I just don't get it. Having several problems with this thing.

First, I have a modified HEI Vacuum advance distributor. Had the thing working right for awhile...it advanced slightly at idle making idle adjustments difficult, but using any spring heavier than the lightest two wouldn't bring in the 20+ degrees of mechanical advance I needed. I took it apart again to discover that the weights were so loose that they could 'overlap' the centerweight, prohibiting mechanical advance. The shafts and bushings were fine however. If anything, the weights themselves were wallowed out. Anybody have any problems with this? Also, the instructions that came with my advance kit said there were colored springs in the kit...however, mine are silver and gold and black. Which are heavier?

Also can't get the carb tuned right. Cold starting is a bitch, but I have the choke set for about 1700 RPM's cold. I notice that after I drive the car, get it good and hot, shut it off, and come back 5 minutes later, the choke comes back on. What the hell?

I also tried to set the idle. I had to set the idle to around 1250+ in park or neural in order for it not to stall when I put it in gear. There are no vacuum leaks on the motor and everything is new and it runs healthy otherwise...although over the last few days it's been running more like my stock 305 than a modified 350. If I set the idle any lower, the car will idle at around 550 in gear, and the idle will get slower and slower until the motor stalls. I also can't get any chop at idle out of the LT4 hotcam, if that makes a difference. Anybody have any ideas? I'm stumped...I'm about to ditch the Q-jet and get a holley. Any help would be great guys! Thanks!

 

Are you using stock weights and centerplate or an aftermarket kit? Never mix and match stock stuff with aftermarket stuff- it'll never work right.

Worn out advance weights are very very common with high mileage HEIs (the hole wears oval aroung the pin). Chuck the weights and get new ones. Or pull better ones from a junkyard HEI. The most bommon and best weights to use are stamped "106" on them. If your weights have a plastic insert that snaps into the weight hole and rides around the shaft (kinda like a plastic bearing) that should be relatively easy to find as well. Hint: Go to Pep Boys and buy the super-cheap Spectre HEI advance weight kit and steal the plastic inserts out of it AND THROW THE REST OF THE KIT IN THE TRASH.

Also, the advance mechanism on the top of the distributor shaft usually gets "gummed up" as well making advance slow and sluggish. Try manually turning the rotor like it's advancing and then let go of it. It should SNAP back against the force of the advance springs. If not, it's gummed up and will require some cleaning out to get it back to tip-top shape. Email me if you have this problem and I'll help you out with the how-to on this.

A sluggish, sticky or otehrwise limited mechanical advance mechanism can CERTAINLY make a stout 350 feel like a weak smogger 305. It can make a HUGE difference when you get it right.

Don't try to tune the idle until you get the distributor right or you'll be chasing your tail forever.