nozzle questions on 2003 A4 ALH

I have a 2003 A4 ALH engine TDI with about 130K miles on it. Usually got 44-47mpg until about 6 months ago. I had cleaned the intake manifold for the 2nd time around that time. The fuel mileage dropped to about 39mpg around that time. Of course I changed jobs and no longer do long highway drives. Nearly all city driving. I took a day trip recently and got about 45mpg on interstate. But I need to get a check engine light looked at (i blocked off the exhaust gas cooler and took care of the EGR valve). While I'm doing this at a trusted mechanic, I thought I'd get the injector nozzles replaced.

Maybe I don't need to get the nozzles replaced. I've read on here of people who insisted they really ought to be replaced at a little over 100K miles, others say they have the originals at over 200K. I did a search on nozzle upgrades.

Options:
1.The Kerma Powerplus 520 have +20HP and run $357. A fee of $357 to balance injectors. I'm going to subject myself to ridicule, but if something comes this highly recommended and is "so much better than stock" with closer tolerances in their manufacture, why would it need to be rechecked/rebalanced? Sounds more like having a vehicle scotchgarded when you buy one. I know, I'm old (way over 30) and I bought cases of ammo in the early 80s when it was feared that the russians would attack. Had to buy 'Mercun-made' ammo by remington but I've come to find that the chinese stuff makes jackrabbits explode just as good (had to use it for something, the russians didn't make it over. Not yet). There is a local shop here that will pop test your injectors for free.

2.Bosio Sprint 520 for $199 from TDI Parts (who I've used before). I think these have a +20HP upgrade, but correct me if I'm wrong.

What I'd REALLY like to know is, will the fuel economy stay the same or better, or do I have to worry that it might go down? The way I understand it, unless you really stand on it, it's not going to go down, but might actually improve.

thanks,

westerntexan

PP520s are nice. Franko6 has a program to send you new balanced injectors with tips and you send him your old ones after the swap. No down time, can't beat it.

FE is about the same plus more fun factor. It might improve a little after a good quality tune, but nozzles are about a wash on FE IMO.

They do clog and wear sitting down inside of the head subject to millions of compression strokes. I don't think you NEED them if the car is running smooth and not smokey, but it doesn't hurt anything.

I put Sprint 520'2 in mine at about where your mileage and I could not believe the difference. It took about 2 hours to rebuild the old ones with the new ones and purge the injectors after install and took her for a spin. WOW

Im sure the PP520 are close to comparison for power.

Not to hijack your thread, but when you clean the intake manifold, did you have the egr disabled before and the CCV Mod? If so, I thought this would take care of the gunk buildup in the manifold.

PP520's are a great upgrade, even for stock. I got them originally for the extra "passing power" knowing that they do well with a tune and even a bigger turbo down the road. As far as fuel economy I didn't see a huge difference with just the nozzles when driven sanely, leaving me with 45-47 mpg constantly.

If it were me, and I saw a drop in my fuel economy, I would hold off on any upgrades until I found the source of the mpg drop. You should get a few more tank full's of mpg calculations to verify that you don't have an underlying issue. If your intentions are to improve your fuel economy with nozzles, you might not get your money back at the pump with the improved fuel economy, but it's still a fun upgrade. then a chip, clutch, turbo.....

Chip is next for me! I can't wait to have 2 maps to switch from Economy Mode to Performance Mode! Then get a turbo down the road. I do mods at a slow process....Need more $$$

i recently put sprint 520's in my 02 jetta and saw a 5mpg drop with normal driving. Not sure if something is wrong but I did not expect that kind of drop. I'm gonna try to look into it and see what could be causing it.

At 67K miles, I cleaned the intake manifold and put it back together the way it was. At about 120K, I blocked off the exhaust gas cooler and took care of the EGR. I don't think it's a gunked up intake. I'm thinking more gunked up injector nozzles.

I think it's a combination of the different type of driving I'm doing now; almost exclusively stop 'n go in city driving, combined with gunked tips. Despite what a lot of people say "doesn't make any difference whether I'm pulling a gooseneck (diesel pickups), driving 80mph, or sitting still taking a nap for 2 hours at a roadside park while idling then starting up and driving again; I CONSISTENTLY get X miles per gallon". I really do believe it depends on how you drive.

Thanks for suggestions, I'm just so preoccupied with other things right now that I'm considering having it done by someone else just in case something goes wrong. If I had time to leave it apart or haul it in if something did go wrong, I'd probably do it myself and just try to clean the tips it has. But if I'm going to pay someone, I'll probably go with the $200 tips and have them done by a trusted mechanic.

thanks again,

westerntexan

You wont be disappointed that's for sure! Keep us updated!

CSM Jetta said:

i recently put sprint 520's in my 02 jetta and saw a 5mpg drop with normal driving. Not sure if something is wrong but I did not expect that kind of drop. I'm gonna try to look into it and see what could be causing it.

Click to expand...

Did you just "put them in" or did you have a qualified shop balance/flow test them, otherwise you don't know if its the nozzles or the injectors that are the issue. You need to hook up the VagCom and check the idle balance first, now that they are already installed.
My MPG went up a little w/Sprint 520s and the power increase was very nice. Mileage will NOT go up if it's not driven the same, which can be difficult w/extra power.
There is no reason the MPGs should go down that much (5mpg) unless you're still exploring the go pedal or else the injector/nozzle install is poorly matched.

Exactly what Jettawreck said. It takes alot to drive slow again after putting them in, so MPG will suck until you drive it the way you used to drive.

My record 55MPG was on the OEM nozzles, but then again, I have not challenged these new nozzles for highest MPG driving. But I will this weekend, driving 900 miles! Will report what I get. Clean oil, filter, new Caterpillar fuel filter, fresh tire rotation w/45PSI all around! I'm ready!

But I have reached 49MPG so far on the Sprints!

When I get back, changing out my Manual Tranny Fluid to Lubro Moly Fully Synthetic Gear Oil GL5 SAE 75W-90! Might make a difference too! WIll check MPG before and after.

Recently had PP520's installed (TDIParts) in 02 jetta 193,xxx mi. Regained the 2k-3k rpm zippp that had been missing for a while. Also saw a slight inprovement in mpg. The original injectors will last/function a long long time with diminishing results. I looked at both Sprints and PP's and I am very pleased with my choice. Go for it. You will not be disapointed.

At the GTG in Milwaukee on Saturday, I watch Frank Irving testing injectors and installing new nozzles. After watching the work he did on one member's injectors, I had the notion to let him check out mine. What I was running were Bosio PP520 nozzles with about 100k miles on them -- they seemed perfectly fine and I had no idea that they were in less than satisfactory condition. My main concern was that when they were installed, that was all that had been done... no pop-testing, no flow-testing.

What I observed was that my nozzles were really in poor shape, probably good for a little longer but at some point they might have failed and caused real engine damage. All four pop-tested weakly, I do not know how bad that is. But the spray patterns were not good -- instead of five nozzles spraying down in a cone pattern, one had only three nozzles spraying and they aimed straight out to strike the cylinder walls. So there was poor combustion in that cylinder, and the others were only slightly better.

As a result of this observation, I asked for new Bosio PP520s, and that is the beginning of the second part of this story.

Frank has been arguing for many months that Bosio nozzles are not all the same, that if you buy a box of four nozzles they will not be identical. In my case, he only had to test 6 nozzles to find 4 that were almost perfectly identical. The other two were significantly different, enough that it might have affected the drivability. After these were installed, when the flow was tested with VAG-COM, the differences between injectors was only +/- 0.19 -- normal is somewhere between +/-0.50 and +/- 1.0 (I do not remember what is the unit of measurement, maybe grams per injection cycle?).

My point is that even the best nozzles --- and I am still convinced that Bosios are excellent nozzles -- even the best ones will not last forever. And even the best need to be professionally mounted on the injectors, and preferably by someone who can substitute nozzles from other packages to get four that have identical flow rates, etc.

Yes, I have learned some new things from talking with Frank also. My Sprint 520s were just pop tested (local Bosch injection shop) and installed (by me) a year and a half ago. Didn't know any better. Car certainly runs better/stronger than w/original nozzles, and mileage went up. Overall very happy. But, after looking at block 13 w/VCDS, there are some variables between cylinders. Perhaps it can/should be better.
Frank is rebuilding the head for the project car and setting up a set of Sprint 520 injectors/nozzles for it, which he suggested I install in the current car and see if there is a difference. He says there will be, so I will find out with the swap. Should be interesting, but I need to get my intake cleaned and try the "chemical" VNT cleaning done before good and fair comparisons can be made.

jettawreck said:

Did you just "put them in" or did you have a qualified shop balance/flow test them, otherwise you don't know if its the nozzles or the injectors that are the issue. You need to hook up the VagCom and check the idle balance first, now that they are already installed.
My MPG went up a little w/Sprint 520s and the power increase was very nice. Mileage will NOT go up if it's not driven the same, which can be difficult w/extra power.
There is no reason the MPGs should go down that much (5mpg) unless you're still exploring the go pedal or else the injector/nozzle install is poorly matched.

Click to expand...

Well I filled up again today and recorded 31mpg. That was with about 7/8 of a tank of conservative driving and a few small bursts of power over the last 1/8 tank.

I installed them myself and it was a PITA because of how much trouble to get it started again. I was considering sending them off to Frank06 but that would require switching them out again and I do not want to mess with getting it started again. Are there local places that can pop test and flow test them? The idle balance was good as I was told. That's about a 9mpg drop from my usual 39-40 mpg in town. This is unacceptable I think but I really don't want to spend hundreds more dollars on having my nozzles taken out and replaced again.

Any suggestions? Are my nozzles bad or are there any suggestions of any chain shops that can pop test and test the flow of my nozzles to hopefully improve my mileage?

BTW I'm in Chapel Hill, NC if anyone knows of a local place.

Thanks

Are the injectors balanced? You can see that through vagcom. Still doesn't tell you if one was bad spray though.

Not sure. I'll go check sometime this coming week and let you guys know.

Is there any sort of place that can see the spray pattern etc? Like a diesel shop or something?

A diesel shop can pop test them to check spray pattern.

westerntexan, you might want to run a can of diesel purge through the car before you swap nozzles and see if your fuel economy improves. If your car is a manual you should be getting 42-44 even in suburban/urban driving. If it's an auto maybe the mileage number is OK, but you probably also don't want to go as big as PP520s with an auto. PP357s are usually a better choice.

Frank does excellent work, and he really saved a member's car last Saturday. I was very impressed. However, I've also installed a lot of nozzles on injector bodies in the past few months and have pop tested them all. So far they've all tested fine without shimming. My point is if your injector bodies are in good shape, a simple install and pop-test may work fine.

Just got back from my trip and tested the 520's and I got 51.14 with 10-15MPH side/head wind! I still think I can hit 55 with them though on a good day and pumping tires up to 45 instead of 40.

Never had a Diesel Purge yet, how does that work and what does it do? Is it like adding Sea Foam to gas engine?