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L20b with dual weber now running...kind of


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Hey all,


I now have the dual webers installed, linked and synched!


The car runs great at idle and revs smoothly at idle. When under load, all sorts of misfiring happens, especially under acceleration.


I have no idea where to start, a friend recommended checking the fuel pressure. Other sites say my jets may be to rich (running f8 60 idle jets). Other ratsun posts say it may be the dizzy (stock with the pertronix, let me know what I should be running and where to buy). Lastly the carbs may be junk. I did adjust the valves.


Sorry for the rambling. I'm just stuck and really want to hit the road in good shape.


Thank you!



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Does it run at 2000 rpms steady? Or just under load?


Also, I'm sure there is a recommended jet setup for an l16 or l20. Would find that and reference it before assuming there are issues with other components.

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Idle and hand revving isn't enough load. Accelerating in gear demands more gas. I would say it's too lean. How you would fix this on side drafts I have no idea.



See what jets others used on a 2 liter engine as a base starting point.

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Idle jet may be a tad rich. What main jet, emulsion tube and air corrector are you using?


Stockish l20b? 40 or 45's or 48's?


Too rich will make it gurgle and fart and miss.. Too lean will sorta do that too.


How far out is your air mix screws? We also need to know the model number because dcoe 9's have a different thread pitch on the mixture screws than a 152

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Hi all,


Sorry for the delay.


The misfiring happens only under load.


With regard to it running lean, I haven't changed the fuel pump so it may be providing just enough when sitting but not enough under load demands. In going to borrow the AutoZone fuel pressure tester.


The spark plugs are brand new and I only took her around the block a few times so reading them would be to premature.


I'm picking up a timing light tomorrow or Thursday. Ill set it at 14. The carbs are very old 45 dcoe but have been cleaned thoroughly and hopefully aren't too far gone.


Ill have to check my mains, but the idle jets are f8 60.


I hope I addressed everyone's posts. My next steps are going to be:

1 pray

2 check the timing

3 check the fuel pressure

4 inspect the carbs

5 resynch the carbs (sans the linkage)

6 reconnect the linkage

7 repeat step 1

8 test drive



Please let me know if I missed anything.


Thanks again,



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my concern is that the car sat for twenty five years and the diaphragm maybe worn. It is probably the original pump and like the rest of the car, it may need freshening. I do appreciate the input and every comment has me examining different systems a bit more in depth.


The fine folks at Weber do no want more than 3psi. Had there been a need to use a fuel pressure regulator?

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