TD25 v TD27 injectors

[itiejim]

I recently put a TD27 from a 2003 Terrano into my 1999 D22 in place of the original TD25. I used the original manual Zexel pump, which I had professionally rebuilt whilst it was out.

I'm not entirely happy with the fuelling - too smokey off boost when you put your foot down - so I thought it a good idea to swap in the original injectors from the TD25 as they are set up for the pump. On removing them though, they are a smaller diameter and thread from the Terrano ones.
The Terrano ones are Bosch KCA17S42 130 bar, but the ones put of the TD25 are only marked 0050T on one side and 963 on the other. Can anyone say what pressure they should be or what I can do to get the correct pressure injectors I need?

 

[tweak'e]

it pays to mention that you have a TD27T, helps to know you have the turbo version.

when playing with fueling, always have an EGT gauged installed. high EGT in off boost will show thats its over fueling.

i suspect the pump reco guy wound up the fueling to make it suitable for the bigger motor.
simple fix is to turn down the fueling (and you may need to readjust timing as it will retard a bit when you adjust it).
if under boost egt's are fine, a better way is to tune the boost compensator so it limits off boost fueling a bit more. some have adjustable boost pins.

changing injectors will just cause bigger problems.

 

[itiejim]

Thanks for the info. I can confirm that, although I told the recon place that I was using it on a TD27 he set it as per the original TD25.
I have fitted an EGT sensor, but need to wire it in. By the sounds of it, that's the next job.

My concern with the injectors is that the increased pop off pressure is effectively retarding the injection. I'm inclined to leave the fuelling as it is (on boost there's no smoke), advance the timing slightly and see what the EGTs do. Any thoughts?

 

[tweak'e]

do you have a gauge to set the timing?
you could advance it a bit, the noise will soon tell you if your to far advanced.

 

[itiejim]

I have a couple of dial gauges for machining work, but I'd need to rig something up to get them to read. Aside from that I'm guessing there won't be any data for this combination of engine, pump and injectors as they aren't meant to be together. Given I only ever set it by eye I'll mark the position and try tweaking it.

 

[tweak'e]

you need the adaptor for the dial gauge.
if its eye baled then i suspect its retarded a fair bit.