1988 B2200 problems
 

So first off the check engine light comes on when I am not accelerating and when the engine is cool. When it warms up as I accelerate the light turns off when I am not acclerating the light comes on and at stop lights the check light is on. Second thing is from time to time I hear a ticking noise it seems to be consistent with the engine speed as it get louder and faster as I accel.

Today I just went for an emission test in AZ and it failed the pressure test and the carbon monoxide emission. My truck has passed the califorinia emissions test and last month it passed the texas test too. The guy at the test center handed me a sheet saying the the pressure failure is due to a leak between the charcoal canister and the sealed filler cap. I haven't seen any gas leaking under the truck so I am confused. Any help would be very much appreciated.

1988 Mazda B2200 shortbed automatic

Are you sure that's a "check engine" light and not the charging light, like maybe the alternator belt is too loose? My '88 (Arizona) apparently doesn't have a check engine light, just the Malfunction Indicator Light which came on at 60K, 80K, etc.

I remember one time mine was at emissions testing, and it took the guy a while to find the correct vacuum line to clamp off so he could read the pressure of the fuel tank system. Those guys are NOT mechanics, he could've clamped off an incorrect vacuum hose. After that I paint-marked the correct hose for the future. So that could explain that, or maybe you just have a broken or disconnected vacuum line somewhere in that system, you wouldn't see any liquid gasoline.

thanks
 

I saw that it had a mil light and I saw that you have to switch a connector under the dash at those intervals you specified. I tested the lines up to the fuel tank and they were good so there is a leak in the tank.

At 60K miles, 80K, 120K, etc., the Malfunction Indicator Light will come on, supposedly so you get dealer to check emissions but more likely so they can try to sell you a timing belt replacement. By the way, do get the timing belt replaced every 60K miles, and maybe get the water pump changed at the 120K point along with it, as it's an internal water pump, behind the timing belt, and mine started leaking at that point, so it's a big labor savings $$$ to do both at once. The Malfunction Indicator Light is re-set by swapping a wire push-on connector under the dash, driver side, right next to the firewall; it's hard to see, lie down and look up, there will be a bare connector, just swap it, then swap back next time the light goes on at that set interval.