Starting problems - all of the sudden

[THE73Z]

I'm used to American V8s and I'm still not very familliar with this engine, but here's what I have.

Stock rebuilt 73 2.4L with 72 SU's and stock air cleaner (which I assume matches the carbs since the car came with the original carbs and another air cleaner).

The problem; all of the sudden the car has difficulty starting. It sputters, backfires, gets up to speed then chokes and wants to die. It basically doesn't sound like it's getting enough fuel or air. Once it's warmed up it runs fine. However the idle seems a little rougher and slightly slower than I remember. All summer it just purred like a kitten.

Where should I start? The flap on the air cleaner is in the open position, should I close it? The temp is about 65 here. I don't know anything about the mechanical choke -- other than it must restrict airflow causing the engine to run richer and therefore faster. The problem is the same with and without use of the choke. I may try some carb cleaner - though I don't think that's the problem. The carbs had sufficient oil the last time I checked. Or am I totally off, and I should be checking ignition?

Thank you for your input, Z

[MikeW]

The temp is about 65 here. I don't know anything about the mechanical choke -- other than it must restrict airflow causing the engine to run richer and therefore faster. The problem is the same with and without use of the choke.

It sounds very much choke-related to me. Cooler temperatures certainly have this effect. I would first verify that pulling the choke handle back all the way actually actuates the chokes on both carbs.

[59ghia]

Could be getting to much fuel, with the choke in the full down position, engine not running, put your hand under the carb, and see if the nozzel is still pulled down, try pushing it up. Mine on rare ocassion will hang up. I pull the choke handle up and down a few times, and I'm good to go.Also check points, cap and rotor on ignition side. Last tune up?

Good luck

Dave

[andrewg3300]

my 73 did the same thing and i adjusted the choke cables. only one carb was getting choked. still hangs up now and then.

[beandip]

It does sound like a choke problem. being that you said you are unfalmilar with the car. with the engine off , pull the choke lever back and then shove it to the off position. Now go and reach under the carberaters and feel for the little hose that runs from the float bowl to the carb adjustment knob. Not see if the knob will snap up when you push on it. the same with both carbs. This '' knob '' is the mixture adjustment and is the bottom of the nozzle . If the nozzle is sticking down at all it is causing a vary rich mixture . The fix if this is happening could be a couple of things. One is if the little hose is stiff or brittle from the heat . this will cause the nozzle to bind and stick . Another thing is the nozzle could be covered with crud . If you remove the nozzle and clean it with 1500 grit wet dry sand paper using a little oil on the paper and burnishing the nozzle from in to end ,NOT AROUND THE CYLINDER , then coat it with some NEVER SEIZE and reinstall it . If you look you will see that there is a small linkage connecting the nozzle to the upper part of the carb. you can carefully remove the tiny cotter pin and the nozzle will drop down. Remove the hose first and catch the fuel that runs out , a rag will do. Do the cleanning and replace it. If when you first check the nozzle and find it sticking and the hose is not stiff , try and put a little twist in the hose . Some times this will do it. Gary

[beandip]

I am assuming that you have round top SUs not flat tops.

[Sean240Z]

One other thing to check is that you actually have a "choke cable" and not a "bicycle brake type cable". When I bought my car, the previous owner had relocated the choke lever to under the dash and replaced the cable with, what I assume was a bicycle brake cable. The old cable did a good job of pulling the choke open, but did a really poor job of pushing the choke closed.

After my car was warmed up, I had to stop the car, open the hood, jump out, push each of the chokes closed, close the hood, jump in the car and proceed. It really sucked when it was raining!

When I had my new motor installed, I installed an OEM choke cable and the problem was solved. Just one more thing to look for.

Cheers,

[mlc240z]

never thought about using anti-seize compound. i used a light coating of white lithium grease. any advantages to anti-seize?