350 SBC w/ Eddlebrock help

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I've got a pretty nice '79 FJ40 with a mild 350 SBC with a four barrel eddlebrock. It's shame to have to pour gas over the entire thing and light it on fire as I push it over a cliff but that's about how frustrated I am with the thing right now.

Latelly it's idling really high all the time and I can't figure out how to get it back down. I hooked up my timing light and have it set at 8 degrees BTDC. I tried to look up on how to adjust the edlebrock but all i've managed to do is get the engine to run a lot hotter now and like crap and still at a really high idle.

There's garbage on the net on what to adjust. Any article says to adjust this or that screw but don't show where the darn screws are or what they do.

Any help would be greatly appreciated at this point.
 
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have you got a model # of the carb. If the temp increased as you tried to adjust it, chances are you leaned it out. When you initially set the carb up, how was it running. Is this high idle just recently?:confused:
 
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Not sure what the model number is. Where do I look to see? This is a totally new event. It was running great. I made sure everything was clear and free of snags. I didn't set up the carb initially. It has a mechanical choke as far as I can tell.
 

Gumby

Supamod
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High heat and a fast idle suggest a vacuum leak. Gotta fix that before you can adjust it. You're running way too lean. You'll burn it up if you keep running it.

The only adjustments you have are on the front of the carb. Two screws stick straight out. Those are the idle mixture screws.

You also have a idle speed screw on the throttle linkage side of the carb. Turning it out should make the idle speed change. If it doesn't, you have other issues. A vacuum leak or a timing problem.

I hate those carbs off road. I'd throw it in the bushes and put a q-jet on it.
 
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Hi
First do you have the Q-jet Edlebrock 1904? If so this is the way to set it up:

IDLE MIXTURE ADJUSTMENT
The Edelbrock Performer Replacement Series Carburetor for Q-Jet
applications has conventional Idle Mixture Screws (IMS) that provide a
leaner Air/Fuel (A/F) ratio when turned clockwise and richer A/F ratio when
turned counterclockwise. The idle air flow is controlled by a conventional
screw that opens the primary throttles. The following procedure should be
used to set the idle mixture and speed.
1. Fully warm engine and ensure choke is fully open.
2. Install air cleaner.
3. Set desired speed with the air screw.
4. Adjust the IMS on one side to get the maximum possible rpm or highest
vacuum if you are using a manifold vacuum gauge. Do not go rich beyond
the maximum speed point.
5. If the procedure above changed the idle speed more than 40 rpm, then readjust
the idle speed.
6. Adjust the opposite side of that in Step 4 to get maximum rpm or vacuum.
7. Reset the speed.
8. Carefully trim each IMS to again get the maximum idle rpm or manifold
vacuum.
9. Go leaner just enough to get a 20 rpm drop in speed.
10. Reset the speed to the desired rpm.
11. This is a Lean-Best Idle Set. Setting richer than this will not improve idle
quality or performance, but could cause higher hydrocarbon emissions and
tend to foul spark plugs.
12. Emission legal carburetors #1903, #1904 and #1906 are supplied with
tamper resistant protective metal caps for idle mixture screw wells. These
covers should be installed following completion of final idle mixture
adjustments. NOTE: Use idle mixture adjustment tool K&D #2776 or
equivalent.

For more info:

http://www.edelbrock.com/automotive_new/misc/tech_center/install/1000/1904.pdf

If you have a non Q-jet Brock try this:

http://neptune.spacebears.com/cars/stories/carb.html
 
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didn't realize you were from the area initially. If yo can't work things out I may have a Q-Jet recently rebuilt from an early 70's Blazer. I'll check it out if you want.
 
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Set the choke to off, turn off the engine, take off the air cleaner, and then have a look at where the throttle linkage connects to the carb. Open and close the throttle by hand and have a look at what is happening mechanically. The throttle stop is one of the easiest settings on a carb and they are all basically the same. You should be able to see the screw that adjusts the idle speed or stops the throttle at a set point. Its generally on the drivers side of the carb towards the front of the carb.

Also, don't overlook the linkages. Imporper adjusted or installed throttle linkage or choke linkage can also cause a fast idle and turning the throttle stop screw won't do a darn thing if these are not set up correctly. You can disconnect the choke and throttle linkages and set the carbs choke manually to off and start it up and see if the idle can then be adjusted. This would eliminate any linkage problem. Basically, the linkage should allow the throttle to completely close.

Also, although unlikely, make sure you don't have a fast idle solenoid keeping the throttle at a fast idle. These are generally used to speed up the idle when certain accessoroes are turned on like A/C.
 
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Maladjusting the idle mixture setting WILL NOT cause overheating.

A maladjusted idle setting can (like duh) cause a lean idle, but there is not enough BTU output at idle to cause overheating. At the most you'll get missing or stalling, or have to raise the idle speed up.

Too lean a condition that causes overheating is from having jets too small, or in the case of the Edelbrock carb, the mixture rods too large in diameter, or a combination of both. If the carb did not cause overheating before, and the jets and rods have not been changed, then mixture is not the problem.

It is possible to get overheating from the timing being way off. Personally, I've never seen this happen at idle. It can happen under cruise and especially power conditions.

The likely culprit is a vacuum leak. Check all vacuum hoses or plugs. If you are using stacked insulators under the carb, these can be notorious for leaks. Check the PCV setup. Make sure the valve is not stuck open.

A bad vacuum advance OR a stuck breaker plate on the distributor can also cause overheating. If the timing remains close to TDC when it should be advancing, then overheating can occur. Make sure the timing advances when you rev the engine. Make sure the vacuum advance hose is on the right port on the carb. One port is "ported" or "timed", the other is constant vacuum. For nearly all distributers, you want the "timed" or "ported" port. On the Edlebrock Performer, there are two small vacuum ports on either side of the idle screws, plus a larger PCV port centered below. The "ported" or "timed" port is the one closer to the choke side of the carb. The port closer to the throttle bracket side of the carb is the full vacuum.

You can also check basic timing and look for vacuum leaks and other problems with a vacuum gage. You can hook this up to a port on the manifold or the full vacuum port on the carb.

These links might help...

http://www.users.bigpond.com/ergoff/vac1.htm

http://www.earlycuda.org/tech/vacuum2.htm

http://www.ctci.org/membership/Gilsgarage/Distributor.htm
 

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