My truck has been running fine for months now, but recently it has been having some idling issues. After driving and bringing the engine back to idle the engine would idle very low and rough (~600RPM or lower), but sometimes it would idle just fine up around 8-900PRM. My first guess was a vac leak, so I replaced all three of the gaskets for the weber 38/38 carb and adapter plates and this seemed to help a little. The only other vacuum lines i have to check are the vac advance and brake booster lines and these are ok. Timing is set up around 9deg and I recently cleaned the air filter. After replacing the carb gaskets last night, it was still acting a little funny so I replaced the spark plugs this morning with some NGK V powers gapped to .031" as per the owners manual. The truck has had a very slight coolant leak for awhile but has never overheated. Could this possibly be a headgasket leaking? I changed the oil last week and the oil looked fine. Any thoughts on a solution to this problem?

 

is it your linkage? i know my '79s factory linkage can get stiff and thust not return all the way, or there can be play in it. mine either idles at 800, 1000, or 1300RPM depending on how fast i let off the throttle and let it snap back

 

My viewpoint is that you should place a high priority on where that coolant is going. Reason is simple. It probably IS a HG, and, if it is, you can repair it now for 1/3 to 1/2 of what it will cost you to wait until you have a "piston scored" or cracked block. Don't mean to sound alarmist, but waiting until the thing overheats seems to be a recipe for bigger problems based on lots of experience in this forum, not to mention my own.

So there are a bunch of ways to find out where the coolant is going. I'm thinking the fastest and cheapest is a pro that can do a leak trace with a fluorescent dye.

I'm also thinking a "leakdown test" might be a good choice as well.

So the bottom line is, you were sharp enough to catch the fact you were losing some small amount of coolant without overheating. Take advantage of that, and figure out where its going. Fix that, and then worry about the idling problem.

 

Thanks for the replies so far!
Kyle: It's not the linkage (it goes all the way to the idle speed screw), that was one of the first things I checked because it used to bind somewhat when I first put the carb on a few years ago.

I think it may still be a vacuum leak of some type. Last night when i was looking things over, i noticed a whistling noise that sounded like it was coming from the back of the engine. I felt around and discovered that there was a slight vac leak on the back side of the carb at the base. I made a new gasket out of some thicker material and bolted it back together and after tuning it last night it seemed to run great, dropping down to idle at 900. This morning however, when i first started it it idled ok, but by the time i got into town (~6 miles) the engine rpms would drop way down and the engine would die. It runs fine when the vehicle is in motion, just the idle seems to be off. Is there anything that I am overlooking? I would need to order parts soon so that I can solve this this weekend.

 

Any input? I would like to order a head gasket today if possible if thats what everyone thinks the problem is...again, it drives fine but cant idle worth a darn

 

Your top priority (to minimize total cost of repair) should be to trace where that coolant is going. Could be out the exhaust for instance. A good radiator guy that knows how to do the fluorescent dye trick could tell you where that coolant is going. Once that is solved/fixed, you can work on the idling problem. (that sounds like a problem I've had on my 3 Liter, but never on the 22re)