bRunner

OK, so I recently did a head gasket replacement.
During the replacement I replaced the thermostat, engine coolant temp sensor, pcv valve timing belt, spark plugs(ngk didn't check gap will do),wires dist cap/rotor, put seafoam into the gas tank, new oil/filter/coolant and some vacuum lines.
During the restart I put a fuel line on the vacuum line (have fixed).

Since the fuel burn out from the exhaust (changed oil);, the engine has run great for a couple of weeks, but I had to make a run to a town 60mi away and when I got back to town the motor decided to run like crap.
Low idle speed, Vibration at times acceleration is choppy, and a completely new smell from the exhaust.
the motor starts up and idles fine when cool. Then once warm,-low idle speed 500rpms ,
bad acceleration, and a new smell from exhaust. the oil pressure/temp seem normal no fluid leaks, engine seems to run fine at higher rpms( 3k and above). I have been through a whole tank of fuel since the seafoam.
What could this be?

revbrad

This sounds similar to some of the symptoms I had with my truck. The first thing I would do is check for vacuum and/or air leaks. Especially around the air intake silencer. I would also strongly recommend the ISR (Intake Silencer Removal - can be found in one of the other sub forums) mod. If this does not eliminate the problem begin checking things like TPS (Throtttle Position Sensor) and the Oxygen sensor. General Tune up things may also be effective such as plugs, wires, etc.

gilbert46

leaky injector/ cold start injector?

When i got my truck the thermostat was closed so someone dropped the idle so the cold idle was 800. when i replaced the thermostat the truck warmed up and died at slow idle, upped the idle back to regular and all is well. I think its idling at 1100-1300 cold and 750 hot.

MonsterMaxx

Do a code pull from the computer just in case it's a sensor that's come unplugged, but I can't think of any sensor that if unplugged the engine would run at all. But check for codes anyway. It could be a quick fix.

I'd say check for vacuum leaks. I think you forgot to tighten something. See if maybe the resonator box came loose. The one for the reed valve (the great big one under the manifold) is nearly impossible to connect w/o lifting the plenum, so it's unlikely it'd disconnect, but might be loose - check the clamp.

Of course don't forget to top off your blinker fluid, oil the muffler bearings and check the tension on the carburetor belt.

bRunner

Solved! spark plug wires on 3 and 5 cylinders. The spark was arcing to the egr body from poor routing of wires no fire + 1 cylinder firing on one side = bad vibration bad acceleration and poor idle speed. Quick fix new wires and modified generic wire guides. I had all of those plastic guides break on me. much better now. thanks for the help