Car won't start with Demon - Third Generation F-Body Message Boards

Batass · 11-04-2009, 02:49 PM

The car ran great the last time I had it out, maybe a month before trying to start it. It would fire on ether, but wouldn't stay running. I swapped it out with a leaky edelbrock and the motor ran, so I'm sure its the carb.

I took it apart and sprayed cleaner through every orifice, then blew air through. I put the carb back on after the motor was warmed up from the edelbrock and it ran, but very poorly. At idle it would pop through the exhaust. So I took it back off and cleaned everything and still no good.

When I blew air, I saw mist come out the idle/transfer slot, so I know they aren't clogged, but when I took the secondary PV plug out, it had all kinds of jelly in it. I've just been running pump gas.

The only thing I didn't do was take off the baseplate.

The carb is a Mighty Demon blow through. I've been trying to start it without the supercharger piping attached.

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EvilCartman · 11-04-2009, 05:53 PM

What do you have your idle mix screws turned out to? What is the transfer slot gap set to? Have you messed with the idle air bleeds or idle restrictor size? If you have an Idle EZ setup, what do you have that set to? How are the float levels?

Batass · 11-05-2009, 02:00 AM

I've had this carb on for two years. Idle mix are 1 1/2 out, ez is 1 out. Don't know the transfer slot measurement, but they're square. Float levels are right in the middle of the window.

The car ran great, then sat for a month or so, then total screwage.

Badass355ciz28 · 11-06-2009, 11:48 PM

there are some little set screws in the metering blocks. sometimes these come out.......... thus why i will never run a demon carb ever again

EvilCartman · 11-07-2009, 07:16 PM

So you don't like being able to tune your carb easy eh? That's fine

The guy's who don't have those "set screws" that fall out usually end up tapping those holes and adding them to their carbs.

Batass, does it try to run at all? If everything is clean, I would think it should try and cough or sputter a little bit.

Batass · 11-08-2009, 02:40 PM

The only set screws that I know of are the ones in the pump circuit that I'm sure are only there to cover the holes from the hole drilling, since Holleys go diagonal right from the pump to the squirter, demons take a 90*.

It does sputter and fuel ignites in the exhaust sometimes. It ran poorly when I warmed the motor up with another carb and swapped while still warm.

I just took it apart again, and took the baseplate off. Found more shavings and the base gasket wasn't lined up perfectly. Nothing clogged though.

EvilCartman · 11-08-2009, 11:47 PM

I think the newer Mighty Demon's have just holes drilled instead of screw in emulsion bleeds. My Race Demon looks like the picture below and I think my old Speed Demon had the screw in type too.

I think you're just going to have to mess with the adjustments till it starts running. I usually put everything I can back to it's stock settings then go from there. One thing you could do right away is close off the Idle EZ then mess with that again once the engine is running halfway decent.

Batass · 11-09-2009, 12:51 AM

I pulled it apart again, blew through it again, and put everything back to stock. Something has to be lodged good, I don't think its dirt or something dissolveable, might be a shaving or maybe a piece of gasket. I guess I'm gonna tear it apart again and rig up something to force a lot of air through. Maybe some water so I can see any inconsistencies.