Off Roading Forums banner
1 - 3 of 3 Posts
G

·
Discussion Starter · #1 ·
I just tried to take my edelbrock 600 cfm, #1406 carb to stage 7 on the scale for calibration. I tried it and the engine sputters. I am at 3000= ft of altitude. I had it set at about 1-2% lean before and it was just a little too rich, just a tad. I then tried to set it at about 6% lean, one of the best engine builders locally said the carb would run fine there, he had done it thousands of times. I tried it and then went for a test drive. The engine sputtered at idle, it was cold so I took that into consideration. I then ran the engine about 2 miles and it sputtered whenever I let off the gas. I am assuming that the carb is just too lean now. Could someone comfirm or deny this for me?
THANX

/wwwthreads_images/icons/smile.gif 1976 CJ-7,CHEVY 350, 33'S, 3" LIFT, THAT COVERS MOST OF THE MAJOR STUFF /wwwthreads_images/icons/cool.gif
 

·
Registered
Joined
·
168 Posts
If you are having trouble with your idle you need to re-adjust your mixture screws. The idle and primaries are two different systems. A rod/jet change should have no effect on idle performance. The primaries come into play as you depress the accelerator. I tried a similar set-up on a 304 w/ the edelbrock 1405 and had a flat spot while cruising. Seems there is no good middle ground. Either a tad rich, or a tad lean. I would avoid going too lean unless you have an air pump injection system going into your exhaust manifold to keep the valves from getting too hot and warping. Lean=hot. Hope it helps.

Nuke the unborn gay whales for Jesus
 
G

·
Discussion Starter · #3 ·
I think that I have nailed the problem. I took the intake hose off the carb and it sprayed gas about 3 feet. It turned out that the brand new, 2 weeks old, fuel filter was not working properly. It is a see-through fram designed for 3/8" rubber line. I have used these filters for a year now and replaced several of them. I have a filter, new, in the tank and another one just before the carb. The one before the carb always gets clogged. I think that the rubber patch lines, new also, are letting black deposits into the filter and clogging it up. At any rate, I put on a new filter and retuned the carb the way it was before. No bad idle problems now. This weekend I will try about four different settings for the altitude I am at, 3200 ft. Settings #5,7,a custom one, and another one that a friend from Edelbrock Corp. told me to try. I have a sniffer at my disposal so that will help at idle. I reset the air mixture screws, timing, and idle set screws today and went wheeling. The timing was set by ear and will be dialed in this weekend. I can romp it for a second, WOT, and it will not backfire. If I hold it at about 3500 for about 4 seconds it will very slightly backfire. No pinging, remember this was set by ear, will dial in this weekend. I wheeled a trail today that I had wheeled in the 4-runner. The Jeep ate it up where the 4-runner tucked tail. Biggest problem was getting the tires NOT to spin on the trail, soggy snow melt mud. I also reset the float rest position to 9/32 to check the off-road needle and seat kit. I figured that I would try a few different levels to see what each did, only takes a few minutes and I can do it while on the trail. I took it up a hill the other day that some of the quadrunners were having trouble with bogged a little but still ran. Damn I love Jeeps. I think that you are right about the tuning procedure, if you only use the settings listed in the book. I found one that works really well for my altitude that isn't in the book, but I will have to lean the secondaries out a touch. Or another setting that I will have to richen up a little. Knowing one of the guys at Edelbrock personally really helps to pick custom settings. How did things turn out with your Edelbrock?

/wwwthreads_images/icons/smile.gif 1976 CJ-7,CHEVY 350, 33'S, 3" LIFT, THAT COVERS MOST OF THE MAJOR STUFF /wwwthreads_images/icons/cool.gif
 
1 - 3 of 3 Posts
Top