Can't get it to idle

[Ackattack]

I've been tinking with my 69 pickup, but I can't get it to idle.

I tore the engine down, put all new gaskets in it everywhere, and put it all back together.

I'm running an edelbrock 600 manual choke carb that I recently rebuilt. I also have an HEI distributor that I also recently went through. New plugs and wires.

I can get it to stay running about 1400 RPMs, if I dial the idle speed screw down or open the choke, it will die. I played around with the timing (can't really set it, since it won't idle low enough to really set it).

I screwed the idle set screws all the way down, and then backed them off 1-1/2 turns, and then a little bit more playing around with them.

I was thinking vacuum leak, but I can't feel anything. Anyone got a good way to check for vacuum leaks?

Any other suggestions? I feel like if I put a new carb on it, it would work fine, but that's a lot of money for a hunch.

[C. M. Wolf]

Frankly, if a vacume leak is suspect, replace all the hoses,(they're cheap and this basically removes that from the equasion).

Did you use any gasket sealer when placing the carb back onto the intake? (If these surfaces aren't a good mate, this might be a good idea).

I would then close your jet adjustment screws on the carb and then open them by properly counting the correct/recommended turns they require to open for your engine.

Then you're still going to need a timing light to check for correct timing, or you can play with this until the cows come home and still not get it right. Or if you know someone with a "Dyno"...

If you still can't get it to idle, you might want to make sure the distributor isn't set one tooth foreward or back from it's proper placement. This can be a nag, because just one tooth off can screw you every time and it's sometimes too easy to make that mistake .

It's a thought, anyways.

IHTH

Michael

[Ackattack]

I cleaned up the intake manifold mating surface, carb adapter, and used new gaskets when I put it together. I blocked off the brake booster port and pcv valve port with no change.

What I'm saying with the timing is, it is idling at 1400 rpms, so it is getting some mechanical advance, so I can set it to say 4degrees BTDC.

Might have to check to see if it is one tooth off though.

[C. M. Wolf]

Originally Posted by Ackattack

...

What I'm saying with the timing is, it is idling at 1400 rpms, so it is getting some mechanical advance, so I can set it to say 4degrees BTDC.

Might have to check to see if it is one tooth off though.

Hummm... running @ 1400rpm at 4 degs BTDC... it's sounding like the distributor is mis-set on the gear more and more. I think I'd check that first. then go to a dyno, if that pans out to be not it.

Is it possible to have set the distributor to an advance position when it was rebuilt? (In other words, the distributor gear may be in correct placement on the cam and the internal line in the distributor might be off... ?) That may bear checking too.

IHTH

Michael

[swamp rat]

I would say that as long as your certian that all the linkages are properly set then 1 1/2 turns on the fuel screw is too little and you should have about 2 1/2 turns to start with and up to 3 turns to allow more fuel to the idle circut. At 1400 RPM your opening the butterflys and pulling fuel from your jets not the idle circut, as you back off the idle screw your closing the butterflys and blocking the vacume to the jets thus not pulling the fuel from the jets. if that won't do it then i would question if the idle circut wasn't blocked with debree. Go ahead and turn each fuel screw in untill "lightly" seated then back it out 2 1/2 turns and try again

To check for vacume leaks on the carb or intake you can spray short shots of wd-40 at the gaskets, one spray then wait a sec, if the idle increases then it sucked in the wd-40..

As for timing, this will get you close enough for an initial fire up or initial tune: Pull the #1 plug and "bump" the engine over ( helps to have a buddy or a remote start switch or both) with your finger in the #1 spark plug hole, when you feel the compression start to push your finger off the hole your on the compression stroke, manually turn the engine to move the timing mark to 8 degrees before top dead center, then pull the cap and look at the rotor in relation to the #1 position on the cap. If nessasary loosen the locking bolt the turn the distributor to line the rotor up with the #1 wire location on the cap. The rotor and cap should be pointing toward the #2 cylindar, if not then the distributor may be off a tooth. But if the rotor is not pointing at the #2 cylindar don't worry about it unless you cant adjust the timing without the vacume canister hitting the fire wall, it can be a tooth off and not be a problem.

scroll down to the 4th enging picture.
http://www.offroaders.com/tech/V8-en...ring-order.htm

[oldiron]

I have also heard that edelbrock carb are sensitive to fuel pump pressure. Too much and they are hard to idle. I have mine set to 4 1/2 lbs of pressure.

[dznucks]

Good point about the fuel pressure....do you have a regulator?

To set your timing, you should actually rev the motor up to 3200 or temporarily remove the weight springs (replacing them after max timing is set), then set the max timing to 36 deg. That way you know your initial timing is correct and you can tune the carb around that.......assuming your dizzy is in correctly.

the edelbrock carb is not a difficult thing to disassemble, blow out and reassemble. You might have had debris become loose when you let the carb dry out during your rebuild. it wont take much to cause some issues.

[Ackattack]

Originally Posted by swamp rat

I would say that as long as your certian that all the linkages are properly set then 1 1/2 turns on the fuel screw is too little and you should have about 2 1/2 turns to start with and up to 3 turns to allow more fuel to the idle circut. At 1400 RPM your opening the butterflys and pulling fuel from your jets not the idle circut, as you back off the idle screw your closing the butterflys and blocking the vacume to the jets thus not pulling the fuel from the jets. if that won't do it then i would question if the idle circut wasn't blocked with debree. Go ahead and turn each fuel screw in untill "lightly" seated then back it out 2 1/2 turns and try again

To check for vacume leaks on the carb or intake you can spray short shots of wd-40 at the gaskets, one spray then wait a sec, if the idle increases then it sucked in the wd-40..

As for timing, this will get you close enough for an initial fire up or initial tune: Pull the #1 plug and "bump" the engine over ( helps to have a buddy or a remote start switch or both) with your finger in the #1 spark plug hole, when you feel the compression start to push your finger off the hole your on the compression stroke, manually turn the engine to move the timing mark to 8 degrees before top dead center, then pull the cap and look at the rotor in relation to the #1 position on the cap. If nessasary loosen the locking bolt the turn the distributor to line the rotor up with the #1 wire location on the cap. The rotor and cap should be pointing toward the #2 cylindar, if not then the distributor may be off a tooth. But if the rotor is not pointing at the #2 cylindar don't worry about it unless you cant adjust the timing without the vacume canister hitting the fire wall, it can be a tooth off and not be a problem.

scroll down to the 4th enging picture.
http://www.offroaders.com/tech/V8-en...ring-order.htm

That is pretty much how I set the timing when I put the thing together

What you're saying about the idle circuit makes sense. I'll back the screws out more, and if that doesn't work, see about pulling the carb off and cleaning it.

New fuel pump and no regulator.

[bigguy69]

i had the same problem,inhad to put a regulator on mine and adjust down to 5 pounds

[timjt]

I think swamp rat is right, the fuel screw may need about 1-1.5 more turns, I bought a truck for parts with no idea what was in the engine but its edelbrock seemed to work best at about 8 turns out!! it was a peice of crap but it sounded cool and had a really straight body

[Ackattack]

So I pulled off the distributor and made sure the mechanical advance and vacuum advance were working and not siezed up (had that happen one.....wet washington winters will do that). Everythings good there.

Distributor is in the right position.

I sprayed a little carb cleaner in the idle circuit screw holes, and then put the screws back in. I tried turning out the screws while it was running, with no change until it died.

[swamp rat]

Well, i'm still thinking carburation, when you shot the carb cleaner into the fuel screw port the path it goes from there has 2 directions at that point, one is a passage back into the float bowl, the other is the port into the throttle body, its difficult to say wether what you did would blow out any obstruction, i have found the best way to check is to shoot the carb cleaner in from inside the carb and watch to make sure it comes out that little port. the best way would be to pull the top of the carb off and also maybe to be on the safe side pull it and put it on a work bench just in case some small little item decides to fly down the venturi.. I know it sucks..

What did you gap your plugs at? .035? may also help to open that up to about .045 or even .060 if the mfgr of the hei states so.

EDIT: What i'm trying to say above is you need to see the carb cleaner come out both inside the float bowl as well as be able to see it squirt out of the low speed circut into the venturi. Your call if you want to pull the top of the carb off while on the engine, i have done it in the past, ya just got to be really carfull with screws, jets and metering rods ect...

I just pulled out my edelbrock manual and checked ther troubleshooting section, it aside from everything i covered said to check for air leaks on both the carb gasket and intake gaskets as well. so go ahead and fire it up, then give the gaskets little short shots of wd-40 or even carb cleaner, one shot then wait and listen for the engine to speed up, if not another shot in a different place ect untill you rule out the gaskets.

[Ackattack]

Yeah, I squirted the carb cleaner through the screw holes in hopes of doing something. Looks Like I'll be pulling the carb off and cleaning it up. Will also double check the float dimension and linkage (I remember when I rebuilt it I had to bend one of the linkage rods......so I'll double check those)

[Jacfourteen]

I think that cleaning the carb is the next logical step, you've pretty much covered everything else. Hope it works!

[gkesseru]

I have an old stethoscope that I use to listen for vacuum leaks. I put a long 1/4" tube on the end and point it around the carb base and intake edges. It will pick up any vacuum leak as an air whistle.

[Zeke's Garage]

How confident are you in the condition of the cam? I had one going flat, and couldn't for the life of me get the idle mixture set right or get any consistency out of the idle.

[Sinister]

When I swapped intakes, my timing was severely retarded and I could not get it to idle to save my life. I advanced the timing a bunch, got it to idle, then set the timing.

[Ackattack]

So I removed the carb tonight. I took off the top, and in the fuel bowls there was a gel like substance. I have no idea what the heck it could be. It was literally like a clearish white gel. So I cleaned that out of the bowls, sprayed carb cleaner through the idle circuit and all the jets and what not to get it cleaned up. So I think that was the problem. So that's good.

However, somehow when I disassembled the carb, one of the linkages got up and walked away. I even had a little magnetic bowl I was putting stuff in. I looked for about an hour for the stupid thing, I couldn't find it....so I'll order a new linkage set ($20 down the drain for a stupid little metal rod)

The second thing....what the heck is this gel stuff?!? What it really reminds me of is this spray on gasket remover stuff....but I haven't used that stuff in about 8 years! My only thought is that I sucked up some type of crap from the fuel tank....maybe water...would it turn to a gel like substance? My tank is nearly empty. I don't have any other ideas.

So hopefully I'll get some a new linkage tomorrow, get some gas, install a new fuel filter while I'm at it, flush out the fuel line, and put the carb on and everything will be good.

[swamp rat]

Arrrrhhhhh!!! I hate it when that crap happens! ya know when you reinstall the carb and its all done your gonna find it! Good thing ya lost it while on the bench!

I think the white stuff is just from old gas and water from condensation from sitting around, its good for cloging jets.

Did ya pull the main jets out and clean them and the pasages too? Just checkin..

[Ackattack]

I didn't pull them out, just shot carb cleaner though them.....I "wanted" it to be a quick easy night....until I lost the little linkage..grrrrr

[Jacfourteen]

That sucks about the missing piece, cleaning out the "gel" will help things out quite a bit. My son's quad was running rough and it has a similar substance with some white oxidation in the bowl and after I cleaned it it ran much better. Let us know how it turns out.

[Ackattack]

got the linkage today, put the carb back on and no change

So I got a rebuild kit, and hopefully I'll get it rebuilt tomorrow.

[my67c20]

How long was it sitting while you were regasketing it? Sounds like you could have some bad gas. Try running it off a gas can with some fresh fuel. Reverify tdc. Find someone that you can swap the carb out with, then at least you can tell if its engine or carb. Another trick is to spray carb cleaner around the intake while it is running. If the engine rpm's go up you just found your vacumm leak. Have you put a vacumm guage on it and tried to tune the carb that way. Sounds like you could be chasing a few things. Need to narrow it down.

[Ackattack]

SUCCESS!!!!

Rebuilt the carb and it idles and drives great. I didn't do a highway drive, but down the driveway about 20mph it was good. Also got on it a little, and sure enough it has a posi in it

Thanks for all the help and running through possibilities to check.

[swamp rat]

Good news!!!