BMW 5-Series E34 (1987 - 1996) - Omega 2.5td pump to bmw 525td

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Mon 13 Aug 2007 09:41
Omega 2.5td pump to bmw 525td - dbastille
Hi john,

Can I pick your brains on this one. Have you ever heard of an omega 2.5 td pump being used in a bmw 525td? What we did [foolishly] was by a replacement omega engine 2.5 td from a 97 model and shoved it into a bmw 525td 95 model [engine and all]. All the connectors were the same and we thought it would work. Not so, we were then told by the local injection pump reconditioner that they are different. Is this true ? and have you ever heard of anyone doing this conversion to make their bmw run?
We are now stuck with an unusable bmw 525 td in good nick but....hope to get it working.
Many thanks

{Post reformatted to remove the overdose of >>>> symbols - DD}
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Mon 13 Aug 2007 10:15
omega 2.5td pump to bmw 525td - cheddar
Cant help directly though IIRC the 525td was non intercooled and 115bhp, the Omega was intercooled and 130bhp and the 525tds was intercooled and, I think, 143bhp. So it seems that there must be injection pressure / timing differences.
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Sun 7 Oct 2007 08:47
omega 2.5td pump to bmw 525td - HarlequinVW
Did you have any success with this?

I've just put an intercooled 2.5 from a 525iX in a non-intercooled 525 td. I didn't fit the intercooler in the end because it was full of holes. So i have an intercooled engine, without the intercooler. I could change the fuel pump over from the old non-intercooed engine though. The pump do seem to be a bit different.

My problem at the moment is that i can't get it started. I can't seem to prime the injector lines. The lift pump works, although the delivery presure seems low, you can stop it by blocking the fuel line with your finger. Although this doesn't seem to matter as the returns from the injectors and pump to the tank seems open, with no restriction to overcome. The priming pump system seems to need flow, but no presure.

The high pressure outlets from the pump seem less inclined to self prime, we've tried for ages on the starter and tried towing it. The upturned U form of the injector lines doesn't seem ideally suited for removing air either. Trying to keep the injector fuel lines attached to the pump and full would be my advice here. Maybe it just takes ages to prime, or i'm missing something?

Any ideas, anyone?
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Sun 7 Oct 2007 13:56
Omega 2.5td pump to bmw 525td - injection doc
What your pump specialist is quite true & they do differ & it wont run. The spec's are bery different & so are the electrics involved.
Doc
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