69 L71 just dies after a warm idle

[Chris H.]

Re: 69 L71 just dies after a warm idle

Lawrence, progress! That linkage is only to close the secondaries. Not open them. They are opened using the vacuum secondaries on the other side of the carbs. Any chance you could post a photo of the close linkage?

[Duke W.]

Re: 69 L71 just dies after a warm idle

As stated the front/rear carbs are opened by venturi vacuum applied to the big vacuum pots, and the mechanical linkage is there to close them positively when you lift off the throttle. If you blip the throttle real hard from idle you should be able to see them begin to open.

Found a problem when practicing a PV for a local chapter member. WOT acceleration and induction noise was not up to par. Diagnosis revealed that the front/rear carbs would not open. Turned out the front throttle blades were jammed in the bore, and I finally applied enough force on the closing linkage to open them. Then it accelerated like a L-71 should.

Duke

[Chris H.]

Re: 69 L71 just dies after a warm idle

Lawrence, for reference here are some photos. Chris

[Guest]

Re: 69 L71 just dies after a warm idle

First you have the wrong front fuel Bowl, side plug is the same height as the center Carburetor, front and rear Carburetor bowl are lower then the Center Bowl Carburetor, i would remove the secondary linkage and plug up vacuum port set up your center Carburetor and go for a 10 mile road test and see what happen if it still stall or won,t start you may have a floating problem ,check your float levels and also pull out the needle and seat check for any dirt

[Chris H.]

Re: 69 L71 just dies after a warm idle

Lawrence, this thread has grown multiple branches. Make sure you see the most recent responses.

[Lawrence S.]

Re: 69 L71 just dies after a warm idle

First you have the wrong front fuel Bowl, side plug is the same height as the center Carburetor, front and rear Carburetor bowl are lower then the Center Bowl Carburetor, i would remove the secondary linkage and plug up vacuum port set up your center Carburetor and go for a 10 mile road test and see what happen if it still stall or won,t start you may have a floating problem ,check your float levels and also pull out the needle and seat check for any dirt

I have not posted any photos of my carbs

[Lawrence S.]

Re: 69 L71 just dies after a warm idle

I noticed detonation on last drive. I checked the initial timing it is now 12.5*. I thought that was weird since last time I checked it was 10.3*. But the 10.3* was with the carb linkage not hooked up correctly. I could not get the car to idle down to 750 or 800 RPM's because the linkage was cracking open the secondaries. I am going to reset to 10* and recheck everything. Probably will put in weaker springs to get the curve correct.

[Terry M.]

Re: 69 L71 just dies after a warm idle

Lawrence
The idle and timing settings have to be done with the secondary carburetor linkage in the correct position. You MUST do these adjustments per the Factory Service Manual (FSM). To do otherwise will leave you chasing your tail -- which is sounds like you are close to. Please follow the FSM for success. If you don't have a 1969 FSM invest in one from the NCRS store. You will find that in the long run it is a cheap investment.

[Guest]

Re: 69 L71 just dies after a warm idle

Well i guess Chris Hewitt posted photos of his Tri power Carburetors that i see, thought they were yours Sorry

[Lawrence S.]

Re: 69 L71 just dies after a warm idle

Lawrence
The idle and timing settings have to be done with the secondary carburetor linkage in the correct position. You MUST do these adjustments per the Factory Service Manual (FSM). To do otherwise will leave you chasing your tail -- which is sounds like you are close to. Please follow the FSM for success. If you don't have a 1969 FSM invest in one from the NCRS store. You will find that in the long run it is a cheap investment.

I have one and set the carbs per the manual...as close as possible

[Lawrence S.]

Re: 69 L71 just dies after a warm idle

Well i guess Chris Hewitt posted photos of his Tri power Carburetors that i see, thought they were yours Sorry

No problem

[Lawrence S.]

Re: 69 L71 just dies after a warm idle

Today, I tried several sets of springs of which a few sets physically looked different but the spring tension for a few sets were basically the same. I had the centrifugal coming in very early and had to set the curb idle around 650 rpm so the centrifugal advance would not effect the timing. I did not like that .I wanted the centrifugal stay at 0* at 900 rpm. I put a little stiffer spring in and I basically got the timing set so 36* comes in at 2800 rpm. With a blip of the throttle I can get the timing up to 39*. My initial timing is 10*. Car runs great and thanks for all the help.

[Terry M.]

Re: 69 L71 just dies after a warm idle

I have one and set the carbs per the manual...as close as possible

OK That's the ticket.