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Old 02-05-2006, 10:23 AM
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rough running, good idle...

Ok I have a fully stock 77 Camaro. It has a 305 and it is giving me some trouble...
I just passed emissions with 0.2 carbon monoxide and 228 hydrocarbons. I just did a tune up, and set the timing to the stock 8 degrees BTDC. Now I have trouble when I first drive it in the morning. It will give me trouble with acceleration unless I tap the gas, and will die when I stop unless I tap the gas. It does it only when my car is driven the first time in the day. No matter what the temp is the car acts like it is going to die. The only way to remidy it is to stop after it warms up turn the car off, wait a minute and start it again. I thought it might be the choke, because for some reason the spring wont allow full movement of my choke plate so I leave it too far open for starting conditions, but it starts fine and runs fine as long as I tap the gas at acceleration, at stopping ans at putting the car from park into gear. I just cleaned some of the spark plugs it got dark before I had a chance to do them all, and I don't have a garage. My plugs and wires have less than 9,000 miles on them anyways. They weren't fowled up with oil, but they looked like they had been sparking too hot, they looked a little red and there was a hardened crust on them that was the redish color. This is all that I can think of excet that whe I tune the carb the idle mixtures are normally about two or two and a half turns out. The other thing is I think the jets in the carb might be for a 350 it is a richmand 2 barrel. PLease give me all the help you can. Thanks.

Oh yeah another symptom. While I am driveing if I don't stomp the gas enough it sounds like it is dieseling. So I have a feeling the problem has to do with the ignition, and the advancement. One last thing was that I have a port vacuum switch for changing the vacuum at different temps from manifold to port vacuum to control the advance. But the switch is bad and I bought a new one but I can't get the old one out of the gooseneck. When I really crank on the switch it warps the goose neck to where it leaks anti-freeze. So these are just a few more things that I remembered.
John

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Old 02-05-2006, 07:36 PM
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........

does no one know, is does no one want to answer...
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Old 02-05-2006, 08:24 PM
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Doc here,

I'll try to help ya out..

First, It sounds like the Carb is in conflict with a mechanical detent and a vacuum assisted linkage..(like Choke Vs secondary pull off or the like) and it stays that way until you shut the car off, relieving the vacuum , and heat soaking the engine, (allowing for instance , the Choke pull off to drop into place because it is thermally open)

Is this a Quadra Jet? Without knowing the Carb you have it's hard to predict..but this is what it in general sounds like to me..

The plug color is Normal..Brown rusty red is just fine..Black sooty is rich..White with metallic specks is too lean/w detonation. jet black and sticky is oil fouling..

If when you romp on it, and it sounds like a can full of marbles, It's detonating, No advance..or bad / Low octane fuel..If the TVS is bad and you can't replace it, move the advance hose over to a manifold source for now..until you can repair the TVS. Detonating will tear up your Engine!

As far as the TVS, have you tried heating it up with a propane torch while trying to turn it? That should help get it out..

Hope that helps you out..

Doc
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Old 02-05-2006, 10:49 PM
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thanks...

well a lot of that makes sense, but I don't quite understand what you mean about the detent...
The carb is a rochester, I don't remember if I put this but it is off a 350, and I have a 305 (don't know if that matters much). Right now I have the advance on a port vacuum, I thought the advance on manifold would only advance the car while idleing, and port would help when reving the engine...
The choke has been the only thing I could think of, but I can't find a replacement, I was going to check Merle's but I haven't had time to drive down there, they were the place I got the port vacuum switch from.
As far as heating the switch while twisting, no I have not, I don't know why I hadn't thought of that, thank you, it's kind of late so I'll have to try that tomorrow, but I appreciate your help very much...
If anything I said is false or doesn't make sense give me another ring...
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Old 02-06-2006, 12:05 AM
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Doc here,

The Detent, Is a Tear drop sort of shaped mechanical linkage part, may have little steps in it for other linkage pieces to sit on, If you look around the outside of the carb, you'll see what I'm talking about..

As far as replacing the whole choke that may not be necessary, but if you do..get an electric one..you'll never regret it..and if you do, post it here, and I'll tell ya how to hook it up.

Solid manifold vacuum for now won't hurt a thing , except maybe raise the idle a bit..but running with detonation, can damage pistons, valves, gaskets , It's really hard on the engine..

Good luck with the TVS , hope that works out for you, It should..

350 and 305 carbs make no difference they are interchangeable with few exceptions.

Keep us posted!

Doc
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Old 02-06-2006, 06:44 PM
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well.....

Doc... I am sorry but I can not find the detent.... I have a list of things that I may have different names for, of what comes out of my carb....
Obviously the port and manifold vacuum inlets...
The air conditioning solenoid...
The vacuum break valve (for the choke)
The throttle linkage...
The choke linkage to the step plates...
The vacuum port for the break booster...
The transmission detent cable...
and besides that I can't find any other type of detent, maybe I called it something else...
I don't mean to monopolize your time, but I just don't know. What I do know is that the carb is a rochester 2-GV. I had replied on another forum about my float issues and maybe you can give me an opinion, but on this particular model, I am not able to ajust the float level to any specification due to its design.
As the float sits now is how it was adjusted in the rebuild packet... Is it possible that the problems I have could be because of this...?
I went to a rochester site (un-official) and some troubleshooting guides said that it might be the problem...
But the real problem is how to adjust it. If you don't know the inner buildup of these 2-GV's hit me up again, and maybe we can figure it out together...
John
And thanks for all your help...
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Old 02-06-2006, 07:39 PM
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Doc here,

OK, miscommunication here..

They call it a "CAM" I 've always called it a detent..at anyrate..sorry about that..The drawing shows what I referring too, It's a bad reproduction, hope you can read it, but anyway the red text shows the linkage pieces I'm talking about..

These lock into each other, and some have "notches" for different settings throughout different heat/Vacuum ranges..If you had one working against the other after warm up, until the engine shut down (No Vacuum) And the engine heat soaked (Temp went up) allowing the pieces to fall away from each other, (normal on warm engine, would run bad on warm and binding..)

It's hard to put into text, you have to keep this in mind and look at the carb move the linkages while you do and you should follow what I'm saying...

Also, You should be able to find a bendable tang on the float where the needle seat sits on it.. Bending it up will DECREASE the bowl level..Bending it down will INCREASE the bowl level..

If I understand what you are saying correctly, They told you this is NOT an option? Never heard of it, but I don't work with 2 BBLs that often either..Maybe pull the airhorn, and take a look..If it is there, bend it the way you think it needs to go..If not, DON"T bend the arms..

What I'd do is look for an aftermarket float that DOES have an adjustable tang on it...that will work on that carb..



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Old 02-06-2006, 09:09 PM
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ok...

now I know what you are talking about, but how can I fix it, do I just luge it with some grease or do I need to find replacements...?
As far as the float goes I must have also miscomunicated...
It is an option to adjust but I can't see how it is possible to check the level... I'll try to send the pic back on this thread if I can't then... well I'll have to e-mail it to you... but if you look where I circled you can see that the entire float assembly is attached to the top portion of the float bowl, and the only way I know to adjust is by spaceing from the upper lip of the lower float bowl...
Is there another way to check float level?
Because if you look it is upside down from any other carb I have worked on, the seat and float dangle from the upper float bowl portion of the carb, I don't get it...
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Old 02-06-2006, 09:53 PM
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Leave the floats alone.

Just squirt some WD-40 on both sides of the carb linkage to see if that frees it up.

Doc's a knowledgeable mechanic and I think he's a little over your head. I know he's over mine.
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Old 02-06-2006, 10:59 PM
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ok... but I understand...

Quote:
Originally Posted by 57 Chevy
Leave the floats alone.

Just squirt some WD-40 on both sides of the carb linkage to see if that frees it up.

Doc's a knowledgeable mechanic and I think he's a little over your head. I know he's over mine.
Well I agree e's smart, but when it comes to carbs I can understand what he means now... but the float and the linkages are two different topics...


Anyways Doc...
I checked my cams and they all seem to be really loose, when I got the carb I did a full restore, but I have seen wierder things than a gam stick...
Then I checked my float, I figured out a way (I think, to adjust it, but I had no specs so I just made it level with the float bowl... which is something I heard was a common way to adjust, I adjusted my accelerator pump in also, because it seems like sometimes I get flooded when I step on the gas in the mornings....
Lastly I tried putting the advance on manifold, it allowed for 21 degree increase off my 8 degree original advance, but once I started going somewhere it seemed as though the slurry noise only got worse...
I don't think that I am getting detination as you think I am, I possibly am just not getting my quench area fully combusted before the piston goes back down... but I don't know...
Oh yeah, I also checked the fuel pump and I am getting 6 PSI so I think I am ok there, I might have the problem under control, but I wont know until I check on it in the morning... Normally the car will do ok all day once it has been around for a while...
Thank you again for all your help, and if this doesn't do the trick can you think of other things that I could do or maybe just go back to that site where you found the diagram and help me out with some float specs...
Thanks again
John


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Old 02-07-2006, 07:27 PM
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Bump

Bump........
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Old 02-07-2006, 08:43 PM
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Doc here ,

In the kit you got, It should have included a cardboard measuring tool that slides between the air horn and the float..It should have several measurements on it.

Find that and get your instruction sheet, follow the procedures for sliding the measuring tool in and the Highest/lowest allowable distance.

IF you lost that tool, or tossed it you can use the Spec sheet which will have the measurements on it, and a steel pocket ruler..

If you lost the spec sheet, you'll need to get a manual for your car, and look it up there.

Just being level may not be enough fuel for that carb. It may be starving a bit..Doesen't the engine sit on a 2 to 3 degree up angle? That alone could be a problem.

Sounds like the fuel pressure is good.

The timing sounds Wrong, and I think you are over-advanced a bit. Pull and plug the vacuum advance and hook up your timing light.

At 650 RPMS Manual, Or 950 RPMS automatic Trans, fully warm, choke wide open, Detents slipped (rev it to be sure your not on a high or medium idle detent) but at curb idle, Set your static timing for 8 degrees .

Hook the vacuum back up, and take a ride , hammer it on the freeway on ramp 0 to WOT ..It should not sound like a Can full of Marbles, then find a STEEP hill, get in the highest gear you can, and lug it up the hill, at the point of almost stalling, it should not sound like a Can of Marbles..If it does, It's still too far advanced, or you need octane boost.

As far as the linkages being free and movable , you have to inspect this DEAD cold, (where your having a problem, ) remember, after it warms and is shut down, It works fine for the day..and one could be in the wrong position in relationship to the other, the cams (detents) with the locking step pieces may be binding on a cold start, (Cam to Cam) so you have to be sure your EXACTLY the way the drawing shows.

Doc
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Old 02-08-2006, 02:47 PM
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ok..

I have checked and in the morning everything seems to be better, but now the can of marbles is still going on. I have pull the dist cap and checked the mechanical advance, seems to be up to snuff, I set (at curb Idle) the timing at 8 degrees and it still does the same thing. The problem is it isn't over advancing, I hooked up my vac gage and it says that I have late ign timing... I'm starting to think I may have a vac leak somewhere, but that wouldn't explain the high rpm marbles... I'm going to try and tinker around with it some more, thanks for all the help...
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Old 02-08-2006, 03:05 PM
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Doc here,

I didn't mention it before because you said you Just passed smog with good numbers, But is this an Air Injector Reactor Vehicle? With an EGR valve?

If so the EGR may have a big azzed hole in the diaphram..Start the car, get out a hand vacuum pump (or use a manifold source vacuum) and put it on the EGR vacuum port..The valve SHOULD open, and the Engine should die..

If the Valve does nothing, and it just speeds up a bit .. the diaphragm has a hole in it, If the Diaphragm pulls, but the Car does not react (It should Die right off at idle) then the internal shaft of the EGR is busted or leaking..replace the Valve..

This will cause detonation, bad vacuum numbers, and some of the other stuff you described.

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Old 02-08-2006, 03:58 PM
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uh....

Well the EGR is new within 2 years... but I'll check if I remember right it might be too small to put my finger in but like I said I'll check, and just so you know, I had a guy service it when I was more of a lamen and he put a bb in the vacuum line because he said cars run like **** when it is always on, maybe my car is running too rich at high rpms and is combusting early...?
Tell me what you think, I'm going out right now to do a cyl balance test.
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