1984 22R Fresh rebuild top to bottom. Fires up fine. Idles fine at 1500 rpm while warming up. After warm up the idle refuses to drop. I adjust it down via the adjuster screw on the carb. Problem is it just dies before I get anywhere near 800 rpm. I am running EngineBuilder 261 cam with a stock exhaust system, and stock carb. The carb was also rebuilt and cleaned. I also seem to have a slight miss. I obviously can't time it accuratly with the idle set so high. I can't find any vaccuum leaks. If I take it down the street it runs through the gears fine, but when I push in the clutch to stop, it just dies under braking. It refuses to restart after dying also,but will fire right up with some force feeding carb cleaner, etc. down the carb. Any thoughts on trouble shooting are welcome. This is my first foray into a carbed motor in many many years. The only thing that is not currently hooked up is the second O2 sensor that lives behind the cat. convertor. This is a California truck. When I replaced the exhaust front to back the new pipe did not have the bung for the O2 sensor. Any thoughts on that?

Thanks , Jeff

Not sure about the 2nd o2 sensor but mine did the exact same thing when I had my carb rebuilt, I traced it down to the Idle Cut solenoid, it's where the other 2 wires on the carb go, not the choke and not the vent, should be on the rear passanger side of the carb. Hook up to the batt directly, easiest to do through the plug itself, with some long spare wire. If it dosen't click then ya need a new one, it's probally stuck open, which will flood the motor when you stop and cause it to die. I perfected the art of 3 foot driving when I was dealin with this little number <img src="/forums/images/graemlins/lol.gif" alt="" />

If you haven't downloaded the FSM for your truck yet do so. There are (2) adjustment screws for "idle" control. From the passenger side looking in, the one closest to the front of the truck is the idle control. The one towards the rear next to the vacuum diaphram is the fast idle screw adjustment. Just wanted to make that clarification because I had these two confused when I first got this truck and it was a little frustrating to say the least. Everytime I would turn the A/C on the truck would idle up to around 2k rpm. <img src="/forums/images/graemlins/lol.gif" alt="" />

I have the factory manual. Idle cut off is working. I can hear it click. It has a new o-ring on it from the rebuild kit. I have no vac. leaks that I can detect. Tested with carb cleaner. no change in idle speed. Choke is working correctly as far as I can tell. I just can't get it to idle smmothly below 1500 rpm. I also have a huge stumble when I get on the gas quickly. If I rev it slowly no problem, but when I put my foot in it quickly, it stumbles hard for a second then goes strong. Also wants to die immdediatly when under braking. It does this only when I push in the clutch and quickly apply the breaks. Would a failing brake booster cause problems like this? I am no expert on carb. rebuilding, but I took my time and didn't have any trouble with it. The other puzzling thing to me is how it starts up great when cold, then slowly starts to run rough as it warms up. Once it's warm the idle starts to come down and then it usually just dies. It will not even think about starting again unless I dump some fuel down the top. Float level is fine. Fuel is in middle of sight glass and stays right there. I have not made any adjustments to the carb itself other than the main idle screw. All linkages seem to be correct. EGR is OK. This truck was on it's death bed when I got it so I can't say that every little thing under the hood is working correctly, but the major systems are all fresh right now. I am just operating blind when it comes to tuning carbs. All my other trucks are EFI. I may just let a pro fine tune this thing and be done with it.

Ok, now it's starting to sound like a fuel starvation problem. Have you checked you fuel filter and fuel pump? I had a very similar problem and found (2) fuel filters installed. One was under the hood which I found right away. That other was back by the fuel tank under the bed on the passenger side. That one looked to be completely clogged. I removed the new one under the hood and moved it back to the OEM location, replacing the old one. The filter needs to be installed before the fuel pump. Not after.

Also, check to make sure your timing is set to 0? with both vacuum advance tubes off.

Last, check you plugs to make sure they're tight in the head. If they're loose in the head they'll misfire from poor grounding.

Ok, one other thought berfore I go. You could also have a bad Accelerator Pump. If the carb is leaking down at night it will crank right off the bat in the morning but then run like crap when it runs out of the initial fuel load. That's why I really think you have a fuel flow problem. But it could be a combination of things as well.

Thanks for the replies. I have a fresh filter I need to throw on. I am still having a hard time with the starvation theory. The fuel level seems to be right on the money running or not. I suspect the slow speed jet(s) are not letting enough fuel through at idle. I will definetly put the new fuel filter on first, but I think I am going back into this carb for a look see. I really wish I had more free time to play with this thing. It's making me crazy having it just sit in the garage. If anybody has any more theory/thoughts, let em fly. I am determined to figure this out. It is gonna be something obvious at some point. I hope...
Jeff