The V8 Owners Forum -

hi there i have a 3.9 36D engine runing stage 3 heads, tubualr manifolds, 500 edelbrock and intake.
recently rebuilt and all pistons are producing 165+ on a pressure test.
the car has a edelbrock fuel pump running 5.5psi at the carb. the carbs been rebuilt.
and the issue is when the car is drag racing it pulls off very well and then suddenly out the blue nuthin like its ran outer fuel let your foot of the accelerator then put it down again its back but this happens every run witho ut fail and is slowly gettin worse. does any one no any ideas the carb is set up and floats set perfectly aswell this has been done.
also all new fuel hose and a fuel pressue gauge with clock. it has electronic dizzy and been set up according and vacuum removed. brand new iridium plugs. dizzy cap.

any suggestions wud be great.

Are you running a high pressure pump which feeds high pressure fuel all the way up to the carb where it is then regulated down to 5.5 PSI?

If not and your car has enough grip you could be ending up with no fuel going into the carb as you launch off the line due to the 'G' that you are pulling.

I think that the Eddy carb might suffer this worse then some other carbs because volume of fuel in the bowls is quite small.

Just my humble!

the car of the deck is great and goes like a rocket til about a 1/4 way up track then it happens, it never happens off the deck some times it gets nearly all the way up then does it. everything possbile has been changed. only two things left to change are the dizzy and the swap the eddy to a holley

Hi
most probably the fuel level in the bowls being effected by the acceleration, all 4 barrels suffer from this and there are various ways of reducing it's effect, there will be a kit for the eddy for this, normally consists of some form of baffel for the float bowl and some replumbing of the fuel feed into the carb, some carbs, as part of the solution have a second float bowl kit the David Vizard book on carbs has detailed information on this and how to sort it.
http://www.amazon.co.uk/How-Build-Horsepower-Carburetors-Manifolds/dp/1884089143/ref=sr_1_15?ie=UTF8&qid=1314119151&sr=8-15
best regards
Mike