[rfmaster]

Originally Posted by 72freak

I dont have any experience with this crazy pre-87 emissions stuff. I dont have another one close by to compare it to.......We picked up this crew cab a few weeks ago.....running great. It looks like there may have been a smog pump at one time that was cut off??? A few tube things up top on each side and two plugs that go no where. It will throw a "check engine" light when on the highway. I am sure it has something to do with the unplugged stuff.

1) any pictures of what is should look like?
2)Will the plugs that arent hooked up effect this check engine light?
3)If so can they be jumped off?
4)Where do these pinched off tubes up top go to?
5) CHECK ENGINE LIGHT....are you kidding me...WHY? Whats it supposed to be telling me?

Im sure I will eventually change the intake, carb and exhaust, but for now Id like to make sure its right.

Thanks for your help!

In the Photos it looks like some one really hated AIR system - (air injection) - the two plugs were used for AIR diverter valve which by-passed air from the AIR pump when not commanded to inject air into exhaust manifolds. As for check engine light I have to assume that you have CCC (computer controlled carb). Take a look at you carb it should have a model cast into it - probably M4MED or ???. Inside cab, look left of the steering column for ALDL connector.



If you have one this also means that you have ECM controlling carburetor. To determine what is causing SEL to be one - short pins A&B with a paper clip and turn ignition on, but do not start engine. SEL should blink code 12 3 times followed by the offending DTC.

//RF