1987 Mazda b 2000 emissions

I can’t pass emissions because the truck always runs rich. What is causing this? It has 187000 miles on it and we can’t find the problem. Please, can any body help?!!! The carb has been rebuilt.

@cdaquila can we edit his title so his email address isn’t displayed? Also can we move this from Ask Someone Who Owns One into Repair so we can give this poor guy some help (for some reason, the “Ask Someone Who Owns One” category always disappears after I’m done reading them even though I have all categories selected to be shown).

OP What kind of truck are we looking at? What year?

Sorry. It’s a 1987 Mazda b 2000

1987 mazda B2000

@dweeb First you need to edit your email out of the header. Never a good idea to put that on an open forum. Second go to the repair section and start over, this ask someone thing is not connected to the latest posts.

I’m surprised based on the age of the truck you’re not exempt from emissions…If I were you, I’d repost your original question over in the repairs section of the forums. This section isn’t connected to the main forum, and most of the regular mechanics (I’m just a DIY’er) don’t come over here. (also, please change the title of your post, Volvo is absolutely correct that you shouldn’t post your personal email address!)

Carb’d vehicles running rich usually means the idle mixture screws aren’t adjusted correctly, or the choke isn’t fully de-choking once the engine warms up. Mid-80’s carbs can be quite complicated, as the manufacturer often had to add electronic control gadgets to them in order to pass emissions. Those complications were a major motivation for them to switch to electronic fuel injection in the late 80’s, early 90’s.

So, as far as the carb goes

  • make sure the choke plate is fully open when the engine is warm
  • re-adjust the idle mixture screws according to Mazda’s procedure
  • verify any electronic control gadget which affects the carburetor is working correctly

It’s also possible the engine isn’t getting up to full operating temperature b/c of a faulty cooling system thermostat.

1 Like

Thank you very much. I was also told to check compression. I have to get to a garage. Thanks again.

  • List item
1 Like