I've asked this in another thread, looking for a little more specific info if possible. My 99 Vortec big block has an intermittent miss on #4 and constant miss on #3. Injectors are new Bosch, regulator is new, distributor, cap, rotor, plugs, wires are all new. Upper/lower intake gaskets are new. Fuel pressure and compression are all good. I'm at my wit's end and way beyond my abilities to diagnose this. It seems to run ok when it's cold but once it warms up it gets worse. I've ordered a fuel injector tester to check the injectors on 3 and 4. The injectors came from ebay and I suspect that maybe they're Chinese copies, if those two are the problem. I've contemplated a Sniper but ideally would rather the factory system work like it should because if the injectors aren't the problem I've fixed nothing.
Is it important that the two misfires are directly across from each other? There's no noise coming from the engine, no ticking or anything that might be bad lifters, I just really don't know where to go short of testing those two injectors and hoping they're the problem so I'm open to suggestions.
Is it important that the two misfires are directly across from each other? There's no noise coming from the engine, no ticking or anything that might be bad lifters, I just really don't know where to go short of testing those two injectors and hoping they're the problem so I'm open to suggestions.