My 92 3.0 4x4 pickup runs great until getting stuck in traffic on longer drives. I've noticed excessive pressure building up in the fuel tank evidenced when taking off gas cap. I did the charcoal canister blow thru test and it seems restrictive (gonna hit it w/compressed air asap). Sooo, can a clogged canister hurt performance and cause a hot running engine? Recent coolant and thermostat and water pump change, new timing belt and timing is dead on, new plugs, clean air filter, new fan clutch is working correctly, recent cat converter, and just passed emissions test. I'm thinking I need to have the rad. rodded out, but anything to this canister idea? thanks guys.

 

I would do a temporary test by bypassing it with a vacuum fitting to see of that ails any of your issues. As far as overheating I can't see anyway in which a clogged canister would contribute as that would be limiting purge air to the plenum (lowering combustion chamber temps). Symptoms of a restricted Canister would be much more likely to cause excessive pressure build-up in the EVAP system like you were referring to.

 

The evap system has no measurable effect on coolant temps. Most likely this is a partly clogged radiator.

I had my rad out recently while doing some unrelated work. I sprayed through the fins and could not believe how much mud and debris came out. You might want to just spray a hose from the engine side out until the water runs clean. This is simple job and won't hurt to try.

jrohland