Nozzle pop and pressure testing

LiquidBlackDZL

Veteran Member
Joined
Feb 19, 2004
Location
SF Bay Area
TDI
2000 Golf
When installing new nozzles onto the injectors, how important is it to pop and pressure test them? Other than being able to verify that the nozzles are functioning, what other benefits are there? Also, if I were to have the nozzles pop and pressure tested, (specifically PP502's on the ALH injectors), what is the recommended pressure?

I talked to a Bosch/diesel service center that said they could install the nozzles and pop test them, as well as set the pressure to whatever the manufacturer recommends, or based on what kind of performance I was looking at getting from them. I didn't know what to tell the guy. He's charging $40 per injector. Would it be worth it?
 

VailPowder

RIP, Gone But Not Forgotten
Joined
Apr 15, 2000
Location
Vail, CO, USA
TDI
2005 Jetta TDI Sedan, 1998 New Beetle TDI, 2004 Jetta TDI
LiquidBlackDZL said:
When installing new nozzles onto the injectors, how important is it to pop and pressure test them? Other than being able to verify that the nozzles are functioning, what other benefits are there? Also, if I were to have the nozzles pop and pressure tested, (specifically PP502's on the ALH injectors), what is the recommended pressure?

I talked to a Bosch/diesel service center that said they could install the nozzles and pop test them, as well as set the pressure to whatever the manufacturer recommends, or based on what kind of performance I was looking at getting from them. I didn't know what to tell the guy. He's charging $40 per injector. Would it be worth it?
I think pop testing is especially worthwhile on the higher performance nozzles... the race 520 series, and PP502 /PP764.

On the PP520, PP357, Sprint 520 they can usually be installed in a normal set of injectors without pop testing ...but pop testing can still be worthwhile.

I think that you will find that $25 / injector is a normal price. And there are a number of good installers who offer pop testing.

We can do pop testing at kermaTDI, or offer exchange injectors when nozzles are purchased.
 

jsrmonster

Veteran Member - TDIClub Enthusiast
Joined
Apr 22, 2002
Location
Red Lion, PA
TDI
15 Golf SW DSG, RC3 piped, 99.5 Jetta Rocket PD150 6spd 4motion, 2000 ASV110 RC6 "Silverbullet" 5spd Race Car, 2003.5 Cummins QCLB 4x4 "Blue Monster" Jeep CRD juiced, MB Sprinter van juiced up
LiquidBlackDZL said:
When installing new nozzles onto the injectors, how important is it to pop and pressure test them? Other than being able to verify that the nozzles are functioning, what other benefits are there? Also, if I were to have the nozzles pop and pressure tested, (specifically PP502's on the ALH injectors), what is the recommended pressure?

I talked to a Bosch/diesel service center that said they could install the nozzles and pop test them, as well as set the pressure to whatever the manufacturer recommends, or based on what kind of performance I was looking at getting from them. I didn't know what to tell the guy. He's charging $40 per injector. Would it be worth it?
Hi,
You can see the balance in field 013 in vagcom. Keep it below +/- 0.5 and it should be ok.

If the bodies are low mileage, its usually not necessary. The real question is what tolerance does the shop (doing the popping) allow. VW allows 5%, but that is roughly 150psi, I like to pop them within 2% or about 3bar-45psi. fyi - I charge $75 to R&R and poptest with chip purchase ($125 w/o tuning). Note: when popping #3, the pop pressure should be slightly lower say 1% due to more inertia from the lift sensor. This is my experience and what the vagcom balance proves too, not written in any books. Don't raise pilot pressures, simply take the highest pressure as the setpoint, and raise the other 3 to match it.

Jeff
 

mrchill

TDIClub Enthusiast, Super Secret Diesel Ninja Vend
Joined
Sep 16, 2003
Location
MASS! home of THE WORLD SERIES CHAMPION RED SOX! x
TDI
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Always test....you are unlikely to have a bad new nozzle....but it is VERYcommon to find a bad...or dirty (rusty or whatever) injector..... I pop test all of them....even when not doing nozzles....If they are out....I test them....
 

jsrmonster

Veteran Member - TDIClub Enthusiast
Joined
Apr 22, 2002
Location
Red Lion, PA
TDI
15 Golf SW DSG, RC3 piped, 99.5 Jetta Rocket PD150 6spd 4motion, 2000 ASV110 RC6 "Silverbullet" 5spd Race Car, 2003.5 Cummins QCLB 4x4 "Blue Monster" Jeep CRD juiced, MB Sprinter van juiced up
Always look at the spray patterns too. I have a handful of brand new bosio nozzles with bad holes or pintles. I use them as bad examples in training and gtgs ;-)

Great demo is to place a plastic bowl under a nozzle and watch it shoot across the table when it pops, cuz one hole is hard stream, and not a nice atomized cone. 5 equally spaced holes should ALWAYS keep the bowl in place when popping!

Some of the nozzles stream at nearly 45deg angle to exit, and others have incorrectly machined pintle lift areas. You can actually swap the pintle between different nozzles, and the errant pilot pressure moves with the pintle from nozzle to nozzle.
Jeff
 

VailPowder

RIP, Gone But Not Forgotten
Joined
Apr 15, 2000
Location
Vail, CO, USA
TDI
2005 Jetta TDI Sedan, 1998 New Beetle TDI, 2004 Jetta TDI
jsrmonster said:
Always look at the spray patterns too. I have a handful of brand new bosio nozzles with bad holes or pintles. I use them as bad examples in training and gtgs ;-)

Great demo is to place a plastic bowl under a nozzle and watch it shoot across the table when it pops, cuz one hole is hard stream, and not a nice atomized cone. 5 equally spaced holes should ALWAYS keep the bowl in place when popping!

Some of the nozzles stream at nearly 45deg angle to exit, and others have incorrectly machined pintle lift areas. You can actually swap the pintle between different nozzles, and the errant pilot pressure moves with the pintle from nozzle to nozzle.
Jeff
If by Pintle you mean the needle .... please do not tell people to swap them. Each needle must stay with the nozzle body as supplied.

Each nozzle and needle are matched on a very expensive computer controlled machine in a batch of 1000. The machining and quality control on Bosio nozzles are extraordinarliy high.
 

scottp

Veteran Member
Joined
May 19, 2008
Location
Windsor, ON
TDI
2010 golf SportWagon (canadian car)
what is the precedure to pop test nozzles. Is it something that can be done at home with some preperation??? Can vag-com tell me if they are 'balanced'? If so what group number? Thanks!!! Sorry if these are stupid questions.
 

LanduytG

Vendor
Joined
Sep 5, 2001
Location
Greenfield, IN
TDI
99 NB 82 Westfalia Diesel
Not uncommon at all to find a bad "new" nozzle. I have done hundreds of injectors and I always feel its good to test them. If you don't you will never know if you have a bad spray pattern or bad nozzles. By the time you find out it could be to late.

Greg
 
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