Carb help desperation....need suggestions

[Accordngs]

Let me begin by letting everyone know that I know very little about carbs...

My setup: Stock 289, MSD Ignition, Edelbrock Intake Manifold, Edelbrock 650CFM carb with electronic choke.

So last week I decide to replace my stock manifold and carb with the edelbrock setup...

I install it. Start it up. Seems to run fine, but I notice a coolant leak from the manifold. So I do another tear down to put more liquid gasket down. Reinstall all the parts again. Coolant leak fixed, but now the car won't run for crap.

Had difficulty getting it to start. Can only get it to start when physically holding closed the choke. After letting it warm up I tried adjusting the idle screw, the timing and what not. No luck.

Engine is surging, dying without the choke. When it does idle it seems rough. The timing looks to be an entire cylinder off but when I adjust the dizzy to get it close to the mark the engine dies.

My head is spinning at this point and getting a bit frustrated. Figured I would post here for some insight because it always ends up being something easy that is right in front of my face.

Thanks guys!

 

[bax]

The fact that you have to the choke shut means it needs a richer mixture to run. Lots of ways to be too lean. my first guess would be a vacuum leak. a large one.

Did you remove the distributor when you changed the intake? If not timing should not be an issue. if you did it could be an issue.

 

[lasadoor]

double check all the gaskets on carb, spacer, and intake mating surfaces for leaks. is it possible when you laid more gasket sealer you covered a port?

 

[arffbronco]

Edelbrock 650 sounds a little big on a stock 289 or 302. Usually that motor doesnt need anything bigger than a 500 CFM. Sounds like a possible vacuum leak and possibly over-carbed

 

[71broncman]

Dizzy's probably off by a tooth. Doubt it's the carb if it seemed to be running fine before. Or it could be the wires are off by 1 cylinder on the cap. How do the plugs look?
Mark.

 

[John Marinan]

Check the return spring on the carb.

 

[Accordngs]

The fact that you have to the choke shut means it needs a richer mixture to run. Lots of ways to be too lean. my first guess would be a vacuum leak. a large one.

Did you remove the distributor when you changed the intake? If not timing should not be an issue. if you did it could be an issue.

I did take out the distributor.

I tried to get the motor to TDC after having this issue. Due to the fan I have trouble getting a ratchet in there to turn the motor...so I bumped the starter until it got about there. Still doesn't seem right though.

double check all the gaskets on carb, spacer, and intake mating surfaces for leaks. is it possible when you laid more gasket sealer you covered a port?

I didn't put any gasket sealer on the surface for carb-to-manifold. Only on manifold-to-head where coolant flows. But could still def. be a vacuum leak on the carb.

Edelbrock 650 sounds a little big on a stock 289 or 302. Usually that motor doesnt need anything bigger than a 500 CFM. Sounds like a possible vacuum leak and possibly over-carbed

I used to run the 600 with no problems. And since this thing ran like a charm before taking everything off again I am doubting it is over carbed. Def looking into the vacuum leak issue now.

Dizzy's probably off by a tooth. Doubt it's the carb if it seemed to be running fine before. Or it could be the wires are off by 1 cylinder on the cap. How do the plugs look?
Mark.

The wires and plugs are new. They all look good. I double checked the wires location on the cap and they are all good. I have a terrible feeling in my gut about being off by one tooth. I can't seem to ever get it right where it should be.

Check the return spring on the carb.

Getting a new one at the parts store tonight!


Thanks guys for the input. I am going to test the vacuum leak issue and see if that is indeed it. I will report back. Let me know if anyone else has any other ideas.

 

[SDlivin]

X2 on the timing because of the distributor being off.
You have a timing light? Vacuum Gauge? Both could be useful.

 

[broncnaz]

My vote is for vacuum leak timing being off is no big deal unless you can no longer adjust the dizzy due to the vacuum advance hitting.
While you may have fixed the coolent leak you probably created a vacuum leak in the process. Gasket probably slipped. Many times internal vacuum leaks occur and are hard to pinpoint. I would double check the torque on the intake and if no other vacuum leaks are found I would pull the manifold and put in new gaskets.

 

[Accordngs]

X2 on the timing because of the distributor being off.
You have a timing light? Vacuum Gauge? Both could be useful.

Yea, I have the timing light. That is how I know it is off. Still gotta get to the vacuum issue though.

My vote is for vacuum leak timing being off is no big deal unless you can no longer adjust the dizzy due to the vacuum advance hitting.
While you may have fixed the coolent leak you probably created a vacuum leak in the process. Gasket probably slipped. Many times internal vacuum leaks occur and are hard to pinpoint. I would double check the torque on the intake and if no other vacuum leaks are found I would pull the manifold and put in new gaskets.

I have the MSD ignition and dizzy. No vacuum advance. I am able to spin it a full 360 if need be. But whenever I have the light on it and turn it so that the mark correctly lines up with the pointer....engine starts dying out.

I am hoping it is a vacuum leak. I went tonight and got a new Carb-to-Manifold gasket. I will pull it off tomorrow, replace that gasket. And hope that does it.

 

[lasadoor]

you can use a little 3in1 oil to track down any vacuum leaks on the carb and manifold.

 

[SDlivin]

you can use a little 3in1 oil to track down any vacuum leaks on the carb and manifold.

Or carb cleaner spray, just spray it around the seals of the intake, carb etc... if the idle goes up temporarily then you know there is a leak.

Others will chime in, but I believe you should be running around 10-12 degrees advance for your timing.

I have a vacuum gauge if you want/need to borrow one. makes solving vacuum problems a big help, or you can pick up at your local kragen/oreilly's.

 

[brewchief]

Timing 180 degrees out? How much did you bump the starter?

 

[bblue]

I would do the carb cleaner trick to check for vac. leaks where the intake seals to the heads.

 

[austinbrose]

I vote vacuum leak. I just replaced my intake and carb and started but would barely run unless I pumped it a lot. Turns out I forgot a plug in the manifold, put the plug in and it runs like a champ. You probably need a new gasket set, and you shouldn't really need any sealer except on the end gaskets on engine side and on top of them where they meet other gaskets.

 

[broncnaz]

Carb cleaner trick only works on external leaks. if the vacuum leak is internal it will never work.

 

[Accordngs]

Well, replaced the carb-to-manifold gasket --- didn't fix the problem.

Can't even get it running long enough to do any of the test for vacuum leaks. But the more I am dealing with it the more I am starting to think it is a timing issue.

I set the engine to TDC again (at least what I believe was TDC) and re-poked the dizzy. Still no go.

I only put the gasket sealer around the 4 points where the two sets of gaskets meet, as well as around the water channel ports.

 

[SDlivin]

Well, replaced the carb-to-manifold gasket --- didn't fix the problem.

Can't even get it running long enough to do any of the test for vacuum leaks. But the more I am dealing with it the more I am starting to think it is a timing issue.

I set the engine to TDC again (at least what I believe was TDC) and re-poked the dizzy. Still no go.

I only put the gasket sealer around the 4 points where the two sets of gaskets meet, as well as around the water channel ports.

You said carb to manifold gasket, but you meant intake manifold to heads right?
1/4" bead of gasket sealer on front and rear of block (overlapping ends by heads) where the intake manifold sits and some around the water jacket ports that should be about it... and torque manifold appropriately.

I think it still is a timing issue as well, but....

How are you checking for TDC?

 

[Accordngs]

You said carb to manifold gasket, but you meant intake manifold to heads right?
1/4" bead of gasket sealer on front and rear of block (overlapping ends by heads) where the intake manifold sits and some around the water jacket ports that should be about it... and torque manifold appropriately.

I think it still is a timing issue as well, but....

How are you checking for TDC?

Sorry, I kinda jumbled the 2 together...long day.

But yea --- replaced carb-to-mani
Used sealant on mani-to-head in the 4 corners and water ports..then torqued in steps and sequence

For TDC I am spinning the motor by the crank pulley. The balancer has the TDC marks on it that tell me where to go...I even put my finger in the #1 cylinder to try and make sure it was on the compression stroke, not the exhaust. After getting that I then stuck the dizzy aimed at #1. No luck still...tried pulling it and going 180 just for sh*ts and giggles. No luck still.

Def running out of ideas

 

[broncnaz]

If it was a timing issue you would have only needed to turn the dizzy to get it running good. unless your firing order got messed up I still say its a internal vacuum leak intake gaskets can and do slip during install. sometimes they even tear due to movement.
Your earlier statement about it running with the choke plate closed tells me nothing but vacuum leak.