Confused about nozzle sizes

[Rob Mayercik]

Vehicle in question: 2002 Jetta ALH, 01M automatic. Totally stock at 289,986 miles as of today.

A couple years ago I found out that my injectors were out of balance (this was about 60K ago), so had them rebuilt and the nozzles swapped out to Titan .205s, under the impression that this would be a good "mild upgrade" for an otherwise bone-stock car.

Well, not so much - I was "rolling coal" pretty much anytime the engine came off idle. I had the injectors dialed down a couple times and the injection pump "hammer modded" to pull my IQ down, but eventually the vendor swapped me out a different set with slightly smaller nozzles (I never got a definite answer, but it was supposedly somewhere between OEM manual trans nozzles and the .205s) to get rid of the smoking.

After all of that, the heavy smoking was gone, but the MPG never really recovered to what I have historically gotten (usually 42-45 with 75-25 HWY-City mix, got a couple 47s logged in my spreadsheet), and it's been a fight to even make 40MPG now under the same conditions (last two tanks were about 37). Just had the timing belt done at 280K, and at the same time the guy who did it found and installed a couple SW upgrades from VW into the ECU.
It starts very easily (even with the extreme cold NJ's getting) and doesn't smoke, but when cruising at light throttle on the highway I feel it running rough/uneven (to the point where it had me thinking the trans was popping in and out of gear). Put a little load on it and it settles down.

Had the guy who did the timing belt look at it, and he's of the opinion that the trans is fine, and it's either one or more injectors or the "advance" in the pump going. Since it starts so easy, he is leaning toward injectors, so the plan is for me to order up an all-new set, swing by his place for install (with the hours I'm keeping at work, this beats waiting 6 months to find time to DIY it), and then return my old ones for core.

Right now I'm leaning toward the MT injectors this time - I was going to do that originally, but then the vendor recommended the .205s and that didn't turn out too well.

If I understand correctly, the OEM nozzles on my ALH were .158s and the manual ones are .184. Does this sound right?

 

[Seatman]

Bigger injectors alone can hit the mpg a little but a tune really brings them into another place, ups the mpg etc.

 

[Rob Mayercik]

I'm sure it can, but I'm still undecided about doing a tune just yet (the guy who did my last timing belt seems quite taken with the old Van Aaken SmartBox, and keeps telling me I should get my hands on one).

Part of my getting sold on the .205s in the first place was that "they shouldn't impact your MPG any", and I dropped from 43 to 35. I just wanted to do a slight upgrade since my original nozzles were done at that point anyway.

 

[Seatman]

The nozzles were set up and balanced by someone that knows what they were doing?

And yes to the stock ones, that's the sizes

I wouldn't bother with the box, a proper tune or nothing is the only real way to get the best out of these cars, doesn't have to be extreme or anything. Most boxes are just an evry mod where they fool the pump into pumping extra fuel.

 

[FlyTDI Guy]

Vehicle in question: 2002 Jetta ALH, 01M automatic. Totally stock at 289,986 miles as of today.
A couple years ago I found out that my injectors were out of balance (this was about 60K ago), so had them rebuilt and the nozzles swapped out to Titan .205s, under the impression that this would be a good "mild upgrade" for an otherwise bone-stock car.
Well, not so much - I was "rolling coal" pretty much anytime the engine came off idle. I had the injectors dialed down a couple times and the injection pump "hammer modded" to pull my IQ down, but eventually the vendor swapped me out a different set with slightly smaller nozzles (I never got a definite answer, but it was supposedly somewhere between OEM manual trans nozzles and the .205s) to get rid of the smoking.
After all of that, the heavy smoking was gone, but the MPG never really recovered to what I have historically gotten (usually 42-45 with 75-25 HWY-City mix, got a couple 47s logged in my spreadsheet), and it's been a fight to even make 40MPG now under the same conditions (last two tanks were about 37). Just had the timing belt done at 280K, and at the same time the guy who did it found and installed a couple SW upgrades from VW into the ECU.
It starts very easily (even with the extreme cold NJ's getting) and doesn't smoke, but when cruising at light throttle on the highway I feel it running rough/uneven (to the point where it had me thinking the trans was popping in and out of gear). Put a little load on it and it settles down.
Had the guy who did the timing belt look at it, and he's of the opinion that the trans is fine, and it's either one or more injectors or the "advance" in the pump going. Since it starts so easy, he is leaning toward injectors, so the plan is for me to order up an all-new set, swing by his place for install (with the hours I'm keeping at work, this beats waiting 6 months to find time to DIY it), and then return my old ones for core.
Right now I'm leaning toward the MT injectors this time - I was going to do that originally, but then the vendor recommended the .205s and that didn't turn out too well.
If I understand correctly, the OEM nozzles on my ALH were .158s and the manual ones are .184. Does this sound right?

You are correct on your sizes. If you're stumbling at steady cruise state, it could be a few things and injectors are one of them. This would be due more to wear and/or calibration than size however. Some logging of timing, fueling and boost using VCDS would help a lot finding which is the culprit.

 

[memphis tdi]

When I had an auto car, I ran a Van Aaken box with 5 spd nozzles, it was good running combined with the Kerma line pressure mod. & cheaper than a tune.

If you do get a box, look for one that is boost referancing and switchable 100%/off/50%, I had one like this, they can be had for around $150-$175.

However a tune is much smoother and can be tailored to your car/driving habits.

I just sold my Van Aaken box last week and bought a RC2/3 ECU, It is much better running as it increases boost instead of just adding fuel.

 

[30_Yr_Dsl_Veteran]

Well, not so much - I was "rolling coal" pretty much anytime the engine came off idle.

LOL!!! You are a classic example of why the philosophy of "if it ain't broke, don't fix it!" applies!

 

[DanEboy]

It may be the quality of the injectors.
I have Bosio PP520's in my 2000 Jetta auto and I love them.
At first it smoked too much.
But at a get together someone dialed back the fuel via the IQ setting and it's been great since. Only smokes if I punch it. My 50/50 mix of driving before/after has stayed in middle 30's. Best hwy mpg of 49 required driving between 55-60 from Chicago to NY (I broke 800 miles on that tank!).
Kerma has the PP520's
http://www.kermatdi.com/servlet/the-16/PP520%2C-Bosio%2C-Powerplus%2C-nozzles%2C/Detail
But to be conservative and get both mpg and better performance than stock I'd suggest...
http://idparts.com/catalog/product_info.php?cPath=99_185&products_id=617

 

[bbob203]

Your trans could be giving up.

 

[Digital Corpus]

Hammered down the IQ

It still smoked because when you lower the IQ at idle, you increase the fueling, including when at WOT. You smoked still because you increase fueling. IQ should be 3-5 mg/str at the lowest, on average.

 

[LNXGUY]

Lowering IQ = increasing fuel
Raising IQ = lowering fuel.

Silly, but that's the way it works.

 

[Rob Mayercik]

Trans: Hope not, was just rebuilt 2 years/60K ago. My guy says it shifts fine.

(please note: guy who I worked with initially on the injectors is not the same guy I'm using now - the first guy did good work, but was inconveniently distant in terms of getting a ride to/from for pickups/dropoffs. The new guy is just as good, but is only 5 minutes from my house)

Hammer mod was done to put the IQ back into the "normal" spec range. If memory serves, the ECU was pushing its adjustment out to the end of its range (maybe up around 2-2.5) and it was still grossly overfueling. Think it's adjusted to the 6-6.5 range right now, and that was per the injector vendor.

Quality of injectors? Possibly - after a couple "turn down" tries, the vendor lost mine and sent me another set, whose pedigree I'm not sure of. Setup was presumably done by the vendor prior to shipping them to my installer.

 

[kiwibru]

It really sounds like you should invest in a proper "tune" for your ECU. This can make a huge difference in the fueling side of things along with the other tweaks you have done or can do.

 

[Rob Mayercik]

The only "tweak" I've ever done has been to recode the 01M into Sport Mode with the adaptive logic disabled.

Am putting protective film on my headlights tomorrow, then I will have to hunt for my inverter so I can do the logging mentioned earlier in the thread.

 

[Windex]

There are three sizes of Titan nozzles.
Titan 764's - .234
Titan 520's - .216
Titan 502's - .205

Which ones did you get?

You may still be over fuelling. You have an 11mm pump with large nozzles. Without a tune, even an IQ adjustment is going to leave the car overfueled.

Tune Tune Tune.

Then get a tune.

 

[scooperhsd]

I can relate some here -

My Beetle started out with the O1M auto, usually about 38 MPG. 5 speed manual swap at 252,000 miles - MPG jumped up to 46. 297,000 miles - my 11mm fuel pump finally gave up the ghost, and while we were at it, upgraded to PP502s (and dropped about 10% of MPG - currently running about 42) Planning on getting an RC2 tune this summer.

Smoking - well - IF I'm pretty easy on the throttle / keep the clutch fully engaged - it's not too bad. If I get on it / slip the clutch a bit - I smoke like a train (not always a bad thing - great for getting tailgators off my backside ).

 

[memphis tdi]

For a short time, I ran the box with PP520s on my 02 Auto Jetta, I felt like James Bond with the smoke screen I could put out !

 

[FlyTDI Guy]

There's some pretty detailed info regarding injectors and nozzle sizes HERE if you're interested.

 

[Rob Mayercik]

There are three sizes of Titan nozzles.
Titan 764's - .234
Titan 520's - .216
Titan 502's - .205

Which ones did you get?

You may still be over fuelling. You have an 11mm pump with large nozzles. Without a tune, even an IQ adjustment is going to leave the car overfueled.

Tune Tune Tune.

Then get a tune.

I started that little journey with .205s, then had them turned down twice and the IP hammer-modded to get IQ back into what was supposed to be normal range. Eventually I ended up with "mystery nozzles" that were supposed to be slightly above manual ones but smaller than .205 (but the actual size was not specified). no smoke since the mystery nozzles went in, but MPG has been no better than 41 ever since.

Recently I'm feeling what seems like misfires or something at light "throttle", but if I add throttle/load the engine it smooths out. Still trying to find time to get the VCDS onto the system and do the logging requested above.

 

[Rob Mayercik]

Back with an update...

Hey there, everyone. Got an update to share:

A few things (mostly work) slowed me down on getting my issues sorted, but in the past week things have started moving again.

Never had a chance to get VCDS on the car, but did finally got a chance to speak with my mechanic about the injector vendor his friend (who has a nicely modded A3 Jetta) used. I was half afraid he was going to give me the name of the outfit I got the current set from, but he didn't - pointed me at KermaTDI instead.

So I called them up last week to see what they'd recommend for my car, and ended pulling the trigger on a set of Bosio DLC520s (stage 1 setup) through the hot-swap program. Had my guy install and set them up yesterday per the nice pile of info the guy at Kerma provided, and I pick up the car tonight.

According to him, it's running smoother than with the previous injectors, has more power, and no smoke. He also ran it over a stretch of road where he's been able to duplicate my little "stumble", and says that issue is gone now (hallelujah!).

Next step, get a couple days' run on it with my "standard" driving style to see where I stand now on MPGs (once I've characterized that and gotten the cores on their way back to Kerma, it'll be time to try out the extra ponies and have a little fun ).

 

[Digital Corpus]

See emphasis

...Bosio DLC520s (stage 1 setup)...

Why did you choose to have this done, which is a hardware modification to the nozzle, instead of hammer modding the IP and/or getting a tune? Your nozzles will not flow fully unless you have them taken out and modified again.

 

[Rob Mayercik]

See emphasis
Why did you choose to have this done, which is a hardware modification to the nozzle, instead of hammer modding the IP and/or getting a tune? Your nozzles will not flow fully unless you have them taken out and modified again.

I'm sorry, I have no idea what you're talking about.

Per the Kerma site, "stage 1" is for " Low Smoke for cleanest operation [ ideal for stock or lightly modified vehicles, or for modified vehicles seeking best fuel economy ]". This was a hot swap of assembled bodies/injectors to try and correct what was identified to me as a drivability problem caused by misfiring/leaking injectors. All the other stages sounded like they were unsuitable for a stock motor.

A hammer mod was done a couple years ago per the "Brand X" nozzle vendor, to put the IQ into the 6.0-6.5 range (after "turning down the injectors" a couple times). As far as I know, that has never been undone.

Can you restate your question? Maybe a different wording will click better for me.

 

[vanbcguy]

The KermaTDI "stages" involve modifying the nozzle to reduce its flow. So what you bought was a nozzle that has been modified to reduce its total needle lift in order to reduce the fuel output of the nozzle versus what it would be stock.

Sent from my HTC One XL using Tapatalk

 

[Rob Mayercik]

The KermaTDI "stages" involve modifying the nozzle to reduce its flow. So what you bought was a nozzle that has been modified to reduce its total needle lift in order to reduce the fuel output of the nozzle versus what it would be stock.

Sent from my HTC One XL using Tapatalk

That's much clearer, thanks.

And that's what I wanted - the car's completely stock otherwise, so I don't need full flow on something that big.

 

[Drivbiwire]

The KermaTDI "stages" involve modifying the nozzle to reduce its flow. So what you bought was a nozzle that has been modified to reduce its total needle lift in order to reduce the fuel output of the nozzle versus what it would be stock.

Sent from my HTC One XL using Tapatalk

Stop right there....

NO MODIFICATION IS MADE TO ANY NOZZLE IN ANY WAY!

DO NOT UNDER ANY CIRCUMSTANCE MODIFY OR MANIPULATE ANY NOZZLE IN ANY FASHION OR YOU WILL RENDER IT UNSERVICEABLE!

Put that Internet BS to bed once and for all and STOP spreading that information on the internet.

If you don't have the equipment to measure nozzle flow volume using precise flow curves YOU CANNOT set flows or adjust them. There are multiple adjustments that are done to the injector for either flow, ejection, dispersion, sequencing and a few others which must be taken into account when overhauling an injector and the unique characteristics of the specific nozzle being installed.

Also DO NOT attempt to relap ANY component of the injector! Using lapping paper will curl the edges and create waves of distortion on the faces. I have had do A LOT of lapping lately because of people reading this on this website and nearly ruining good injector nozzle holders.

Pete
DBW LLC
www.DBWLLC.net

 

[Rob Mayercik]

Ok, so that wasn't a good "translation" of what Digital Corpus said, I guess.

Whatever. Everything pointed at Stage 1 being the best suited to a stock engine, so that's what I picked.

 

[vanbcguy]

Stop right there....
NO MODIFICATION IS MADE TO ANY NOZZLE IN ANY WAY!
DO NOT UNDER ANY CIRCUMSTANCE MODIFY OR MANIPULATE ANY NOZZLE IN ANY FASHION OR YOU WILL RENDER IT UNSERVICEABLE!
Put that Internet BS to bed once and for all and STOP spreading that information on the internet.
If you don't have the equipment to measure nozzle flow volume using precise flow curves YOU CANNOT set flows or adjust them. There are multiple adjustments that are done to the injector for either flow, ejection, dispersion, sequencing and a few others which must be taken into account when overhauling an injector and the unique characteristics of the specific nozzle being installed.
Also DO NOT attempt to relap ANY component of the injector! Using lapping paper will curl the edges and create waves of distortion on the faces. I have had do A LOT of lapping lately because of people reading this on this website and nearly ruining good injector nozzle holders.
Pete
DBW LLC
www.DBWLLC.net

I don't get what you are saying... Are you saying that KermaTDI's various 'stages' for their nozzles is not actually a modification of the nozzle, and that they are doing something else to provide multiple different flow rates for the same nozzle? Or are you just saying that it's a bad idea?

I don't think anyone was in any way suggesting that it was a good idea to modify your own nozzles.

 

[Digital Corpus]

Honestly, I don't know/understand the specifics of why the nozzles flow less, but the translation's point by vanbcguy is still the same: the nozzles you bought were physically modified to flow less than what they were designed to flow.

This is a new thing a couple vendors started doing about a year and a half ago the clouds the market for new members to this community. Yes, the benefit is that your cost is less for a single purchase, but it also means that you're buying a product with an intentional, physical limitation to it. The proper way to tend to over fueling is through a tune, i.e. having the ECU control injection quantity.

It's like buying a really bright spot light and thinking it's too bright for your uses, you paint over the front lens to make it dimmer instead of turning down the current in the power supply to it. The only different is that the paint is easily removable, but the modification to the nozzle is not.

 

[Digital Corpus]

I don't get what you are saying... Are you saying that KermaTDI's various 'stages' for their nozzles is not actually a modification of the nozzle, and that they are doing something else to provide multiple different flow rates for the same nozzle? Or are you just saying that it's a bad idea?
I don't think anyone was in any way suggesting that it was a good idea to modify your own nozzles.

Keep in min DBW does sell his own nozzles in the staged configurations too.

 

[Abacus]

Umm, DBW does Kerma's nozzles.

Welcome back Pete.

Pete, I think you are confused as to what vanbcguy posted. He did not mention anyone modifying the nozzle in any way, just that the 'Stages' are simply reduced flow that YOU (Pete, DBW) set the injectors at so they'll flow less out of the same nozzle. He did not advocate anyone else doing it, like you referenced.

Please go back and read what was posted and it'll make sense. No need to go off half-cocked by skimming the posts.