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Discussion Starter #1
I just swap my old 32/36 weber for a 38 synch weber, the 38 is way nicer than my old one but it seem to gurgle on take off, should I add a fuel pressure gauge, I have 2 different size fuel lines , because of the size I needed to use on the new 38, and the regular fuel line is small and needed to connect to the fuel pump, its goes from little to big on the fuel line. So should I just put a regulator to correct this.
 

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Let me respond to your questions with two of my own ...

a) What will a fuel pressure gauge do to eliminate the gurgle?
b) How will a fuel pressure regulator correct the difference in fuel line size?

A fuel pressure gauge will tell you what the fuel pressure is, and a fuel pressure regulator will regulate the pressure (or hold it at a constant setting) assuming that the fuel pump can deliver fuel at the pressure the regulator is set for, and in sufficient volume to meet the requirements of the engine - I don't see either one of them as correcting either of the problems you mention, if in fact they really are problems.
 

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Discussion Starter #3
I mean a fuel regulator not a gauge, I am not sure what the stock fuel pump on the sammys put out to begin with, but the engine is high compression 8,000 miles on it now , the pump was replaced when i did the motor. I know you can buy regulators that different in and out tips for the fuel lines, and with putting one on it would just make sure that the correct pressure is in the line at the carb.
 

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Are you referring to the mechanical fuel pump?
 

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To the best of my knowledge no regulator is required.
 

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Is the fuel pump a stock replacement? How does the engine idle and how does it run once you are driving along? If the fuel pressure is really high it could cause the issue you describe but if it isn't pressure a FPR isn't going to solve your issue. Can you get a hold of a fuel pressure gauge?
 

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Discussion Starter #8
It stumbles alittle when first started, when driving it is ok unless I try to gun from dead stop or open it up in forth gear, then it will hesitate a little, if I lay in to it slow it does alright but not what it capable of doing.
 

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Some more questions ...

1) What engine do you have in that Sammy?
2) What modifications have you done to the engine?
3) How was it running with the previous 32/36 weber?
4) What did the "new" weber come from and how was the jetting chosen?

A 32/36 weber is usually progressive and often jetted lean on the primary for economy and richer on the secondary for power, I suspect a synchronous 38 would be somewhat large for a 1.3, and I would expect opening both barrels simultaneously & suddenly to cause it to hesitate.
 

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Discussion Starter #10
1) What engine do you have in that Sammy? It has a 1.3

2) What modifications have you done to the engine? The engine has 10.2 high compression pistons with a mid to high range cam, and I did not bore the enigine at all. The rest of the car is stock small tires, factory crapy alternator, after market radio that powers 2 6 1/2 plk speaker were the old ones were in the kick panel.

3) How was it running with the previous 32/36 weber?The old carb never ran right because it was in need of a rebuild, but it ran all right, the 38 is running better than the old so far.

4) What did the "new" weber come from and how was the jetting chosen? I got this weber off ebay from a guy that bought it fron pearsons manifolds. They put 140 main jets, f50 emulsion tubes, 185 air correctors, 45 Idle, and 70 pumps, the weber was never used do to the fact that the sellers project fell through, but it was built for a 2.4 engine, and live over 5,000 feet above sea level, so it is harder for cars to breath here.

I just did a fuel pressure test and @ idle it was getting a solid 3 1/2 lbs the whole time even when giving it some gas, so I did buy a regulator to put on it, because i know the weber does not like to run on more than 3lbs
 

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Webber's require you to run a regulator set at no more than 2.5 -3 lbs. The stock Sammy pump is running at around 4 lbs. your assumption is correct . You need a regulator.
And you will probably want to re jet down.
At 5000 ft you will have to experiment though.
A synch built for a 2400 is going to be way fat for your 1300 .
... Boxcar ...
 
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