sd1 air filter

Ive got a 3.5 sd1 in my 90. I have changed the air filter box (sd1) to two lg cone filters,now it runs ****e.It doesnt want to open up and starves its self. I have changed the needles in the su's to richer ones but that hasn't sorted it either. I would like to add that v8's are new to me and although i did the engine conversion myself,i dont know much about the setting up etc. The engine was running ok before but it lacks oopth .A friend who knows a bit about v8's said get rid of that air box for a start,and here i am with less oopth than before. Can you give me a bit of info please. Adam.

Run it with no filters on and see what happens!

If you are running without the airbox you may need bigger jets in it which mean more fuel. Richer needles wont do.
Fit the air cleaner back on and get the carbs set up properly by someone who knows what they are doing.

ruffday said:

If you are running without the airbox you may need bigger jets in it which mean more fuel. Richer needles wont do.
Fit the air cleaner back on and get the carbs set up properly by someone who knows what they are doing.

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If they are SUs then you cant change the jets as they are all the same for each carb size you have to change needles.
Make sure the needles are seated properly and that the crank breather pipes on the carbs are blocked off or it will run very weak.
Those filters will not make that much difference to the fueling so it would have done to just richen it up a bit, unless the old filters were very blocked up.

Sorry I thought you could get bigger jets.

Not sure if the fuel pump is givin it enough now. Or the positioning of it isn't right. Couldn't find much on the net on the positioning of a facet style pump.