Can't pass air care, Vancouver Canada, volvo 240 DL 1983.

[sergitin32]

Hi, I have my old Volvo 240 DL 1983, B21A engine, Auto Trans... A beautty, everything to work on it's pretty simple, lets say confy. (even when this thread might look the opposite) I am an amateur mechanic and have done lot's to this car, its so nice to work on these cars its just amazin.

Now eventhough all my work, i can't make it through Air Care, everytime the NOx come high... HATE IT!!!

So i check the book "what if you don't pass" skiping the stealer part... to see the main points I should cover about my fault there are 3 main options:

1- Spark firing timing too advanced... checked, it was advanced, i made it lower, the lowest the posible would be around 5 to 6 degrees in 750 rpm and transmition in neutral. It's there now.

2- The mix is too lean... This i've been fighting with all these past weeks... Haven't check for leaks in the manifolds or the intake side area of the block; but I have done lots of Carbs hours. I have a stromberg 175 cd carb... i dunno if they are hard to adjust, first mine is actually a 175 cd 2-SE, so you cant move the jet form bellow to change the mix but only move the needle so every time have to take the cap off, spring off, take the oil off the little tube inside the piston valve on top and unscrew the little lateral screw holdin the nedle inplace and play with the upper needle regulator bolt... been doing this thousad time at least this past three weeks.

I keep seen one thing, when i go all the way the needle can posibly go down, would be the leanest the posible the mix is, the car starts much more easier... the richer i get then the start is really rough and if too rich well its stalling in the street lights and my wife wants to kill me and suffers in silent by my side blaming us, me and the car for her stressfull pregnancy, lol...

So i keep tunning, but... there is the famous maniouver and I say to my self so many times.: this time it has to come and work that way!
The maniouver is the one you lift the drum or big piston air valve... the big metalic one with the diafragm on top.... so you lift "that" just a gap of 1/16" trough the intake then if the idle doesn't change or let's say it changes a little but then comes back normal thats it, its the right mix!!! greeaaattt i will do it now... but never happens!!! gets me going insane!!! simply every time i do that the car idle goes down... symptom of been too rich... did the same with the old needle, which i broke been stupid... does the same with the new one!!? would the jet had lost tolerance with time and be too wide? My car has only 153000 km on the odometter, the gas mileage is not good, i can say but well i bike more and drive less no prob... its just i can't make that maniouver satisfactorly.

Long story short... Does anyone has any clue who might sale those Colortune spark plugs tools from Gunsons?? I have been dremaing with those but can't find them in BC, Canada... any ideas for some dealer close by in USA???
Any other ideas about my mix carb probs?

3- And finally the EGR system, I think this is the really faulty stuff here, i make my night reading the Haynes about this the other day and there is something i dont get in clear... Does my car supose to have a small switch besides the throttle link, so this activates the vacum amplifier? At the begining with the car there was a big hole in the tube coming from the exhaust to the EGR valve, which i already fixed it, a friend welded another piece of tube to make it work, this piece was a little thinner that the original one but would make the work for a couples of weeks i guess... The rest i haven't check for real... since the checkig started at the micro-switch and i just went there and there is nothing like it, so I fixed the mix (again) so it starts easier and came back home. Any one guys have any clues about how this system works for real? Some advice to spare for me?
In the Haynes manual they keep refering to the Wiring Harness and
micro- switch to check the woltage as a sign of power reaching the vacum amp, and the resistance in the vacum amplifier as some solenoid inside!!!

I can't find the micro switch, but even thou, i cant see any wiring coming from the harness to the vacum amplifier... maybe my model is progressive type, but still has not switch... oh and I can't see any thermostate betwen the vacum amplifier and the EGR valve...
One thing is for sure tomorrow i will tear this system apart and deal with it, but at first sight this blew my mind off... is the car missing somehitngs? or am I... by the way i rebuild the whole Wiring Harness cable by cable and i am sure i didnt miss any... there was nothing like haynes describes in my vehicle...

repeat: B21A engine Canada made Volvo 1983 240 DL.

OH, and a little detail, if any of you guys in any really shitty time and stupiditly working on your carb in the middle of no where, brake your carb's needle... believe me, just put the Valve or Air Piston Valve together, without the needle and just don't cover the carb!!! remove te spring and the cap...
there are two little holes supplying enough air and some fuel for sure, too much!!! coming into the engine from the hole the needle was suppose to adjust into. i made it home like that, just 20 km/h but in a straiht line without the lights could go faster and faster, so, the deal is:
IT DOES RUN WITHOUT A NEEDLE IN DESPERATE TIME!!! way to go.

You guys in this forum doing awsome... thanks for sharing the knowledge!

thanx to you all!
Volvos Rock!