www.tdiclub.com

Economy - Longevity - Performance
The #1 Source of TDI Information on the Web!
Forums Articles Links Meets
Orders TDI Club Cards TDIFest 2016 Gone, but not forgotten VAG-Com List Unit Conversions TDIClub Chat Thank You




Go Back   TDIClub Forums > VW TDI Discussion Areas > TDI 101

TDI 101 Got a simple/basic TDI question? Are you a newbie (new to the forums). Feel free to post your question here.

Reply
 
Thread Tools
Old July 4th, 2018, 12:04   #1
h.ubk
Veteran Member
 
Join Date: Sep 2016
Location: Idaho
Default Max IQ Value

Hi All,
I just installed rebuilt injectors (stock nozzles). The car seems to have a lot more power but blows coal at WOT. I set injector timing to the top of the graph and when I check IQ it showed originally at 4.4. I bumped it to 5.8 figuring I would need to lower it later, but it is still blowing black smoke.
The prior inectors did not blow coal at all. I have a new OEM head and new OEM turbo on the car. I just cleaned the EGR 5k miles ago. Should I bump up the IQ even more, or should I be looking into something else? My understanding is the more I increase IQ, the less fuel and power and black smoke, but the upper part of the range is 5.
Thanks,
H.ubk
h.ubk is offline   Reply With Quote
Old July 4th, 2018, 13:01   #2
JDSwan87
Black Swamp Thing
 
JDSwan87's Avatar
 
Join Date: Feb 2014
Location: Michigan near Toledo
Default

Quote:
Originally Posted by h.ubk View Post
Hi All,
I just installed rebuilt injectors (stock nozzles). The car seems to have a lot more power but blows coal at WOT. I set injector timing to the top of the graph and when I check IQ it showed originally at 4.4. I bumped it to 5.8 figuring I would need to lower it later, but it is still blowing black smoke.
The prior inectors did not blow coal at all. I have a new OEM head and new OEM turbo on the car. I just cleaned the EGR 5k miles ago. Should I bump up the IQ even more, or should I be looking into something else? My understanding is the more I increase IQ, the less fuel and power and black smoke, but the upper part of the range is 5.
Thanks,
H.ubk
How large of nozzles did you go? You might have to do the hammer mod to get the smoke level down...
__________________

Stella (Mine now): 2005 Shadow Blue Jetta Wagon TDI 09A
Mods: RC1. VCDS HEX-CAN USB (near Toledo, OH)
JDSwan87 is online now   Reply With Quote
Old July 4th, 2018, 13:17   #3
h.ubk
Veteran Member
 
Join Date: Sep 2016
Location: Idaho
Default

The nozzles should be stock. If I do the hammer mod, wouldn't that just increase IQ even more? How high should I go?

H.ubk
h.ubk is offline   Reply With Quote
Old July 4th, 2018, 13:28   #4
JDSwan87
Black Swamp Thing
 
JDSwan87's Avatar
 
Join Date: Feb 2014
Location: Michigan near Toledo
Default

Quote:
Originally Posted by h.ubk View Post
The nozzles should be stock. If I do the hammer mod, wouldn't that just increase IQ even more? How high should I go?
H.ubk
If the nozzles are stock, I suspect you have other issues going on. Boost leaks immediately come to mind. Hammer mod can reduce or increase IQ depending on which way you slide it.
__________________

Stella (Mine now): 2005 Shadow Blue Jetta Wagon TDI 09A
Mods: RC1. VCDS HEX-CAN USB (near Toledo, OH)
JDSwan87 is online now   Reply With Quote
Old July 5th, 2018, 07:43   #5
flee
Veteran Member
 
Join Date: Sep 2011
Location: Chatsworth, CA
Fuel Economy: 40-ish
Default

I would be suspicious of the new settings of pop pressures. Try to get a printout
from whomever did the 'rebuild'. That is assuming they used all original Bosch parts.
What condition led you to get them rebuilt? Have you contacted the rebuilder?
__________________
2002 Jetta GLS TDI wagon, 2012 Audi A3 TDI S-Line
flee is offline   Reply With Quote
Old July 5th, 2018, 09:04   #6
Franko6
 
Join Date: May 2005
Location: Sw Missouri
Default

I say forget the 'printout'. We have never provided any and really, what difference does a print out make if the injectors are blowing coal? Also, of the 'printouts' we have seen, it only guarantees pop pressures, not flow rate. WHAT GOOD ARE INJECTOR SETS THAT DON'T FLOW RATE EQUALLY??

I think maybe I spoke with you before, but the bottom line, if you have the IQ set to 'normal' settings and you are painting the road black out your tail pipe, you have very poorly set injectors. You could have very poor injector nozzles. In any case, a simple check on the VCDS Engine Module/ Block 13 will show nozzles and their compared milligrams per stroke variation. They should read lower than .2mg/str. I'm betting it's not even close...

Setting IQ could be as high as 8.0 or more, but realistically, that would be heroic efforts for poor nozzle calibration.

If it's the same place, doing the same thing, we are looking for the "Baker's Dozen" of destroyed engines from poorly set nozzles over a one year period. When your pistons melt and blow out the exhaust, your happiness fades as fast as your pistons.

One thing I have to say, as this is very typical. We get nozzles back that all that was needed is the piece of dirt removed from the nozzle tip. All lines and the tops of the injectors should be blown out with compressed air before assembly. That could take care of a lot of problems.
__________________
Frank's VW TDI's, LLC
1007 Olive St.
Lockwood, MO 65682
417-232-4634
FranksTDIs@sbcglobal.net

'02 80k grey leather, 99.5 R.I.P 153k
'85A2 NA 375k, '91 A3 290k Always Silver, Always a Jetta
Franko6 is online now   Reply With Quote
Old July 17th, 2018, 22:33   #7
h.ubk
Veteran Member
 
Join Date: Sep 2016
Location: Idaho
Default

Hi Frank,

Thanks for the reply here. I believe I found my problem this morning. One of the pieces that connects to my intercooler is broken in two pieces. I ordered a used replacement from eBay and will install it next week when it arrives. I'll post if I'm still getting any black smoke afterwards.

h.ubk
h.ubk is offline   Reply With Quote
Old July 17th, 2018, 22:37   #8
h.ubk
Veteran Member
 
Join Date: Sep 2016
Location: Idaho
Default

Quote:
What condition led you to get them rebuilt? Have you contacted the rebuilder?
I was getting lots of white smoke upon cold starts on cold mornings. I also believe the fuel economy should have been better. The PO ran vegetable oil and I did not know when the injectors were last worked on (car has almost 400K miles).

Since I have replaced the injectors, the white startup smoke has gone away. I'll post after my intercooler leak gets fixed.

The rebuilder said it was a turbo issue or a boost leak. The turbo is brand new OEM and I installed it about 5K miles ago.

h.ubk
h.ubk is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
ALH with bad fuel economy, IQ set too low? IQ question mrrhtuner VW MKIV-A4 TDIs (VE and PD) 21 April 18th, 2015 19:15
Vag Com max IQ....PP520's installed pfiermka TDI Power Enhancements 6 July 1st, 2008 04:43
Max engine efficiency at max torque... Venturabass TDI Fuel Economy 2 January 11th, 2006 13:30
Playing with IQ for max economy? Toronto_Vento TDI Fuel Economy 1 September 2nd, 2004 19:58
Max Power at 3300 Max Torque 1800 mediko VW MKIV-A4 TDIs (VE and PD) 3 September 28th, 2002 00:54


All times are GMT -7. The time now is 15:18.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright - TDIClub Online LTD - 2017
Contact Us | Privacy Statement | Forum Rules | Disclaimer
TDIClub Online Ltd (TDIClub.com) is not affiliated with the VWoA or VWAG and is supported by contributions from viewers like you.
1996 - 2017, All Rights Reserved
Page generated in 0.13088 seconds with 13 queries
[Output: 87.13 Kb. compressed to 75.36 Kb. by saving 11.77 Kb. (13.51%)]