ok well sometimes i start my truck and the idle will be very rough and die. then sometimes it'll start up and run fine. it idles at about 700-850 rpm and when its rough its at like 500. the truck does have a couple exhaust leaks and im guessing the spark plugs could be pretty bad because of it so i was wondering if that could have something to do with it.

oh btw its a 87 22RE

um let me know what you guys think and what i can do to take care of it.

thanks a bunch!

oh also on a side note, my rear defrost doest work. the button works and light comes on when i turn on the button. what should i check and where to get it working cause it blows having a foggy rear window lol

 

Check engine light come on? Any codes?

 

even if the CEL doesn't/didn't come on, still check for codes.
How long does it idle before it dies?

 

The fuel mix when (engine temp) is cold is more rich than when warm. Spark plugs can play a major role in engine operation, so get good plugs, gapped accordingly.
Fuel injector condition can also play a big part. If the pattern is uneven or 'drips', there's some fuel that's not mixed with the incoming air charge and puddles, drops and such of fuel do not burn like gasoline evenly atomized (mixed with air).
Other issues such as low compression, ignition timing, sensors, the idle air valve / auxillary air valve operation, exhaust backpressure, etc. can affect engine operation as well.

As for the rear defogger/defroster, assuming it's the wires on the glass type, check that one of the wires is continuous to ground and the other gets voltage when you hit the switch. If both of those are true, check the resistance between the terminals on the window. If it's open / infinite resistance, something is wrong with the traces- either they're all cut due to some issue or one of the connections for the wires is broke. If you're not getting a ground and voltage on the wires... well that sort of tells you where to start looking. If you get voltage on one and no ground on the other, the issue is with the ground side and conversely if you have one with continuity to ground and not getting voltage on the other the problem is with that other wire.

 

ok cool thank you