12 hours ago, Mark Maras said:

 BTW, I see no reason to check the fuel pressure based on the symptoms you've described.

Look the fuel pressure before i delivered the car to the mechanic was 4 to 4.3 psi. Nice pressure indeed. Just measured the pressure today and it is scarcely 3 to 3.2 psi. Could the metal filter become clogged when leaving the pump running for several minutes without the cranking the engine? If so does cleaning the metal fuel filter clear the path to 4.3 psi as when it was new? It really complicated to remove the filter with the pump fastened to the chassis.

Works well. 

https://zcardepot.com/carburetor-float-sync-tool-su-240z.html

3 psi-3.2 psi is not the problem. I'm 95% sure that your float levels are incorrect but it seems that you don't want to address this issue. Just because your mechanic has adjusted the floats doesn't mean they're right. And while I'm thinking about it, why are your mixture adjustments getting farther apart the more he works on it? You were about a 1/2 turn difference before, now there's 1 1/2 turn difference. Prove me wrong, Please. All it takes is a screwdriver to remove six screws, a beer and we can move on to fine tuning.

Maybe he's a little intimidated by removing the float chamber lids?  It is a little tough until you figure out how they need to be turned from horizontal to vertical to get the float to slip by, also RTVing the gaskets to the lids makes it much easier in the future.  

I would do what Black Gold Man suggested, go to that race track's pit area and find a Datsun mechanic.  Seems like he is using a Porsche guy?  I quit reading a year or so ago, my hair was falling out because I was "pulling my hair out" from frustration. 

I just want to deal first with the airtex fuel pump pressure and deal with the float level then. Just a quick question: does the metal filter at the electric pump gets dirty an avoids the pressure to rise if you leave the pump in the start position without cranking the engine ? This has happened 3 times to me. Always end up with a new pump.

53 minutes ago, siteunseen said:

Maybe he's a little intimidated by removing the float chamber lids?  It is a little tough until you figure out how they need to be turned from horizontal to vertical to get the float to slip by, also RTVing the gaskets to the lids makes it much easier in the future.  

 

 I'm not even asking for something that intimidating. I just want him to remove the suction chambers, pistons and see where the fuel levels are when the mixture screws (nozzles) are 2 1/2 turns down. The mixture screws can be returned to their original setting after the test. Both carbs could be done in under 5 minutes. Then it may be time to move on to resetting floats but not until we're sure they need it.

Ok. Let me set both nozzles at 2.5 and send you a picture of each.

 Jalex, while you have the pistons out take a close look at the needle bases to be sure the shoulder of the needle is flush with the piston base, NOT flush with the bottom of the recessed section. You should be able to see the fat base of the needle sticking out of the piston.

22 hours ago, siteunseen said:

Maybe he's a little intimidated by removing the float chamber lids?  It is a little tough until you figure out how they need to be turned from horizontal to vertical to get the float to slip by, also RTVing the gaskets to the lids makes it much easier in the future.  

I would do what Black Gold Man suggested, go to that race track's pit area and find a Datsun mechanic.  Seems like he is using a Porsche guy?  I quit reading a year or so ago, my hair was falling out because I was "pulling my hair out" from frustration. 

Okay took the front carb float out from another set of carbs i had lying around before getting into the car and messing it up. Two questions:

1. Can you point out from where to where must the gap of 9/16 or .55 mm be measured? What type of ruler shall i use?

2. Is it the same gap measurement on the rear carb?

 

Measuring with the lids inverted will only give you a starting point.  To fine tune, I find it best to use clear tubing on the bowl outlet nipple and holding up next to the float bowl exterior that has been marked 23mm down form the lid/bowl joint.  I know this has already been said, but I fooled around with multiple methods before using this simple approach only to find out all my previous attempts resulted in close but no cigar.

My car runs awesome but is a B**ch to start when cold...contemplating adding an electric pump: Airtex 8016S

3 hours ago, David F said:

Measuring with the lids inverted will only give you a starting point.  To fine tune, I find it best to use clear tubing on the bowl outlet nipple and holding up next to the float bowl exterior that has been marked 23mm down form the lid/bowl joint.  I know this has already been said, but I fooled around with multiple methods before using this simple approach only to find out all my previous attempts resulted in close but no cigar.

My car runs awesome but is a B**ch to start when cold...contemplating adding an electric pump: Airtex 8016S

.55 inches ?? I really want to be sure of the starting point.

Edited February 12, 20187 yr by jalexquijano

On 11/2/2018 at 11:24 AM, JLPurcell said:

Works well. 

https://zcardepot.com/carburetor-float-sync-tool-su-240z.html

How do you use it?