4180C and Ca emissions.

[G50Stang]

Hey guys, new subscriber here. I just bought a 1985 Mustang GT and I am having issues with it passing smog. The car is failing on HC ppm and CO% at 15mph and 25mph. Here are the readings

Reading Limit
HC ppm 425 97 at 15mph
CO% 7.56 .59

HC ppm 432 79 at 25mph
CO% 8.04 .45

I took the 4180c carb apart and the main jets are stamped 279 and the power valve has F2 and 10 stamped on it. Are those the factory size parts? If they are, what other reasons may cause the carb to run rich. As far as I know all the vacuum hoses and egr stuff is on and plugged in. I am running the cats off of my 88 on this car. Any help would be appreciated.

[bob85gt]

hi, what i did was i bought an AFR so i could tune my carb to pass emission. in my state i must run E10 which this car was not designed to run on. with a lot of miles on it i needed to rering the engine (to much oil) and then install new cats to get the car to pass. good luck

[qikgts]

Wish I could help more but I haven't seen those jets mentioned regarding any Mustang carbs. I think there were 622's in the last version of that carb in '85. I also can't recall how the 2 stage PV's were stamped.

What are the "pass" numbers/specs/standards for your car?

In addition to the general rebuild/carb cleaning, make sure that all of air bleeds on the top of the carb are clear all the way through. A paper clip bent straight will do the trick. When I did that to mine I felt the paperclip break through the blockage. Not saying this would fix your issue but it could be a free fix. You could also try to lower the float level in the primary to lean it out some.

FYI, there is really good 4180c info all over this site but you'll have to use google to find it as the forum search isn't so good.

Here is some info about '85 cat's that might be helpful at some point.
http://vb.foureyedpride.com/showthre...-with-an-85-GT

There are also a bunch of threads here about various adventures with CA smog testing. Again, you'll have to find the info using google.

[G50Stang]

Thanks for the info guys. I have a repair kit on order. I'm gonna have to really get into the weeds with this issue. LOL! More to come.

[qikgts]

FYI, the Holley rebuild kit will not come with any jets and will not come with a 2 stage power valve. It will be very difficult to find close limit jets and anything but single stage PV's. Frankly I wouldn't bother looking for either.

Keep us posted on how it goes. Also, welcome to the site!

[xctasy]

Close limit jets exist on many Holley 4180C carbs. They stay in calibration. Anything related to the IM test is most likely gas quality and the need to preheat before testing. CA IM tests can be discussed adequately on Facebook under this group.

I've found it excellent.

Californians for Classic Car Smog Exemptions.

In my opinion, #acebook is resolutely trash, except with groups like this. They posts there problems, and people brainstorm solutions.

On Four Eyed Pride, check with the Carb guys who say California Emissions is broken. Then do what they did, to get there car through the IM tests.

Generally, the
AIR,
EGR,
catalysts
and Hot Idle Correction circuit on the fuel line,
along with the crank pulley elastomeric seal changing the idle degrees,
the variable reluctor in the Duraspark II,
and aspects of the Two Speed Accessory drive, which does funny things to the Barometric Air Pressure sensor to play with timing,
and the passenger side multiple element altitude compensator line, and it's impact on the Emissions Purge for the vapor canister

( see '
http://vb.foureyedpride.com/showthre...nister-missing
' )

You've literally got 93 systems in an 85, and as long as you don't have a hose defect, or a wrong setting, then it's just fuel treatment and catalyst and engine pretreatment by proper heating before testing.

From what I've read, the reason smog techs dislike the carb pre OBDII cars, it's that ,they don't self check with a 25 and 50 thou leak valve on the EGR and AIR and evaporative emissions circuits, and they don't wire 60 cycling items to every fuel flap and sensor and pop out a list of four digit codes like the post 1995 cars do. So if an IM test passes your car, and a roadside smog camera finds the car belching too much Nox, guess who gets there smog records vetted. And carb cars have to present as being genuinely Unmodified, with stock everything. Anything non standard, it's a massive risk to the guy doing the testing.