Won't idle.. problem found

[Buldozer]

Yea, the idle mixture screws with it running should kill it. Screw them in until it about dies and when it about dies back them out until it idles... or in your case at least runs....

Sure sounds like you have a messed up carb or a bad vacuum leak and I will wager on the carb unless you have an EGR problem if that engine even has EGR on it... since the engine has not been apart to have the kind of leaks that would normally cause it not to idle...

You can always just go to the parts store and pick up a carb and see if thats the problem.... or swap one from another rig

 

[browngr5]

So here's what I have. There's a large vacuum line going from the valve cover to the base of the carb. There's a line going from a port on the intake manifold to a distribution thingy wity two lines coming off of it. One goes to the passenger side of the carb and the other is capped, which presumably went to the dizzy at some point. The PCV plug going into the valve cover does not have a good seal on it.

Is that one of those vacuum ported carb spacers on an EGR style manifold?
Check the intake gasket to see if its burned a hole between intake and spacer. I had this problem last week. I switched to an intake that was pre-EGR.

Some intake manifolds had a EGR passage that recirculates exhaust through a port on top of the intake. Worked fine when you have an EGR plate. Someone may have pulled it off and set a spacer with a vacuum port in it's place. It slowly burns a hole in the gasket and runs like crap.

 

[Nightstick]

Is that one of those vacuum ported carb spacers on an EGR style manifold?
Check the intake gasket to see if its burned a hole between intake and spacer. I had this problem last week. I switched to an intake that was pre-EGR.

Some intake manifolds had a EGR passage that recirculates exhaust through a port on top of the intake. Worked fine when you have an EGR plate. Someone may have pulled it off and set a spacer with a vacuum port in it's place. It slowly burns a hole in the gasket and runs like crap.

I can't tell you whether or not it's an egr style manifold. I spoke with BanjerPicker about it last night, and he had the same problem a while back, with the gasket you mentioned being the problem as well. Since it seems this problem has gotten progressively worse, not just an all of the sudden thing, I think that points to a gasket or vacuum line being the problem. If I have time, I'll check it this evening. I'm also going to remove the vacuum distribution thingy and cap that port on the manifold since it serves no purpose.

 

[Chief Master Sergeant]

Vacuum leak at the manifold??? Sounds like what mine did in Alaska.

 

[Nightstick]

Back on it... I replaced the gasket on both sides of the carb spacer, and the vacuum advance line, no change.

I turned up the idle screw enough so I could make it from the drivers seat to the engine compartment before it died, and started messing with timing. Unfortunately, my timing light it at a buddy's house, so I just turned the dizzy to see if things would even out. When I turned it counterclockwise, it seemed to run worse, so I turned it clockwise and it wanted to stay running without feathering the gas. I dialed down the idle screw and it stays running at lower rpms. It's up to temp at this point, so I don't know how's it going to act when it's cold, but I think I'm on the right track at least.

Only problem is its fluctuating a little, and not just maintaining a smooth idle.

 

[Nightstick]

Well, I let it cool, and it's doing the same thing as before. No idle. Hmmmm

 

[Nightstick]

Replaced the coil, no change. Screwed the idle mixture screws all the way in, no change.

What are the chances that the fuel pump (mechanical) could be bad? If it is, would it still be able to pump at higher rpm, but not lower?

 

[Nightstick]

Vacuum leak at the manifold??? Sounds like what mine did in Alaska.

Chuck, are you talking about the intake manifold gasket, or the carb gaskets?

 

[Buldozer]

Screwed the idle mixture screws all the way in, no change.

Ok if it still runs with the idle screws both all the way in you have a massive vacuum leak or a carb that is assembled wrong

Time to swap another carb on there and see if your problem does not go away IMO

 

[Nightstick]

Ok if it still runs with the idle screws both all the way in you have a massive vacuum leak or a carb that is assembled wrong

Time to swap another carb on there and see if your problem does not go away IMO

It wouldn't run with the idle mixture screws in.

I believe I figured out the problem. I picked up another timing light and a vacuum pressure gauge today. The pressure was reading a little low, but it was also very jumpy, which I'm old means that the timing is off.

I threw the timing light on it and it was about 35* BDC at an RPM in the normal idle range. I pulled the dizzy and was in the process of stabbing it but the oil pump rod was giving me fits so I mowed the grass instead of continuing to get frustrated. I'm off again on tuesday, so I'll get to it then.

 

[Buldozer]

Yea, that a lot too early for sure What problem was the oil pump drive shaft giving you? You might want to hook that vacuum advance back up too

 

[Nightstick]

Yea, that a lot too early for sure What problem was the oil pump drive shaft giving you? You might want to hook that vacuum advance back up too

The shaft is leaning over to the side down in there preventing the dizzy from going all the way back in. I need a tool to pull it all the way out

 

[Buldozer]

And maybe a clip to hold it in the distributor to so it does not end up in the oil pan! I have avoided that over the years but narrowly a couple times. Stop by harbor freight and get you a set of forceps or long needle nose and snatch it out... you may never use them again so no need to pay top dollar for them. I have a pair if you don't get it going before OCBR but I know you will!

 

[Nightstick]

And maybe a clip to hold it in the distributor to so it does not end up in the oil pan! I have avoided that over the years but narrowly a couple times. Stop by harbor freight and get you a set of forceps or long needle nose and snatch it out... you may never use them again so no need to pay top dollar for them. I have a pair if you don't get it going before OCBR but I know you will!

Lol, thank man, good advice. Come hell or high water I'll have it going by then!

 

[blubuckaroo]

The shaft is leaning over to the side down in there preventing the dizzy from going all the way back in. I need a tool to pull it all the way out

oil pump shaft has a taper at the end to help it to go into the distributor. The shaft leaning over a bit shouldn't be a problem. I usually press down on the distributor while bumping it over with the starter. It will align the shaft with the distributor and drop right in.

 

[Buldozer]

Yea I usually put a rotor button on to so I can rotate the rotor back and forth if I need to to better align it also. That way I can see exactly which wire I will lign up with

 

[Nightstick]

Found the problem, and I need a part.

Not knowing that the 2150 has a different footprint than the 2bbl that came on the 69s, I was using the incorrect spacer and gaskets. As you can see in the pic, this created a big hole on the back side of the carb sucking in air. So, I'm done banging my head against the wall, but I'm in need of a PCV spacer for the 2150. If you have one to sell, hit me up please.

 

[Justafordguy]

That would certainly make it run bad.

Not sure if you can still buy the spacer new but I'm sure you can get the right gasket, just get one for a 77.

 

[Nightstick]

Thanks to BanjerPicker, I got the correct spacer and gaskets. I'm actually using an EGR spacer with a block - off plate. Only had to grind off some of the underside of the egr portion to get it to sit flush on the intake. Fires right up and idles great.

 

[bax]

I bet you had a vacuum leak.