A Couple Carb Questions

[landpro00]

HEY EVERYONE!!!

I have a couple 750 Edelbrock Questions. Just so ya know, it's sitting on a Edelbrock Performer Intake mounted to a 454 engine and controlled by a 400 tranny. It has a Summit HEI distributer on it from what I can tell by comparing mine with pics. ALSO, IN CASE IT MATTERS, the Edelbrock replaced a factory TBI setup.

First question is: A couple times hear lately the truck hasn't started. The first time it was the day after all the rain from hurricane francis came through. The second time was last night. I'm wondering if maybe it's a humidty or choke related problem. The first time it happened, I tried it again a day or two later and it cranked right up and ran fine until last night. I haven't drivin it at night since the first incidence though and based on when it seems to be happening I'm thinking maybe it's a choke problem OR maybe it's because the temperature has been about 20 degrees cooler here lately than it was when the carb. was installed. Is it possible that it may just need to be adjusted to allow for the temperature change? ANY OTHER IDEAS?

Second question has to do with tuning the carb. and maybe fix the problem in the first question. I recently tried to tune the carb. the other day. I had to buy and use an engine analyzer to check the RPM's as the truck doesn't have a tachometer. Anyway, when the analyzer up, it doesn't show a steady RPM. It jumps around a couple hundred RPM's. Is that normal and if it isn't what would cause that? Right now, from what I can tell the idle is set at about 750RPM with the tranny in drive and the vacuum ports plugged on the carb. The distributer is at around 4 degrees BTDC. Is that to low, I've seen quite a few people on here say they have theirs set between 12 & 16 degrees?

Any input would be greatly appreciated!!!

USA IS #1!!! THANKS GO OUT TO ALL VETS. & ENLISTIES WHO SEE THIS!!! SUPPORT OUR TROOPS!!!

['85Silverado]

What is your timing at say around 3000 rpm? Setting the base timing depends on what the distributer adds and how much the engine 'likes'. For example, 4 degrees initial, 28 added from the dist, 32 total. On the carb, what exactly does it do when it doesn't start? With a carb, lets say it was running the day before, 1 pump and it should set the choke, crank it and it should fire right up. That is, assuming the choke is working correctly. If it doesn't start, pump it a few times and try to start it(if it's lean). If that doesn't work, hold it to the floor and start it(if it's flooded). My advise, first get the engine running perfect when it's warmed up(timing, idle mixture, idle speed), then adjust the choke to suit your needs. If you don't know how to adjust timing and the carb mixture/speed, find an old school mechanic. Shouldn't take them very long if they know what they are doing.

[landpro00]

Didn't get a chance yet to check the timing at 3000 RPM yet.

Both times when it hasn't cranked I've tried pumping the gas/ holding it to the floor and still no start. Cranks right up though the next day, VERY STRANGE to me.

Have been looking for six months now to find someone to properly tune the carb, but no luck so far. There's a Speedway down the street from my house and a couple teams have set up shops nearby, been thinking about stopping and asking them if they know of anyone I could take it too.

Maybe I'll try to swing by there tomorrow and see.

Let you know when I find out what the timing is at around 3000, maybe try to check that tomorrow to if I get a chance.

THANKS!!!

[MylilBowTie]

Coil module could be playing possum.