HI,

I have a 76 manual with a 1406 Edelbrock carb (PO) which recently developed some interesting but annoying issues.

The symptoms:
1/ when the weather is nice outside and the sun hits the car for a few hours when parked, the engine stalls very shortly after starting up. If it runs, it hesitates quite a lot and if I do not give it some gas, it stalls.

2/ following 1/, if I insist on driving, the engine stalls every time I encounter a situation where I am switching back to neutral or disengaging the clutch or simply do not press the gas pedal.

3/ When the engine is warm, the issue does not appear.

4/ Works fine first thing in the morning (we are still close to water freezing temperature overnight here)


A couple of observations:
1/ After driving, I removed the air filter to check, and the carb smelled a bit of gas.

2/ The problem did not exist before I ran into some fuel leaking issues with my tank fuel lines. They were replaced (and the tank was dropped). The problems appeared 1 week afterwards (60miles). At the same time, the oil pump was replaced for a high pressure one (garage decision).

I am not sure where to start.
My initial suspects are listed bellow, but before I start playing with things that I am not too familiar with, I would rather ask around for some pointers and advice.

List of possible culprit:
The carb is my main suspect.
1/ fast idle set too low?
2/ dirty carb needing to be cleaned?
3/ breakthrough through the fuel filter?

How involving is it to clean the carb out?

I apologize for the long post, any return of experience or advice would be appreciated.

 

1. what is the warm idle speed set to?
2. is the choke properly adjusted?
3. can you adjust the idle mixture screws?

 

1. Part of the issue is that my tach is not working... So I have no feedback on the rpm.
(I should have posted the info in the original post...).
2. The choke was properly adjusted, can it drift/change with time?
3. According to the manual, I should be able to adjust these screws. Same question, can they drift, change with time?

Do people have cold and warm weather settings?

All of this is new to me. I enjoy learning and do not mind getting my hands dirty.

With regards to point 1, do you think that it could be the warm idle and not the cold one which is set too low?

 

I actually found a very nice video for Edelbrock carburators:

I guess I will have to go through all the steps one by one.

Good resource for a newbie like me.

 

Noticed in your avatar that you're "up north". Is there any chance the gas in the car is "winter blend", or old gas from last season?

 

Good question. I have no idea when the blends change. A quick search suggests summer day.
Definitely not old gas from past season, the tank was properly emptied when removed.

If the changeover happened a couple of weks ago, it could be the reason. I will ask at a station, they may know... and in which case, I may need a summer vs winter blend setting on the carb. Interesting...

 

Those carbs are really easy to rebuild. If your half as handy as Red Green you'll have no problem doing it. If I was you search the youtube for a good rebuild video, and have at it.
If thats not going to work for you PM me and I'll do it for you.

 

Thanks, very nice of you. I may take you up on the offer especially if things go wrong
I will give it a try before, as you said, it does not look too difficult.

I may have to create a new post as now the stalling problem happens every time I am not giving the car any gas: slowing down and changing gear etc... It does not matter if the tank is full or almost empty, the weather does not matter anymore etc...

The exhaust fume does not smell right either, it does not have this good smell that you get when everything is running right.

Anyway, first things first: replacing the fuel filter, cleaning the carb and see what happens. Maybe the spark plugs as well (although this seems to be a PITA of a job).

 

Spark plugs are relatively easy compared to newer cars. You will figure out quickly which ones to change from the top and which ones to change from the bottom. Pay attention to the way they look when you take them out. Ideally they should all look about the same, and if they don't make sure you mark down which cylinder the different one(s) came from. That might indicate other issues.

 

you either have to get the tach in the car working or hook up an external tach to check the idle speed setting and to adjust the mixture screws

 

Do you have any recommendations in terms of external tach?

For the moment, it is easy: the car does not idle, just stalls...

 

did you check if the tach wire on the distributor is connected? for external, see what Harbor Freight has

 

If you don't already have a timing light buy one with the tach readout on it. You can use it to set your timing and know where your RPM's are during diagnostics. Not a complete fix, but it might help you in the short run.

 

Tach and timing light added to my wish list then.
I have read a lot of excellent posts on this forum. Lots of good info there.

I decided to tackle the issue yesterday night after realizing that my choke was not closing properly as suggested in the basic setup video I posted above.
There are a lot of things which need to be corrected on that carb and system but closing the choke allowed me to at least get the car running on idle in the garage! Victory!





And what did I see? a massive fuel leak (one more!!!! I already had the hoses from the fuel tank leaking a month ago!) at the filter end!. I replaced all the old porous fuel hoses and could get the car to idle for a few minutes before dying slowly (need to investigate).

At least I have made some progress...

I now have a quite a few questions about fuel filters etc... and will post a new thread about it.

Everybody, thank you for your suggestions and comments, always very much appreciated.

 

Something struck me, as it was being discussed in another thread. Are you stuck with Ethanol laced gas or the non-ethanol? If ethanol, maybe it's eating away are something internal to the carb, like the float or needle and seat (and maybe the filter). Just a thought.............

 

Have you checked/cleaned/replaced the fuel filter in the carb? After working with old fuel lines, "stuff" could have been disloged and gunked-up your fuel filter. Also, if you replaced the rubber "S" hose [from the steel fuel line to the fuel pump] using regular straight hose, it is probably kinked-up and blocking fuel flow. There is a 'molded' hose for that location and it MUST be used, unless you have a way to keep regular hose from kinking.