Random Misfire while cruising

[Mark Maras]

9 minutes ago, jalexquijano said:

From the top lowering the jet to allow more fuel.

 That's what I remembered. We've got to keep this in mind because most of us view (mentally) the m. screws from the bottom. I'm still curious to know if both carbs are pulling the same amount of air at idle.

[jalexquijano]

1 hour ago, Mark Maras said:

 That's what I remembered. We've got to keep this in mind because most of us view (mentally) the m. screws from the bottom. I'm still curious to know if both carbs are pulling the same amount of air at idle.

Well i did balanced both of the carbs with a synchometer and turning the right screw at the linkage. I can try again tomorrow 

[jalexquijano]

7 minutes ago, jalexquijano said:

Well i did balanced both of the carbs with a synchometer and turning the right screw at the linkage after turning the fast idle screw to raise the idle 2500 rpm. When both carbs measured the same i returned the fast idle screw to current idle.  Im i doing something wrong here? Should i disconnect the linkage before doing this? I also have a colortune device. 

 

Edited November 5, 2021 by jalexquijano

[psdenno]

The Colortune will give you a good visual check on what's happening during combustion.  When I used to adjust the carbs, I would follow the steps in the shop manual and then check with the Colortune for any final adjustment.  No idea if many people still use a Colortune.

[jalexquijano]

On 11/4/2021 at 9:33 PM, psdenno said:

The Colortune will give you a good visual check on what's happening during combustion.  When I used to adjust the carbs, I would follow the steps in the shop manual and then check with the Colortune for any final adjustment.  No idea if many people still use a Colortune.

Tuned both carbs at 1000 rpm, balanced them and adjusted fuel mixture knob at 3.5 turns clockwise. Ill take a drive to see if i need to open them more. 

[siteunseen]

It's counter clockwise.

You turn them clockwise to raise them, less fuel. Counter clockwise to lower the needle, more fuel.

The insructions say turn them clockwise towards the passenger's side until snug then counter clockwise towards the driver's side to 3 full turns for the base setting. If the plugs are white go down to 3.5 turns counter clockwise and so on, do half turns for the fine tuning.

Think of laying under the car when turning the knobs. Right would be towards the passenger's side raising the needle which fills up the tube with more needle there by lessening the fuel.

Hope that makes sense.

[siteunseen]

Just read Marks comments, sorry if I've confused the conversation but I always think about the needle going up or down into the jet that determines the amount of fuel/air.

The jet screws in and doesn't move. The needle is adjusted with the knobs.

Right Mark? Should I try getting my foot in my mouth?  I'm not sure I can do that move anymore.

 

Edited November 6, 2021 by siteunseen

[siteunseen]

Foot in mouth, figuratively.

The knob adjust the nozzle into the needle so I am wrong.

SORRY!

 

[jalexquijano]

Ok after taking the car for a ride and adjusting the fuel mixture to 3.65 turns front and rear carb at 1000 rpm, the car ran pretty well but presented the following issues:

1. Backfire at exhaust when releasing gas pedal at 2nd and 3rd gear. Pops, pops....

2. Car started stumbling after staying parked on idle for 10 minutes. Could be due to some problems with vapor lock we had discussed in the past and never solved.

I guess ill have to live with this problems and only use the car on weekends to avoid traffic jams during weekdays.

Spark plug 1 2 3 4 5 6

Edited November 10, 2021 by jalexquijano