not my pump, but that is what is displayed on a diagnostics.
I suspect it's number 4 injector.
but as for pump similarities i can not answer that.

Do a search, there are a lot of threads on this subject. The electronics are different and the mounting boss size varies but in priciple the pump is the same and the electronics can be swapped.

Bazbar, as in OP and my post in your topic, i have the same fault as you, but also had a different fault with number 4 injector so this was replaced, the injector fault went but the injector light coming on on decelleration is still there so number 4 injector can't be causing the fault.

Datatek, i have searched and found the info about different pump flange sizes and the electronics possibly needing to be swapped over, but half my question was if i swap the electrics over am i taking the fault with it, i.e is my fault within the electronic or mechanical side of the pump. i suspect it may be both. i have a fault coming up for fuel quantity actuator, but also have the problem with hot start and juddering at low speeds.

Many thanks
Adam

aniesigh said:

Bazbar, as in OP and my post in your topic, i have the same fault as you, but also had a different fault with number 4 injector so this was replaced, the injector fault went but the injector light coming on on decelleration is still there so number 4 injector can't be causing the fault.

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I've found that the engine light coming on when you lift off is a crank sensor fault, not a no.4 injector fault.

On the over-run the EDC cuts off fuel supply so the no.4 injector does not return a reliable engine rev. The EDC knows this and goes to the crank sensor looking for a rev count. If it doesn't get one it logs a fault, flashes a fault and goes into recovery mode.

I had an intermittent fault in the no.4 combined with a faulty crank sensor. Often mine used die completely, especially when cancelling cruise control. I used have to put my foot on the accelerator before cancelling cruise to prevent finding myself stuck in the fast lane with a dead rangie.
Changed both sensors problem gone completly for several years.

The flash of the light is back now but without cutting out so I'll be replacing my crank sensor at Christmas.

the only difference in the pumps is the flange size, the multi plug is the same and the pumps are not coded. the hot start is caused by mechanical wear in the lower section of the pump where as the fual quantity control is in the upper section so it sounds like you need a new assembly. i have found with recon pumps they only replace the upper section but cant do anything for the worn lower mechanical side of your pump so the hot start will probably still occur but it will cure you fuel quntity fault. keep looking through ebay regular as new ones some times pop up, i bought a brand new one from duckworths when i had a p38 for 235 quid, new old stock. cured all the problems, the diffence was like night and day in driving it.

thanks for the replies, ABU i thought that would probably be the case, is there a way of knowing which models of BMW had the different flange sizes? and which size is the RR one? if i was planning to keep it for a long time i would buy a recon one, but will probably sell next year but don't want to sell it with a fault.

Spud. thanks for that, how much is a crank sensor? none of the usuals have them listed (paddock/island4x4/Johncraddock/ebay etc) haven't rung anyone yet but be nice to have an idea.

cheers

aniesigh said:

Spud. thanks for that, how much is a crank sensor? none of the usuals have them listed (paddock/island4x4/Johncraddock/ebay etc) haven't rung anyone yet but be nice to have an idea.

cheers

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TT Automotive

www.ttauto.co.uk

Worth giving them a ring, I've found them really helpful in the past

if you advance the timing on your pump it should compensate for the wear mine used to be very hard to start when hot i moved the pump about 2 mill and now starting first tip hot and cold it also gave me a big difference in power i have a bmw 525tds engine fitted to mine with the bmw pump with rr electric top if you change the top onto another pump you will see that it slides about until you tighten the bolts the reason it slides is because it is timed your vehicle might rum erratic or rev high but if you play around with it you will get it perfect as i did.

seanmull said:

if you advance the timing on your pump it should compensate for the wear mine used to be very hard to start when hot i moved the pump about 2 mill and now starting first tip hot and cold it also gave me a big difference in power i have a bmw 525tds engine fitted to mine with the bmw pump with rr electric top if you change the top onto another pump you will see that it slides about until you tighten the bolts the reason it slides is because it is timed your vehicle might rum erratic or rev high but if you play around with it you will get it perfect as i did.

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Don't think sliding the pump top alters the timing, it changes the fuel quantity.

:doh: im wrong and wammers is right it does alter the fuel quantity it does not effect the timing. thank you wammers .