W123 300D NA: Fuel system rebuild = power!!

[Screwdriva]

Just installed Greazzer rebuilt injectors with Monark 261 nozzles (increased pressure setting by 150 psi vs. the injectors I supplied), rebuilt lift pump and OFV spring.

While these injectors we're not in as bad a shape despite the 140K odometer reading, the difference is much more noticeable in the W123 300D (vs the W115 240d from last year). Power through the rev range has shot up. Car feels like it has got an extra 10-15 bhp - I can't prove it ofcourse but it revs with much more ferocity than before. Unlike the W115 which idled quieter, revved in a more refined manner and became more economical with little difference in power, initial improvements with the W123 are primarily a substantial increase in diesel power and a quieter low rpm behavior. Economy will be measured.

All in all, highly recommend replacing the OFV spring, rebuilding lift pump and injectors with German made parts.

[g300d]

OFV?

Hmm, I want to try all this on my current NA OM603 project car.

[Shern]

150psi is pretty high, enough to affect the timing significantly, I’d guess.
What was your reasoning there?

[Screwdriva]

Not sure why they were set noticeably lower at 1550 psi (not by me) or if they had just worn down but Greazzer set them to 1700 psi as part of his rebuild, which I believe is on the higher end of the normal spectrum for a NA engine.

The increase in acceleration is mind boggling for the ol' girl.

[Shern]

Originally Posted by Screwdriva

Not sure why they were set noticeably lower at 1550 psi (not by me) or if they had just worn down but Greazzer set them to 1700 psi as part of his rebuild, which I believe is on the higher end of the normal spectrum for a NA engine.

The increase in acceleration is mind boggling for the ol' girl.

Sorry, got a little confused by your post. 150psi, would mean very little.
I thought you may have been referring to bars, as in, 115 bar for naturally aspirated, vs 135 bar for turbo.

1700 psi makes a bit more sense.

[tdoublenastywitit]

with the money and time we spend wasting trying to make the om617 faster with all the little pump adjustments and upgrades for a minuscule difference is a waste IMO

The only real solution is a super pump

[filp]

Originally Posted by Screwdriva

Not sure why they were set noticeably lower at 1550 psi (not by me) or if they had just worn down but Greazzer set them to 1700 psi as part of his rebuild, which I believe is on the higher end of the normal spectrum for a NA engine.

The increase in acceleration is mind boggling for the ol' girl.

Same story, had all my injectors at 115 bar. Cleaned them, rebalanced at 135 bar for turbo and car seems more lively. The old nozzles still got a nice pattern, and they are Bosch.

[Screwdriva]

Originally Posted by tdoublenastywitit

with the money and time we spend wasting trying to make the om617 faster with all the little pump adjustments and upgrades for a minuscule difference is a waste IMO

You'd be correct if I was trying to achieve more power vs. get my cars to fully renewed, original condition. I set out to achieve this because I believe Mercedes engineers knew what they were doing in the 70's more than they have in any other decade since.

The challenge for folks who think like me is finding the best possible replacement parts available anywhere. This post should highlight why I chose Greazzer's products/ service to achieve this.