Distributor Question
- Thread starter Boaf 32
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- Thread starter
- #22
Well I noted in the distributor that the Centrifugal was a bit stiff. Cleaned, lubed weights and it was smooth. So I know they are spinning open. Dropped it in, set the timing with the vacuum line off and BB spot on. Put the vacuum hose on and the vacuum smoothed the idle, as it should.
Took it for a test ride and still had some "rev limiter" issues when accelerating. Going up a hill in 3rd gear, pop out the carb. ARGHHHHH.
On to the next item to check. dialed the Weber 32 / 36 carb down to 0. Turned out 2 turns and will go for another ride. Starting the cold motor still sux. @Coolerman @Dizzy @Pin_Head . Calling out the boys. What else to try? The cold weather is crapola!
Boaf
Took it for a test ride and still had some "rev limiter" issues when accelerating. Going up a hill in 3rd gear, pop out the carb. ARGHHHHH.
On to the next item to check. dialed the Weber 32 / 36 carb down to 0. Turned out 2 turns and will go for another ride. Starting the cold motor still sux. @Coolerman @Dizzy @Pin_Head . Calling out the boys. What else to try? The cold weather is crapola!
Boaf
Your fuel pump might not be keeping up with the needs of the carb. It'll show up most on acceleration and under load. Backfire out the carb is consistent w/ that kind of lean condition.
I'm late here--sorry if you already checked that.
I'm late here--sorry if you already checked that.
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- #24
You may be right. I am investigating this lean condition because most of this happened when I went to a 32 / 36 Weber from a 38 / 38 (which was way too rich.
I am working on the fuel mixture tomorrow. I always thought that Backfire was ignition, carb burp was timing. I'll do some lean research. Thanks.
Boaf
The 32/36 is generally regarded as being not enough carb for them.
- Thread starter
- #28
So the Carburetor that is on now, Weber 32 / 36 is too little fuel (crap). The 38 / 38 I replaced was to much fuel, due to possibly improper jetting. It would spew black smoke even when I leaned out the carb to near .25 turn on the mixture. What is the perfect carb? the Aisan 2F stock? Thanks Pin_Head.
Boaf
The screw is only for adjusting the idle fuel mixture. It has no effect when the throttle is opened. To change the running mixture you need to change the main jets.
I'm not a carb hater. There are a lot of different carbs out there and most of them work just fine. The Stock Aisan is a good carb, but it is a little more complicated than a Rochester or Holley.
I'm not a carb hater. There are a lot of different carbs out there and most of them work just fine. The Stock Aisan is a good carb, but it is a little more complicated than a Rochester or Holley.
The video from Pierce Manifolds disagrees. If you excessively close the idle mix screw(s), the 38/38s two screws--it is a synchronous 2-barrel, then you influence back pressure on the Weber's main circuit, causing them to run rich, hence, they are only semi-independent circuits. This applies to the 32/36 progressive carbs as well.
12:00
- Thread starter
- #34
What jets for Main and Idle jets would you run on a Weber 38 / 38? The only problem I had with the 38 / 38 was 8 MPG and black smoke at idle. OR What jets for Main and Idle Jets would you run on a Weber 32 / 36?
I find I have two to choose from. Thoughts gents?
Boaf
I find I have two to choose from. Thoughts gents?
Boaf
@Pin_Head : Additional documentation:
iirc i had the smallest idle jets i could find for a 38 38
O2 sensor and gauge, so you don't risk the slight possibility of wasting gas or roasting exhaust valves.
Or, here is a thread that might help:
Weber 38 DGAS : info + settings + tuning
(Edit) more elevation specific:
***Weber Carb*** Adjustment Thread
Or, here is a thread that might help:
Weber 38 DGAS : info + settings + tuning
(Edit) more elevation specific:
***Weber Carb*** Adjustment Thread
Last edited:
- Thread starter
- #39
That's what I am looking for. I still have my old 38 / 38 and going to replace the idle jets to start. The smoke is black at idle, and the fuel mileage from the main jets is around 7 - 9 MPG.
But, there is no bucking, hesitation.
This will be a new job for me, never jetted a carb before. Need to balance performance and mileage. I do not even know what jets are in there.
Boaf
Folks on the Nissan forum run the 38/38 on the tiny 2.4L 4 cylinder (nearly half of the displacement as a 2F) with as good of fuel economy as I get with my 32/36 (which is actually undersized without tweaking for my 720 minitruck here at 6,800' to 10,000' above sea level). A big carb can run less throttle and smaller jets, but a small carb will be challenged at idle and wide open throttle for getting a proper mix of air.
The range of sizes of jets listed from Pierce Manifolds should be adequate. Do yourself a favor and see if you have the same overall shape, not size, of the primary and secondary idle jets on the 38 synchronous. On the 32/36, one is different from the other, and it only is specific to the manual choke DGV, not the DGEV, iirc.
The range of sizes of jets listed from Pierce Manifolds should be adequate. Do yourself a favor and see if you have the same overall shape, not size, of the primary and secondary idle jets on the 38 synchronous. On the 32/36, one is different from the other, and it only is specific to the manual choke DGV, not the DGEV, iirc.