More smoke with PW injectors installed

[rdodd]

Yesterday i insalled PW injectors in my 92 DC and it made a very noticable difference in power and acceleration. Boost went from 20# to 26#. Pyro temps didn't seem to change much but i haven't towed yet. Throttle pedal seems much more touchy. Now if i quickly hammer throttle i notice a big belching of black smoke for a second and then it goes away when boost comes up. Iam running 16 cm housing and would like to keep it. Does this sudden belching of black smoke hurt anything or should i back off on diafram adj?It was set up a little to improve response when i had stock injectors. If i back off on this adj. will i get more turbo lag?

 

[rdodd]

I read boost gage wrong when i posted boost went from 20# to 26# after installing pw injectors. Boost went from 20# to 24# after inj. change. My isspro gage has the 25 # mark sitting beside the 23# mark and this threw me off until i examined gage more closley. rdodd.

 

[R.E. Miller]

As long as you're not exceeding 1300 on your pyro, you should not be hurting anything but the finish on the surrounding vehicles and your fuel economy. I am not that familiar with the diaphram adjustments yet... . any one else here?

Russell

 

[paccool]

If the pyro probe is located after the turbo, I wouldn't go to 1300 degrees. They say there is a difference of 100 or 200 degrees before and after turbo. (can't remenber the exact number)I try to keep mine below 1100 degrees as my probe is after the turbo.



My 93 smoked a lot more with the PW injectors. Before they were installed, the pump was turned up just a little. Not long after the injectors were installed, the pump failed. Didn't have anything to do with them but turning up the pump probably influenced the problem just a tad!



Since then I had the engine timing pin set, (it was 2. 5 degrees off) and the pump timing set at 1. 7 . Had to turn the pump down some due to smoke and it still smokes when I get on it. I was thinking of turning it down some more but decided to get the turbo housing changed first and then see what the smoke is like. If you want turn it back a little, mark every thing before you move it. Then you can go back to where you were. Play with it a little.



The smoke isn't always bad though. The other day a low rider pickup pulled up on my right side at a light with the music a little loud. Was sitting right at the back bumper. That "puff of smoke" you were talking about is real heavy on my truck untill the boost comes up. Anyway, as I took off real hard I saw him swerve to the right to get away from the cloud. Was a white truck and I guess he was afraid to get it dirty! Oh, the joys of a diesel!

 

[BushWakr - RIP]

A rough rule of thumb for the post-turbo pyro mounting is 10*F for every 1 lb. of boost.

eg: 20 pounds boost X 10*F = 200*F over pyro reading.

Again, thats if the temp. probe is mounted after the turbo, in the radius portion of the downpipe elbow. Also I think that the further along that radius you go the more you may need to "compensate" your estimate.

There are some really great threads on adjusting the AFC/star-wheel to control smoke on this site. Search through them and don't forget 'the archives'.



Regards, Bob