Edelbrock 1406/1405 woes...(long)

[trailpsycho]

I have been running the edlebrock for about 9 or so years and for the most part its given great service. Its been rebuilt twice, most recently about 3 months ago with new seals/kit. It has been running great until last week, when it noticed that it would load up once the truck gets warm, although I can tell the difference even when its cold. Even on the highway at crusing speed, I could tell it was dumping excessive amounts of gas.

The carb was tuned in very well prior to last week, and just seemed to start to deteriorate. I have run through the gas that was in the last tank and am on a second tank now (seems to be using more fuel than normal). At first, I thought I was having ignition problems (slight misfire, loading, running very rich, I though bad wires, etc), so I replaced the cap, rotor, plugs, wires, coil swapped the dizzy, cleaned the air filter and the problem is peristent. I dont want to throw a bunch of more money at it. This brings me back to the carb, which I have tuned about as well as I can get it...

what would cause it to load up?? Float levels, accelerator pump, debri? I am going to take it apart again tonight to see if something has made its way in, however, I have two (2) fuel filters in line, so I dont think that is an issue. Any clues on what to look for going in would be great. Thanks.

NO, I dont want to dump it for a Holley, b/c I already have my 5.0; I am just waiting for the $$ to build it right, get the EFI harness, etc. Spring. I need to keep this running well through the fall as its my DD, etc and there are surely a few road trips and at least one more trip to the Badlands before ol' man winter arrives. Thanks for any insight.

John

 

[wildbill]

;D ;D ;D Some real fine dirt on the needle seat and or a bad float or not set right can cause it to load up good luck. ;D ;D ;D Bill %)

 

[Mr Joe]

I agree with Bill... Sounds like some debris in the needle seat.... I'd take it apart and squirt some carb cleaner in there.

 

[Madgyver]

Tie your choke open, see if that makes a differance.
Adjust the idle screws and if there is no change in the idle than your air bleeds are clogged. Clean it up with carb cleaner spray.

It sounds like the eccessive fuel is being sucked through the transfer slot in the venturis which means the idle circuit needs adjustments/cleaning.

 

[trailpsycho]

I just got done rebuilding the carb (disassembled, cleaned, blew out all orifices, reassembled). I saw nothing inside that would have lead me to believe there was any debri or problem.

I have the idle air screws at 2 and a quarter turns, which has always been "the spot". I even played with them a little and the best idle was at 2 and a quarter turns out. I didnt mess with the idle-speed adjustment; it was at 650 this past w/e when we put a tach on it and I can tell its right around there now. It ran awesome once it got fuel from being empty, the throttle response was crisp on the first half of the test drive out to the gas station (fuel prices are on the rise here again). Fired right up on the return, idled great. But as you get on the gas, theres initially crisp response, if you hold it above about 2000 rpms or so, theres like a pulse. I wouldnt call it a miss, but like its bogging; its subtle, but very noticable. If you accelerate hard its not as noticable, it will pull through OK.

The engine was @ 175, so its not "hot", but that is the temp it normally runs at. However, the rest of the way home the "pulsing"/surge at cruise was present. When I got home, I let it idle, the idle was smooth. There was a little richness from the tail pipe, but it was not quite as bad as it was before I cleaned the carb. I didnt notice it driving or at a standstill, whereas earlier today it was very noticable. After a couple of minutes at idle (rechecked timing: still set @ 16-18 advanced and just relooking over everything), it stalled out. I know it would have restarted, but its getting late here and I was/am frustrated.

Another thing, earlier this evening when I went to remove the carb, the truck was still warm and as I removed the fuel line, the line seemed somewhat pressurized. I am not running a fuel pressure regulator between the manual pump and the carb. The only thing I havent changed is the fuel filters...the one closest to the car is glass and it looks fine, the one just prior to the pump is unknown-about 7 months. I would really appreciate any other ideas...why woudl it do this only at running temp. I have thought about vapor lock, but I have my ss fuel line coming from the carb between the block and PS pump then out around the dizzy and a inch or two above the valve cover to the inlet...it should be fine, has been for a long while...til recently (it hasnt been hot here either)

Any additional insight is appreciated. Thanks for your time and attention.

 

[broncnaz]

Some things to think about. 16-18 degrees intial timing is to much Even the experts like jack rousch recommend only 10-12 max bump it down to about 12 see if that helps. Easy way to tell is loosen the dist and start the engine then rev it up to where its missing/bogging and turn the dist see if it smooths out. I bet it will. I set my timing like this all the time then check with a light and it usually ends up being 12 degrees. Gas nowadays sucks so less timing may be needed. As for your fuel line pressureized not really a big deal just means the needle seats are holding there own and the fuel pump was stopped on the pressure stroke.
Another possiblity is that the screen on the fuel pickup in the tank is clogged up years of crud will collect on the screen and plug it you could blow compressed air back through the lines to see if that clears it up if it does than you need to clean out the tank or it will happen again.
You could change that first fuel filter as it will plug up first they are cheap and then you know that thats not the problem. Also check all the rubber lines make sure the connections are tight and there are no cracks in them.
Thats about all I could think of right now seems as though you've covered the rest good luck.

 

[Broncosix]

Too much timing. 12 degrees should be fine. Also check total timing, should be around 32 degrees. (total= rev engine 3000 rpm and check timing).
What about the fuel filter?? Did you replace it?
Give me a call when you finally get to work. Ha

 

[RangerRob]

Other things to check:
Vacuum lines. Make sure you don't have a leak somewhere.
Float level. Surging can be caused by improper settings.
Metering rods and Springs in properly and not binding.
Distributor vacuum advance hooked up to ported vacuum?
No leak at base gasket?

If you took the jets out during the rebuild, make sure they went in the right spot. My primaries are .98 and the secondaries are .95.

Good Luck!!!