How to run leaner for emissions test - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Michael Nugent · 11-08-2003, 10:27

Hi all, I need to know a couple of things. How do I tell which model of engine I have? I have a 1983 Econoline van with captains chairs and the foldout bed in back. I just got it and can't tell if it's a 100, 150...

Also, it runs great but fails Washington State emissions (only the idling portion). I put in a new air filter and plugs and used this solution that's supposed to help pass emissions but the retest (after those modifications) tested worse than the original, pre-mod, emissions test.

Thanks very much

-Michael

HandyGuy · 11-08-2003, 16:34

I repaired a guy's 82 Volvo that failed emissions, so we found a Catalytic converter for it fer $75, instead of the dealers' $450.

I cut the rusted old clamps with a sawzall with metal blade,
cause it was frozen, then unclamped the other side and slid out the old CC ......slid back in the new one, and used filler welding rods and oxy acet torch, and a heat shield (12 inch sq piece of sheet steel) to protect thee underside of the body, to fill in the edge gaps where the pipes met.

Then emissions passed with flyin' colors.

'92BigBronco · 11-08-2003, 16:38

Does Washington not have the law that states your vehicle doesn't have to pass emissions if it's 20 years or older?

I'm assuming it has a carb, so try leaning out the idle mixture a tad with the idle air screws.

351w · 11-08-2003, 23:30

i would think that maybe the cat isnt workin as good as it used to or like 92 said try leaning the idle mix.
if you mechanically inclined and you are positive that you have a rich condition you might even be able to get away with changing the main jets to a size smaller.
but i wouldnt go right for that unless you know it is really rich at idle.

'92BigBronco · 11-09-2003, 11:24

The main jets only control the fuel flow when the throttle plate is open.....i.e. pushing on the gas pedal. The idle mixture screws are the only way to adjust the mixture at idle. They normally control the mixture from idle to about 1/4 throttle. Since you're having trouble passing the idle portion of the test, that would be the place to start.

However, I do agree a cat could also help your problem, but it seems to be doing its job at higher rpm so I'd try to pass the test without changing it if possible. Cat's are not cheap.

Michael Nugent · 11-10-2003, 14:00

Luckily I found a guy right next door who told me what type of Econoline and engine I have (Ecololine 250, 351 engine). He tried to talk me into paying him $150 to get it to pass. In Washington your vehicle has to be 25 years old to skip emissions.

I'll try leaning it out a bit. This guy tried to tell me that the high emissions were the result of it running too lean already. From what I know that's a farce. I've rigged carbs before to run nice and lean. I think I can do it again. I had trouble finding the mixture screw at first. Found it finally.

I assume turning the screw IN will lean it, letting the screw OUT with richen it. Anyone know this to be wrong?

Thanks guys.

89F150 · 11-10-2003, 20:35

i dont know squat about carbed engines. I think i need to start learning because my other car needs some work done.

351w · 11-10-2003, 20:45

i know more about carbies than the average joe but i strongly believe in buying a brand new carb when the old one is shot.
yes you can rebuild it and replace all the expendable parts but as the miles add up there are things that you can never repair with a build kit, therefore never get the same performance as a spankin new one fresh outta the box.

'92BigBronco · 11-10-2003, 20:52

Here here! I've rebuilt many a Holley 4 barrel and Quadra-Crap carbs but nothing beats the new Edelbrock carbs for out of the box performance (IMO anyways).

Best of all, no gaskets below the fuel level so it'll never leak.