I have a 1985 pick up with a 305. This just started this morning. The truck idles fine in park, as usual. As soon as I go into reverse or drive it idles real choppy and sputters. Cruising around at a steady speed and rpm it doesn't run too bad, but when I go up hill(at higher RPMs)it gets really bad(sputtering and no power).
I checked my plug wires and connections and checked for vacuum leaks. Everything seems to be OK.
What else should I check?
Thanks,
Mike

 

check the plugs, obviously. check the carb to see if it is flowing properly. check the dist. cap and rotor. is it misfiring? any frayed wires?

 

egr??

 

the plugs and wires are fairly new. What should I look for on the distributor? I'm pretty clueless when it comes to carbs also I took the EGR off a couple of years ago.

I changed the fuel filter today. That wasn't it. Could it be the fuel pump?

It only happens when I'm in gear. I revs really nice in park or neutral.
Any other ideas or info?
Thanks,
Mike

 

distributor most likely as stated above...

 

change the distributor cap and the rotor button. shouldn't be too expensive and i'll betcha that is what is causing it.

 

Well, it wasn't the cap and rotor.
I double checked the plug wires and vacuum lines, all looked ok. could I have a clogged Catalytic converter??? Still, Why would it only act up when I'm in gear?

 

Anybody have any other ideas before I take it to a shop????

 

What kind of carb is on it?

 

I have an '86... 305 with a 4 barrel. I've experienced similar issues before... replaced plugs (which looked like charcoal) and the distributor cap and button (burned). To this day I have no idea how it was running, let alone firing. But if you've checked ignition, fuel filter and pump are good, and everything else looks good, I'd look at the carb. If it's not that... then I'd say you've got a good case of the gremlins.

The only other thing that I can think of is that there's a vacuum line that comes off the transmission on the passenger side, if it's not on there it might be the reason why you're revving fine in park and neutral, but not having much luck in gear.