stix

I have a 1969 Cutlass with the 350, 2bbl. If I let the car set for more than 10 days or so, it will not start. I have to prime the carb to get it to start. My mechanic said it might be the diaphragm in the fuel pump, it is a new pump but it could still be bad, he also said it could be the carburetor because I have an air leak in the carb somewhere because if I put my hand over the intake of the carb, choke it, it will still run. So im wondering if I should just fix or replace the carb first or go ahead and replace the fuel pump. Thanks

oldcutlass

How long are you cranking the engine to get fuel into the bowl? I would definitely look into your vacuum leak if you can't choke the engine with your hand.

RetroRanger

I think the fuel pump has a weep hole in it. If the diaphagm gives up, fuel comes out the hole, at least thats what happened to me last week.

when my car sits a day or two i set the choke turn the key and crank for 3-4 seconds, then stop crank8ng and shut off the key. Then i pump the gas and typically it will start. If it sits longer say 10 days or more same scenario except it may take 4-5 iterations of the crank pump crank to start.

as eric said if you have a leak fixit. Also does your choke work?

no1oldsfan

Sounds like a carburetor issue to me.

stix

I do have the choke dialed in so its working properly. Stomp the pedal to close the butterfly, it works, then as the car heats up the choke slowly opens. Unless I hit pedal again to engage the choke pull off

no1oldsfan

My 66 has the same issue. I haven't had the time to rebuild the carb.
Like RetroRanger asked. Does your choke work? Oops I was late on that.

stix

Probably 10 second cranking intervals. Ill check all my vacuum hoses, good call. thanks!

stix

The carburetor has been rebuilt but i guess it still could have an issue, Ill check all my vacuum hoses first to see if maybe I have a bad hose or maybe that green sensor(that has 2 vacuum hoses going to it) inside the air cleaner housing might be leaking

stix

Quick update. So my "mechanic/shop owner" told me that he could'nt choke out the engine by covering up the carb intake. Well he forgot to tell me that one of his flunkies found the issue and fixed it, it was a bad vacuum hose, but the flunkie never told the owner that the issue was fixed so the owner was under the impression that there was still an issue. So I just assumed that there was still an air leak. Anyhow at this time the engine will now choke out like it should so Im guessing my issue lies in the fuel pump.

joe_padavano

First, after ten days the fuel in the float bowl will have evaporated to a much lower level. Expect to require some amount of cranking to refill the bowl before the car will start. Second, filling the bowl quickly requires a strong fuel pump. If the check valves have deteriorated, pump performance will degrade and it will take MUCH longer to fill the bowl. If there's any question about the fuel pump, install a new one.

BillK

This has been talked to death here and elsewhere. It seem that the fuel with ethanol in it evaporates a lot quicker in anything with a carburetor. My Wifes Riviera and my S-10 are the same way. What I do is get in and crank it for about 10 seconds. Then hit the pedal a couple of times. If it doesnt start repeat. Sometimes takes 2 or 3 times to get fuel up to the carb but they always start. Both vehicles run perfectly and will start fine for the first few days. The fuel pump in my Wife's car is less than 2 years old. S-10 is original from 1984

69CSHC

I had the same issues when I first bought my 69. So much so that the car came with an extra battery and multiple cans of starter fluid...


I would go over everything with a fine tooth comb before spending additional money which may be unnecessary. In my case it was plenty of small issues that needed sorting out. ( someone had put the fuel filter backwards, small gas leaks, cracked caps on carb ports, air/fuel mixture) Tune it by the book and if there is still an issue then I would proceed accordingly.

Once the issues were addressed the only time I need to prime the carb is if and when I run out of gas.

Yes pretty much the same here.

Stix when the issues are sorted out I believe your ride will operate like Retros and mine, etc. Here is an exact run down of how my car starts (I keep a diary).

If I start her every day after an overnight shutdown she needs 0-5 pumps of gas and 2-3 seconds of crank. (While in use throughout a day she will start instantly before the key is fully turned no pedal, during casual errand runs.)

With one day in between starts its 5 pumps on with some light feathering for about 30 seconds. ( I started her this morning, exactly like this. First with 0 pumps and 2-3 seconds of cranking, no start. Then 5 pumps and on after 1 second of cranking ( I timed it just to be precise for this post).

With 2 days in between 2 sets of 5 pumps with 2-3 seconds of cranking after each set may be necessary.

with 3 days in between 3 sets etc. And so forth and so on. ( I've tried 6,7, and 10 pumps at a time and 5 has proven ideal)

I follow the above pattern religiously. It represents well up to a week. She will eventually not need the 5 additional pump's per day of sitting. For example after 2 weeks of sitting she may need 30-40 pumps of gas. So for me its sets of five with minimal cranking in between, till she starts. The most amount of pumps I can find in the diary ( its a loose diary with pages everywhere...) was 45 after she had not run for a month.

P.S When in a garage she can start easier. She can also occasionally start with 0 pumps after sitting for more than a day. And she can get in a mood once in a blue moon after spirited driving etc, where she may need the pedal fully depressed and you hold the crank open till restart. Below freezing temps and she may be on the extreme end of the pattern. In the end the above highly detailed procedure is not infallible but its definitely a fair assessment.

Of note all the above is with a 14 x 3 open air filter.

BillK

You would accomplish the same thing by just cranking the engine for 15-20 seconds to fill the fuel bowl and then pump it a couple of times and it should fire up. Thats what I do with my S-10 and my Wife's car if they sit too long. The on and off crank-pump-crank-pump really does not accomplish anything other than wearing out the ignition switch and the starter solonoid

oldcutlass

Since you seem to have gotten the vac leak fixed. Next determine if there is fuel in the bowl after 15-20 seconds of cranking by looking down into the carb and manually operating the throttle linkage and seeing 2 solid squirts of fuel. If there is fuel then that is not your problem. There is an old saying that most carb problems are ignition related.

stix

I appreciate the help guys and Ill keep this post updated as to what I find