Select your language

Die Bosch D-Jetronic war 1967 die erste Großserien elektronische Einspritzung der Welt. - Bosch's D-Jetronic was the first mass-production electronic fuel injection.

Can D-jet handle a bored engine?

  • pietercc@gmail.com
  • Topic Author
  • Offline
  • New Member
  • New Member
More
24 Aug 2025 23:05 #23855 by pietercc@gmail.com
Can D-jet handle a bored engine? was created by pietercc@gmail.com
I plan on increasing the displacement of my volvo 164 by .15L by boring the block out to use different piston, something very common in the volvo 140, would D-jet be able to handle that much of am increase? Should I get 5% larger injectors? It doesn't seem like much, but I am unfamiliar enough with the system, that I want to check.

-Pieter

Please Log in or Create an account to join the conversation.

  • nordfisch
  • Away
  • Platinum Member
  • Platinum Member
More
24 Aug 2025 23:42 - 24 Aug 2025 23:43 #23856 by nordfisch
Replied by nordfisch on topic Can D-jet handle a bored engine?
Hi Pieter,
the D-Jetronic is actually a closed system and precisely matched to the series engines.
Changes to the engine require changes to the D-Jetronic, and these are always experimental.

You won't find any higher flow injectors. The original ones have a certain tolerance - but if someone would select them, they would be extremely expensive. Other injectors do not fit the system and the China productions are unusable.

However, a 10% increase in fuel pressure would provide the 5% flow you need.
That's the way I'd go.

We have several Opel-users here who have changed the block from 2800 to 3000 cc - and it works without probs.
But if a modified camshaft is added, you need your own, very individual setup, which is associated with Dyno work and so on.

Regards
Norbert
Last edit: 24 Aug 2025 23:43 by nordfisch.

Please Log in or Create an account to join the conversation.

  • Dr-DJet
  • Offline
  • Moderator
  • Moderator
  • Dr-DJet repariert und sammelt alles! :-)
More
25 Aug 2025 06:50 #23857 by Dr-DJet
Replied by Dr-DJet on topic Can D-jet handle a bored engine?
Hi,

D-Jetronic is a rpm and load controlled system. rpm is main input. In each ECU a curve for volumetric efficiency of engine is hard code. When you change bore or manifold of an engine, you change this curve and ECU will not know. Secondly you might change load curve as well which is measured via MAP sensor.

So clear answer is that it will not work properly. You would need an engine test stand to measure new curves and modify hardware of ECU and MAP sensor to make it work properly. So if you do your plan, you are on your own experimenting test field.

Viele Schraubergrüße - best regards, Dr-DJet Volker
Alles für den Mercedes-Benz R/C 107 und W116 in der SLpedia Sternzeit 107
Workshops D-Jetronic 20.9.(ER)

This image is hidden for guests.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

Time to create page: 0.094 seconds
Powered by Kunena Forum