ngus347

So I built a 347 stroker for my 1995 F150 and for the most part I am satisfied with my build. However there are still a few kinks I need some help working out.

Truck has a 347 with ProComp 225cfm heads, BBK SSI intake manifold, Comp Cam w/.480 lift, BBK 70mm TB, Venom 24lb injectors, and a Pro-M 75mm MAF. Truck has also been dyno tuned with a SCT chip.

Truck will hardly stay running when idling, will burble up and down, doesnt make a difference if its in neutral or drive. Wideband AFR gauge swings between 12 and 18.

Once driving, the AFR stays 13-14 and the truck runs great, just doesn't like idle or stop/go.

Is this due to the camshaft being too large for an automatic transmission? Or is this related to having larger injectors and the stock fuel pumps?

As of now I am leaning on the fact that the injectors dont have the duty cycle at idle or the pump doesnt supply enough volume at idle to make it idle smooth and not stress me out driving it.

Any help or input would be greatly appreciated!

sdmartin65

What comp cam did you use ?

ngus347

Comp part number is 35-512-8, grind number is XE2588GR-14

Let me know if you need more specs

sdmartin65

I just installed a rebuilt 302 with that exact cam, no drivability problems at all. I used stock rockers, roller lifters and pushrods. Preload was dead on spec with the stock setup. Do you have stock injectors and mass air? It's only a couple hour job to install them. If it wouldn't idle with that I'd suspect something out of sinc in the valve train. Maybe too much preload, something along that line.

ngus347

It's got 24lb injectors and stock fuel pump. I think not enough fuel flow may be my issue..

LOCO LAPTOP

I have a bigger cam. (35-349-8, XE264HR-14) and I don't have a problem like this. It could be the tune. I know mine wouldn't idle right until the tuner fixed it. I do have 24lb injectors (from a 2014 Mustang, Yes 2014) upgraded fuel pumps and adjustable fuel pressure regulator.