92 Suburban 454 Engine Runs Lousy

[captdh]

I have a 92 Suburban with a 454 engine, runs lousy, not much pickup, tachometer fluctuates, backfires when accelerating and towing (once engine is heated up), and surges going down the highway. Also after towing awhile it starts to run hot. The radiator has been rodded out (it was clogged) and the cooling system is now in good shape. I think it might have something wrong with either the fuel pump (as in pressure), the coil might be dying or the EGR system is faulty. Also on occasion when the engine is cold the engine will just die within a minute or so after starting it, up to three times and the check engine light comes on. The code readout (I believe it was a 32 or 42) says it has something to do with either the EGR system or the fuel pump relay. I was trying to check out the EGR system today to eliminate it. The EGR valve seems to be working properly but this truck has an EVRV that I am not sure I am checking out properly. I can't seem to get any audible click out of the valve when I apply 12V to it. Seems a solenoid would make a click of some sort. Also whether I apply voltage or not to it when I apply a vacuum (using a hand vacuum pump) it will not hold it which seems like it has failed. Can anyone give me some advice on how to properly test out the EVRV? Or any ideas about what else to check on the truck to isolate the problem with it running so poorly?

[tirefryer93]

Give the big block a good tune up first. Plugs/Wires/Cap/Rotor/Fuel Filter. Take the vacuum line off the EGR valve, and plug it with a cork. If you do not hear both the fuel pump and the switch of the relay when you first turn the key to run, (not start) then you should diagnose either of those for failure.