Hi Ford fans,

I have a boat with a Ford 351W, an Edelbrock Performer manifold and a marine Edelbrock 600 cfm carb - brand new, btw. The carb replaced a 750 cfm marine Edelbrock but my problem wasn't solved.

Thing is that the engine runs great above 1 500 rpms. I also has a quite steady idle, new filters and a ignition system without flares (I think).

But - evertime I go from idle to light engagement, say 1200 to 1400 rpms, its starts bogging and behaving "unstable". I have of course replaced allt the gaskets.

Now I'm starting to think that the crank ventilation has got something to do with this problem. I have this ventilated spacer plate (and a heatshield) with a tube to one of the valve covers, could something there make the system coming of balance? Only a flame arrestor on top so I guess thats not the problem either.

I would be grateful for any advice!


Orjan in Stockholm, Sweden

 

Electric fuel pump or mechanical?

 

Mechanical.

 

Well I'm wondering if your low rpm fuel pressure isn't sufficient to feed the carb(?) .. just a guess

 

Hrrm, it was replaced 3 or 4 years ago, but it can definately be the problem despite that when I think about it. It might be that it delivers enough fuel for idling (not much needed) but needs higher revs to supply properly when more gas is needed.

The only thing that concerns me is that if it malfunctions on lover revs, why is it then capable of distributing the flow needed on 4 000 rpm's? I guess it's a diaphragm/membrane pump and if its damaged, would it then work better under load?


Orjan

 

Problem identified: took away the PVC spacer and put the carb directly on the manifold and voila, all the symptoms was gone. Suspect that the spacer is warped or anything, has grinded it and will try to put it back, othervice I'll have to replace it.

Thanks anyway,


Orjan