SUPERWAKE502

iTrader: (1)

Running stock lq4
gm intake
mighty demon 750 annular boosters
595-598lift cam at 112
6lbs of fuel pressure

Idles at 600 to 800 and the idle mixture screws are set. I have the msd 6010 box with the 4th chip. It has never backfired and seems to run perty good but it does have open shorty headers for now.

Problem: in all gears it has a stumble in the lower rpm but not really sure if it does it higher (forgot to try). Around 1500 it stumbles for just an instance and then it'll take off no problems. The plugs look awesome after 15 miles. Very clean, not white and not black, just a slight clean tan look. I did try the 3rd chip and it did it the same.

Hope you guys can help me a little. I plan on getting an afr wideband but not just yet.

Lee

forcd ind

iTrader: (7)

a couple things to try-you might have the pink pump cam now, try the green one, get agressive with it
you could also try about .005 smaller idle air bleeds-you prob have .070 now
you would prob have to pick up a set of hi speed a/b's, and drill them to .060 or .065, or maybe if you found some .010 wire(not likely), stick that in there
you could try a larger squirter first, but that might not do it
is it the single plane intake? they really need a shot of fuel

SUPERWAKE502

iTrader: (1)

Ok, I do have the pink pump cam and I was playing around with the timing pills and it seemed like the more timing there was the worse it got. So I backed way down to the number 2 pill and it was alot better but still falls on it face. I just ordered an AFR gauge so we'll see what that says when I get it.

Gm only makes 1 carb intake for these motors and I dont think it is a single plain.



Lee

Patrick G

iTrader: (14)

Sound like you need a lot larger squirter. Larger nozzle and maybe more aggressive pump cam. A cam with that much overlap will need a bunch of fuel to cover the hole when you whack the throttle open.

crainholio

iTrader: (2)

But...but...carbs are so much easier than fuel injection...

cowfarmer

if a quicker pump cam and larger squirters(also get the squirter hold down screw with the hole in the middle) won't get rid of it you may need to get the 50cc accelerator pump

SUPERWAKE502

iTrader: (1)

Thanks guys, I'll see what I can come up with.

Oscar Will

The GM intake is a pretty big volume single plane manifold, that's why you need a good shot of fuel off the bottom, you crack the throttle and the vacuum drops to nothing so you get a "lean stumble". You need a big shot of accelerator pump is all and as you already found out, pushing a bunch of timing advance doesn't help.

SUPERWAKE502

iTrader: (1)

Ok, I got the wideband on and it is leaning out to 16 or 18:1 when you stab the throttle. Once it catches up with itself its at 13 to 13.5:1 under load. There are 3 holes in the pink cam and I changed it to the one that comes on soon versus up the ramp. But it didn't help. I talked to a local tuner and he game me some more info and I want to share to see what you think.

1. I could try alot more aggressive cam to see if that helps but the guy told me the squirter would only flow so much, so I might need like a 50cc.

2. I could try a bigger primary jet to see if that helps. He said it will probably help my problem but then might be a little rich under load and therefore I would definitely need the 50cc squirter.

I think I'm gonna try a bigger jet with a different cam and see where that gets me. WATCHA THINK??????????????

Will holley cams and jets work with the barry grant 750

jay_lt4

iTrader: (4)

yes all the holley parts will work on the demon

forcd ind

iTrader: (7)

try the green cam in #1 position, you may also need to do the sec side also-then sneak up on the squiter a little-if that makes it better, then there is a bog out of the hole a little, then maybe look into a 50cc pump, cause the well is running dry
start with a green cam first-i had an 850 b/g bt and it needed it, then i switched to a quick fuel carb, same deal, needed a more agressive cam
try this little trick-while its idling, operate the carb by hand, then do it again while at the same time pushing down on the accel pump spring(giving it an earlier pump shot) see if you feel an improvment
make one change at a time, so you can go back if needed
if need be, smaller a/b's can be installed, but as a last effort

Shawn MacAnanny

iTrader: (12)

Yup 50cc accelerater pump, i also upped my timing to about 26 degrees at idle.

Shawn MacAnanny

iTrader: (12)

I bought this one and the seller is awesome with carbs. Has been very helpful with getting my carb set up correctly.

http://cgi.ebay.com/ebaymotors/ws/eB...m=260269274340