Just loking at upgrading my injectors to PD 150 ones and wondered if anyone had any experience with doing this and is it worth it.

Been thinking about it for a while and obviously when you remap a Diesel car it adjusts the fuel and power but it isnt te be all and end all! Read below!

If you have a vehicle with a 90hp TDI and 5-speed manual transmission, you have injectors with 0.184mm orifices. If you have a 90hp TDI with automatic transmission in North America, you have injectors with 0.158mm orifices and a higher-pressure injector pump so as to push the same amount of fuel through these smaller injectors (for emissions reasons, at a cost of increased stress on the components and increased engine noise). The European 110hp model has what are known as 0.205mm injectors, and the European "Multivan" 150hp 5-cylinder TDI has what are known as 0.216mm injectors. All of these injectors are dimensionally interchangeable, so it is possible to install injectors one or even two sizes larger in place of the original ones. This will increase fuel delivery without the engine ECU knowing a thing about it, and it will do it without pushing the limits of the injector pump, nor will it extend the duration of the injection period - and not extending the duration is better for smoke, power, exhaust temperature, and efficiency.

This is supposed to be a better thing to do especially if its been remapped already

Just been looking on the net and the 130 and 150 injectors are supposed to be the same!!!

Any feedback?

Edited 12 June, 201115 yr by dannyboy759

Well more fuel equals more smoke, so if it does put more fuel in without increasing the boost a bit it will smoke more.

Not sure on the injector sizes, but personally id look at flow rates rather than out and out sizes.

Well more fuel equals more smoke, so if it does put more fuel in without increasing the boost a bit it will smoke more.

Not sure on the injector sizes, but personally id look at flow rates rather than out and out sizes.

Not strictly true!

More what causes the smoke is the injector opening too long for the stroke to let the extra fuel in

The way to reduce smoke is to use bigger injectors and the extra fuel is injected at the right time when it should be rather than holding the injector open too long

Hense why bigger injectors on a Diesel are a good thing

The injectors on a PD are good for over 250 brake but with lots of smoke and im not sure how that would be on the Diesel smoke test?

And to be honest who wants their car to smoke lots?!

too much smoke and it'd likely fail.

If the map is altered to take into account the larger injectors then fine, but just sticking in larger injectors cant be a good idea?

too much smoke and it'd likely fail.

If the map is altered to take into account the larger injectors then fine, but just sticking in larger injectors cant be a good idea?

Thats the thing it is, people seem to get the wrong idea about diesel injectors where in a petrol you fit larger injectors to deliver more fuel thats not completly the case with diesel ones!

If you put a lot of fuel into a deisel engine via a re map it it not only adds the fuel but extends the time the injector is open to allow that fuel in to the chamber.

Thus its not completly timed right due to the short time the piston is at TDC to compress the fuel hense more smoke!

The advangtage of a larger injector is not only will you get more fuel in, the same fuel as what you had on the last re map but the injector being bigger doesnt not have to over run the TDC of the piston and can deliver the fuel at the correct time thus reducing the smoke.

So in essance its the right thing to do if your going to re map a car, in theory!

But with mild tuinning its not really nessessary as it will increse the smoke within legal limits but you will also get more power, more torque from the same map with larger injectors than the smaller ones and less smoke.

I hope i explained that right? lol

AIUI, what you're saying is correct in principle, with the note that you'll not get a benefit from bigger injectors unless/until you pass the flowrate and degrees/cycle duty cycles of the standard injectors, remembering also that you can run a 100% duty cycle on a diesel without risking lean running like you would be on a petrol.

Yeah fair one, but either way buy uping the fuel to give more power isnt the be all and end all

I mean its not like a petrol where you put fuel in and you put air to match the fual or vice versa

Theres a lot to do with timing on a diesel and increasing the fuel on slightly, ie in my case a re map to about 170 give or take would still benifit from larger injectors!