I just got the 406 back from the machine shop(changing valve springs) and all was running well for about 20 minutes. Then it starts stalling,stumbling like it's out of gas. I just put $20. in the tank.I had a similar issue when I broke in the cam. Ran gtreat for 20 minutes,then quit. I assumed it was the heat the first time,because it was sitting in the garage running 3000 rpms on a 90 degree day,but this morning it was cool and I was moving.I managed to get to the local diner and ate breakfast,but when I went to leave it wouldn't even start.Turns over fine,but no fire.I got my wife to pick me up and just for the heck of it I tried to start it once more. This time it fired right up,ran a second or two and stalled. I asked the wife to watch the fuel pressure guage on the carb while I cranked and the highest it got was 5 psi.For whatever reason the car finally started,and ran like a raped ape on the way home.(Even caught some rubber shifting into second by accident).When I got home I popped the hood,engine still running,and the fuel pressure was zero.How can this be?I had some other things to take care of and a few hours later again fired it right up,but this time I see 6 psi on the fuel pressure guage.Can a fuel pump cause this?And if so what are the preferred setups for supporting 500 plus horsepower. The current pump is an Edelbrock Street (110gph)pump,but I'm thinking of going electric,unless those that have done so already advise against it.

Oddly it wouldn't fire until after I plugged in the blower motor speed control resistor pack.The machine shop must have disconnected it.Once home I unplugged it while the car was runnning and it had no effect.

 

This morning I started the car and from the get go saw 7 psi on the fuel guage. After twenty minutes of steady 2000 rpm idle the pressure started to drop,eventually to zero,even though the engine was still running. I even blipped a few 7000 rpm pulls and it did not stall.What the heck's going on here?Vapor lock?Never had this problem before,what's the fix?

 

discard gauge

 

Fuel pressure gauges suck, I don't even look at mine anymore, lost the plug that goes into the fitting otherwise it would be in the garbage. It does the same thing yours does, most do, not sure if anyone makes one that actually works properly after tha motor warms up

 

If the car stalls and the guage indicated pressure loss,why discard the guage?If the car runs well for 20 minutes what else would cause it to cut out like this.Ignition module?

 

The non-liguid filled gauges can be used by averaging the needle bounce reading. But the liguid filled gauges are way out'a cal once the silicone heats up from eng comp heat. U could pull the rubber fill plug/leave open on gauge back and use as a dry gauge. The tiny little capilarary tube inside gauge is easily affected by any press from silicone fluid inside gauge.
This is why i installed a Holley electric fuel press guage ($70 Summit) as now i can read accurate fuel inside the cockpit - replaces the clock gauge hole. So far so good - 9psi to 9.5psi at NOT (200*F) coolant temp.

BTW MoneyPit i'm also recircing all the way from carb inlet through .040" orifice to the fuel return line (tank). U could look in my profile to find link to pix.

Good luck. cardo0

 

when it stalls i check spark. simple.

 

its probably a fuel pump. my stock mech. pump did the same thing. when i started it it was fine then died and fuel filter was empty, then ran fine with full filter, etc. i replaced the pump and now runs fine. you should get a clear fuel filter so you can see if it is pumping.