Do Large injectors mean diesel smell

[powermandan]

I have an AFN currently with china special 0.300 nozzles set at 270 bar by an injector specialist.

The project has been on and off for years. So difficult to accurately describe a time line. I previously had 0.260 injectors by Gibonta. I vaguely recall there was a smell at idle.


But these 0.300 are ridiculous. I can idle on my drive as it fills my house full of smog.... I did adjust SOI as a test at one point and it made no difference


I am pondering buying 0.280 Gibonta nozzles from dark side.

However I am conserned that it will be a waste of money.

Does large nozzles just go hand in hand with idle fumes? Or have I just got cheap nozzles and things can be improved .

Opinions please?

Thanks

Dan

 

[adamss24]

Basically with large nozzles you get bad atomisation you can either get a larger pump head and aggressive camplate and a lift pump to ease the pumps job !

 

[burpod]

i've done quite a few big nozzle installs (.260s from powertdi). i don't find there is excessive smoke at idle. most cars i've worked on have no cat however, and do smell a little bit more at idle than a stock car but it might just be from having no cat. and at least when warm, no visible smoke. 11mm/.260s runs very well IMO. if all is good with the tune/car, no smoke unless trying to push more fuel than the turbo can safely boost....

 

[powermandan]

I already have the original MK4 Auto 11mm pump. Which from memory was the most desirable cam plate.

Turns out I actually got 0.320 fitted after checking my records.. So perhaps it's just the nozzle size not the nozzle quality.

I wish quality nozzles were cheaper, then it would be a no brainer and just the get the 0.280s

 

[PakProtector]

Be glad you're not playing with injectors for a PD car...

Douglas

 

[powermandan]

Would anybody care to share a video of there exhaust at idle running .280+ nozzles at idle. Preferably on a Bosch VP based vehicle

Would really help me out.

 

[garciapiano]

I’m pretty sure diesel means diesel smell.

 

[burpod]

i never took any videos, but ALHs i've worked on with 11mm .260s from powertdi and no cat, for the most part, have no visible smoke at idle. smells pretty normal for a cat-less. it could be the nozzles, pump, or it could just be the tuning as well to some degree??

 

[garciapiano]

If you have visible smoke at idle, that's no bueno. I only get a touch of gray smoke on cold mornings on cold starts... once the car is warmed up, no smoke at idle at all. Sort of depends on your fuel too.

 

[powermandan]

If you have visible smoke at idle, that's no bueno. I only get a touch of gray smoke on cold mornings on cold starts... once the car is warmed up, no smoke at idle at all. Sort of depends on your fuel too.

What size injectors and pump do you have?

 

[[486]]

large injectors just don't burn fuel good at low engine speed at all
you will get a lot of fuel in your oil if you idle much
white smoke pretty much can't be fixed once you have enough injector to make decent power

you can bandaid it somewhat with a 12mm pump head (I can confirm it lives to 6k rpm and 5v QA with chinese .30 nozzles and de110 camplate, cummins application return springs)
but it will always be a very poor fit for city driving (unless you enjoy being a nuisance)

 

[[486]]

I have long had thoughts about putting a tdi pump onto an IDI head to solve the injector size issues
IDI injectors flow all of the fuel, and with an electronic governor you should be able to get it to live at high power output
needle lift sensor I was going to try the piezo sensor from an international 7.3 IDI, but another option could be a single combustion pressure sensing glow plug stuck into #3

 

[burpod]

not sure where you get that. i've tested and driven numerous 11m/.260s... aside from some issues with some cars at low coolant temps, once it's warmed up a hair, it doesn't smell or have any smoke.. no more than any other tdi compared to those with cat or not cat. no cat will always smell a bit more. at least based on smell and visual test, the difference is negligible

 

[dieseldonato]

.260/11mm combo other then normal puff at start up, and on cold days it smokes bit ill it gets a little heat in it, doesn't smell different then any of my other diesels I have.

 

[WarmStart]

I have long had thoughts about putting a tdi pump onto an IDI head to solve the injector size issues
IDI injectors flow all of the fuel, and with an electronic governor you should be able to get it to live at high power output
needle lift sensor I was going to try the piezo sensor from an international 7.3 IDI, but another option could be a single combustion pressure sensing glow plug stuck into #3

You can use BMW 2.5tds injectors (there are other engines to...)
Wag IDI engine head doesn't handle extra heat from the fuel, BMW and MB are made from better materials.
We have drive here on the icetrack with diesel long time, MTDI is the best choice.

 

[adamss24]

not sure where you get that. i've tested and driven numerous 11m/.260s... aside from some issues with some cars at low coolant temps, once it's warmed up a hair, it doesn't smell or have any smoke.. no more than any other tdi compared to those with cat or not cat. no cat will always smell a bit more. at least based on smell and visual test, the difference is negligible

He is using 0.300 nozzles of questionable origin. Many have reported similar poor atomization with some large VEP nozzles, perhaps it’s poor quality control, lower pump pressures or bad mapping...or a combination of all three ! I have 0.260/12mm pump and hybrid turbo on a golf mk2 AHH/ALH engine combo, I am using a mix and match of pistons, twin valve springs and lowered compression ratio- the car smokes minimal on idle but does puff a little on a drive over 3500 rpms ! Tuning is not finished as I am stuck with doing welding and spraying before I get it back on the road.

 

[powermandan]

Just to be clear.

I am only really concerned about idle.

The pump has just come back from Bosch specialist for a service and test. So you would have to assume that it is within specification.

I experimented with SOI at idle range, to which there is no affect on fumes.

I cant really think of any other aspect of tune that would affect fume production at idle. Although I am happy to try any well reasoned idea.

I run a 2.5 exhaust system, No Cat. So perhaps that is contributing

The van is in bits currently. I will post a video when it's back together. I will make sure I do it when cold and warmed. I can't really think of a time when I have fully warmed it up and observed the emissions at idle. Mainly because I don't want to smoke my house out.

 

[[486]]

not sure where you get that. i've tested and driven numerous 11m/.260s... aside from some issues with some cars at low coolant temps, once it's warmed up a hair, it doesn't smell or have any smoke.. no more than any other tdi compared to those with cat or not cat. no cat will always smell a bit more. at least based on smell and visual test, the difference is negligible

260s aren't big enough, they run clean (lean out) on the top end
tbf, dss 360s are too small for the same reason too

 

[[486]]

Just to be clear.

I am only really concerned about idle.

stock nozzles

 

[dieseldonato]

Did you decompress the engine at all? That doesn't help idle hazing if you did

 

[powermandan]

.320 nozzles, 11mm pump, Cold idle

youtube.com

Here is the video of it idling cold.

Stock compression ratio

 

[dieseldonato]

Well, ylu won't have any mosquito problems.... but in all fairness it's most likely an injector issue, not atomizing the fuel properly and or not the right angle spray pattern for the piston bowls.