Well i've spent the day replacing a generator with an alternator on my 1776 with twin kadrons. New fuel pump new rod new alt stand and backing plates. Drove it round the block, Now she runs like a pig. It sounds like it missing or something and is blowing slight black smoke. The manifolds are also very cold (is that unusual). The only thing i disturbed were the plug leads on 1+2, the fuel hoses and a couple wires on the altenator. I NEED SOME HELP PLEASE.
Aaron:cry:cry
Rod length different to the one that came out
I have re-checked 1+2 again
It was 12volt generator before it came out
I will put a new fuel filter on today and check the timing.
I didn't disturb that much so i am at a loss to know what it is. Try again today! I disturbed one of the carbies slightly if it was sucking air would that have an affect.
Aaron
Black smoke generally indicates rich fuel mixture, ditto cold manifolds, so I doubt extra air in the mix would be the culprit. Maybe fuel pressure too high? Or perhaps the old fuel lines were clogged and the carbs were set/tuned to suit this, the new lines have maybe freed up the flow a bit.
Also possible plug or lead failure under load.
All serious "maybe's" of course, but worth checking.
A POSSE AD ESSE.
I live in my own little world, but it's okay, they know me here.
Spent the day trying to work out what i had done wrong. Took the new pump off and double checked the stroke. I was out by .1mm. So i put a another gasket to pack it up and got it just right at 4mm. I have also came down to the conclusion that it is slightly flooding for some reason. There seems to be plenty of pressure from the new pump. So it is off to the mechanics tommorrow as i need the car. I think it is flooding but still i am only guessing.
Aaron
Tested the pressure today and it was way to high and was flooding the carbs. Bought another new pump(different brand again) and it solved the problem. What is the difference between pumps???. Do i need to quote a fuel pressure when buying one???.
Aaron
Jaksc,
A lot depends on what your new fuel pump rod measured, the pumps pivot pin location and actuating arm manufacturing tolerances and how many gaskets you wind up using. A whole lot. Also there's where they are made can have an influence. For arguments sake a mexi Bocar might put out 3.5 psi max whereas a brazil brosol could do 4.5, and you need to cut down the rod or stack gaskets to lower the psi. I had to cut my rod to 100mm (was 101.1mm as supplied) and use 1 more gasket to stop my carb flooding. FYI I swapped a gennie pump and rod for an alternatior pump and rod.
Ctefeh
did you come up with the rod length and gaskets through trial and error or is there a formula to use to get the exact fuel pressure you want.
Aaron
Craig Torrens6 times Australian, 7 times State Hillclimb Class Champion
VW had two sizes for the rod length.:thumb
If you look at the arm within the pump (turn the pump upside down and look in it!) you will notice one sits lower than the other. The short rod length matches the pump which has the arm level with the base of the pump housing, the long rod for the pump where the arm sits about 5 to 10mm in.
Jaksc,
A generator rod is supposed to be 108mm, and an alternator rod is supposed to be 100mm. I knew I had an alt pump and so needed a 100mm rod to start. After fitting up and measuring stroke etc I figured on 1 gasket but wound up using 2. I have a lathe so rod trimming isn't a problem.
Measured it with a psi gauge after sorting needle & seat problems (I wound up using the original needle & seat as the new one wouldn't shut off properly).
For a glazed-eye read of pumps/rods/alt/gens try this....
Jaksc,
The Kads being pressure sensistive doesn't help much as it's another spanner in the works to deal with. Have you thought about a Holley adjustable low pressure regulator?
Bit spendy but it would be a definite fix and you can transfer it between cars or on-sell if you wish.
ctefeh wrote:Jaksc,
The Kads being pressure sensistive doesn't help much as it's another spanner in the works to deal with. Have you thought about a Holley adjustable low pressure regulator?
Bit spendy but it would be a definite fix and you can transfer it between cars or on-sell if you wish.
Regards
Ctefeh
Agreed, when I set up twin Mikunis on my old Dat16, the only thing that solved the pressure mismatch was a Holley regulator.
A POSSE AD ESSE.
I live in my own little world, but it's okay, they know me here.
Seem to have fixed the problem with another new fuel pump. Will look in to the pressure regulator also as a safeguard. Thanks heaps. There is more to this than i first thought.
Aaron
