Hi, New guy with a sick truck.
I have run into a problem with the old plow truck running lean. Of course it has a used Qjet that works well except for being lean. Does anyone have or know where I can locate a jetting chart for the 74-79 K 1500 model with a 350 ci and an auto trans?
Ihope that I haveposted this question in the correct place.
Thanks for any help.

 

Where the heck is CHEVY LOVER ON THIS ONE....

 

Just some information I found. I haven't had the pleasure of messing around with a qjet in MANY years. I still have 2 of them that I used on my Chevelle before I went to a Holley carb.

Rochester Quadrajet Manual - The Old Car Manual Project

The Rochester Files

My Quadrajet Tips

Have a read through there. But yeah, Chevy Lover could probably answer your question for ya. I'm bookmarking all of those links just for my own information when I get to rebuilding my Chevelle.

 

These guys are funny! I'm no wizard, I just have old trucks.
I've been very busy at work (really cuts into my leisure time)
Kyle came up with some great technical info....as per usual.

I love the Q jets. The only time I have had problems with a lean running is when I've had a blown base gasket or sloppy throttle body bushings. I'd check the throttle shaft for play first.
I have (somewhere) a small container of different sized jets and in the past I have used them to experiment. Usually after the installation of headers and different ignition systems. All I have done is check the jets in the carb (the size is normally marked on the jet, the ones that weren't I measured with drill bits), then I put in a larger jet, if I had a 60, I put in a 70 etc..

The other things to look at for lean running would be a partially plugged exhaust, sticking EGR, intake vacuum leak, vacuum hose leaks.

 

Well ChevyLovr since you got the old trucks that makes you the unofficial wiz at them...but if he does not have any of the conditions you describe might he not need to find some old fashioned liquid carb cleaner and a Q-jet rebuild kit (if they still can find them) and just do a thorough internal cleaning??? If GM is correct and the MTBE additive is what is clogging up the "POPPET" valves on the CSMFI fuel injection might it not varnish up the jets???

 

Ya, cleaning a Quadrajet can do wonders. (replace the float too) Carb kits are available

 

Well thank you for all the input.
I did findinformationthrough a link fromthis site that had all the information a guy could want as to repairing or jetting a Q jet.
Dumb me I didn't mark the site.
What I had found when taking the carb apart was someone had installed the secondary metering rods in the wrong position.(mounted to the inside of the hook)The rods were binding in the holes and were stuck open a little.
After fixing that the truck runs much better but isnow a bit lean after it reaches operating temperature even though it is jetted richer than what is called for.
ThisI can live with it since it never leaves the yard and is no longer using4 gallons an hour.

It was kind of bad when the neighbor asked if the truck was a diesel because of all the black smoke.

Thanks again for all the ideas.