Need help, engine wont start + backfire/squeeking noise

[Wolverine]

I'm sorry if this has been addressed before somewhere but i looked and couldnt find anything really. First off I've got a 66 4x4 with a newer 355, Dart heads, lunati .268 flat tappet cam, forged rods and pistons, scat crank and a carter competition carb. Anyway, I had this engine built in '07 and broke it in on a dyno and then ran it a little bit in my camaro. It sat for a few years and i just dropped it in the truck. It started right up but idled really fast. I saw that the primary throttle blades were sticking so i pulled the carb and cleaned it and got the blades to close. Then at the same time, I dropped a new distributor in and wired it to the MSD 6a box i had in there. After that the engine would turn over, but not start or run for only a second then die if i touched the throttle. I played with the idle adjustments and pulled the dizzy out and fixed the timing a little and put it back in with TDC lined up, etc. Today, the truck is making a squeeking noise form who knows where and make a huge backfire when i tried to start it. Any advice would really help and I'm almost about to give up.

[72chevyk10]

a backfire out the carb? or exhaust? out the carb is usually a timing issue, out the exhaust usually is to much fuel. the carter/edelbrocks dont like much psi goin through them. 5.5 is pretty much the max for fuel pressure. mine likes 5psi best. have you tried puting the old dist back in?

[vectorit]

What do the spark plugs look like?

Gap set according to specifications on your upgraded ignition components?

Seems elementary, but I recently had this happen to me.

I put in new plugs, and I forgot to open up the gap since I am running an upgraded ignition system. Engine would not stay running, and I pulled the plugs to gap them and they were soaked with fuel.
Put them back in after proper gap set, and it fired right up and idled fine.

Sometimes it's the simple stuff.

[ol'blu72]

Call me captain obvious but it has to be something with the carb or dist. I would go through both to make sure Murphy didn't get you when messing with them. Its normally something easy that got brain farted. Recheck the dist. install (is the rotor at #1 when #1 is at TDC compression?) recheck the timing. Then I wold pull the carb and go through it again and re install. Other than that look at whatever else you adjusted or removed. Where is the squeal coming from?

[Wolverine]

Thanks guys for the quick responses, I really appreciate it. Unfortunately the old distributors wires broke off so I can't put that back in. The spark plugs don't have alot of gas on em but since they're the old ones ill put a new set in and gap em anyway. What should I gap em at by the way for a modded engine and ignition?
The backfire came out of the exhaust and scared the crap out of me, and I can't determine where the squeeking is coming from exactly but i think its somewhere on the pass. side, it just started doing that today. Ill check timing again and make sure the carbs ok in the meantime.
Posted via Mobile Device

[csb#356]

Recheck the ignition wires to make sure they are in the right spot. I recently flipped the #8 and #6 wires and it ran but had a huge backfire out the exhaust, sounded like a gunshot. Sometimes when you're in a hurry stuff happens. Also timing too far retarded can cause that.

[truckdude239]

your starter might have gone bad