Author Topic: AAZ injectors (Read 4649 times)

Benzbeliever · « **on:** February 04, 2008, 08:55:47 pm »

Do all AAZ engines have two stage injectors? Is there an AAZ injector that only has one spring?

Vincent Waldon · « **Reply #1 on:** February 04, 2008, 08:59:02 pm »

Stock is two springs.

Some people retrofit the single stage injectors but the injection lines need to change as well, since the single stage injectors are shorter.

(PFC ?!!!)

Benzbeliever · « **Reply #2 on:** February 04, 2008, 09:23:25 pm »

Thanks.

Why would you want to pull the stock two spring, and go to the single spring?

Vincent Waldon · « **Reply #3 on:** February 04, 2008, 09:39:00 pm »

Quote from: "Benzbeliever"

Thanks.

Why would you want to pull the stock two spring, and go to the single spring?

If you are a tinkering kinda dude... the single spring design is much easier to calibrate, and parts are easier to find.

The dual spring design is mostly about a quieter engine rather than performance... so more pain that it's worth for some. I like a good rattle in the morning. Sounds like......... VICTORY !!! ;-)

Benzbeliever · « **Reply #4 on:** February 04, 2008, 10:00:29 pm »

I'm looking in to them for running WVO. I'm hoping the two stage injector will help the veggie burn more completely :lol:

KAC · « **Reply #5 on:** February 05, 2008, 02:30:31 am »

the same nozzles work for the 1.6 and 1.9 injectors don't they?

commuter boy · « **Reply #6 on:** February 06, 2008, 05:47:05 pm »

Some early AAZ Passats come with single stage injectors. These are the "umwelt" variations, and also have a neutered pump with no LDA and connection to the turbo.

burn_your_money · « **Reply #7 on:** February 06, 2008, 05:53:13 pm »

Quote from: "Vincent Waldon"

The dual spring design is mostly about a quieter engine rather than performance.

Correct me if I'm wrong (which is likely) but doesn't the dual spring make the change in pressure inside the combustion chamber occur over a longer period of time, reducing stress on the engine?

Vincent Waldon · « **Reply #8 on:** February 06, 2008, 09:16:42 pm »

Quote from: "burn_your_money"

Quote from: "Vincent Waldon"

The dual spring design is mostly about a quieter engine rather than performance.

Correct me if I'm wrong (which is likely) but doesn't the dual spring make the change in pressure inside the combustion chamber occur over a longer period of time, reducing stress on the engine?

Nope, as far as I know you are also correct... but I believe they were solving for a quieter engine initially... a small burn to get things started and then the full burn... therefore a less-abrupt "bang" and a quieter engine.

Hence my use of the word "mostly"... as far as I've been able to read the slight reduction in stress is a side effect of trying to reduce noise.

But I've only found one article with a couple of paragraphs on their design... so what the heck do I know ??!!! Perhaps someone else has some better documentation ?

As an aside for us diesel geeks, piezo-driven electronic injectors take this "several burns" concept to a whole new level of course... multiple pre-burns, several main burns, and some post burns as well, different timings and volumes depending on engine parameters etc etc etc. on The 4th edition of the Bosch Diesel Engine Management bible is fascinating bedtime reading !! ;-)

Vince

subsonic · « **Reply #9 on:** February 09, 2008, 10:26:03 am »

I am sending Dave at PP my 1.9 dual stage injectors that have new merc nozzles in them. He is going to run them in his new beast for comparison. If he dyno's them, you will have hard numbers to compare.

MJF · « **Reply #10 on:** February 09, 2008, 02:02:03 pm »

Quote from: "subsonic"

If he dyno's them, you will have hard numbers to compare.

I´d like to see this!

Redrum Rabbit · « **Reply #11 on:** February 09, 2008, 04:16:52 pm »

Will The regular home built pop tester work for these dual spring injectors?

What is involved in shimming them?

commuter boy · « **Reply #12 on:** February 10, 2008, 10:05:05 am »

I suspect there's a mileage improvement on the dual spring injectors.

The umwelt Passat I have gets crappy mileage. Even with the Giles pump with an LDA added and new nozzles, it's still only getting 650-800 kms out of a 70 l tank, about the same as my IDI Golf with a 55 l tank. It's not that much of a bigger car to warrant that difference.

I'm looking around for a dual stage nozzle set to pop in, I'm hoping it will make a noticeable difference.

jtanguay · « **Reply #13 on:** February 10, 2008, 11:09:02 am »

Quote from: "commuter boy"

I suspect there's a mileage improvement on the dual spring injectors.

The umwelt Passat I have gets crappy mileage. Even with the Giles pump with an LDA added and new nozzles, it's still only getting 650-800 kms out of a 70 l tank, about the same as my IDI Golf with a 55 l tank. It's not that much of a bigger car to warrant that difference.

I'm looking around for a dual stage nozzle set to pop in, I'm hoping it will make a noticeable difference.

what is your driving style like?

commuter boy · « **Reply #14 on:** February 11, 2008, 06:39:37 pm »

Not aggressive. My wife gets worse mileage than I do.

Just for giggles I've screwed out the smoke screw, moved the star wheel up and turned the LDA pin to the most conservative setting for this tank of fuel. We'll see how much better it gets. I had a bit of grey haze on heavy acceleration before.