If something doesnt change im gonna sell it!!!!!

[orange72350]

Im at my wits end. If Things dont start going good, im gonna sell this old gal. It seems that the last 2 weeks has been nothing but bills and frustration. Front brakes, calipers, rotors and pads,power steering pump, all the hoses, blew both belts, flat tire, collector gaskets, choke problems. the whole 9 yards. anyhow, on 2 my query. Took the new engine out last night after timing/setting the carb. engine is very strong off the bottom, but when a guy kicks her in the a$$ to pass, she hestiates for about two- five seconds, backfires a couple times, then kicks down and boogies. That was until tonite. took her out on the highway from the farm 2 town. let her warm up, then really kicked her hard. ran hard all the way too town, about 70 mile an hour, then slowed down. pulled in to the gas station, killed it to get a pop, and come out. stomped on her hard 2 show off to the squeeze, and nothing. Put it right down, and there was nothing. she just hesitates and coughs. i took her on tha highway and stomped on her!! she just coughed, hesitated and bang. blew both header gasket like that. bang. gone. no more gaskets over a few exhaust ports. she is still gutless. nothing there. can someone please help me? if i dont get it figured out, im gonna sell the old gal. thanx in advance
dale

[orange72350]

ANYONE>>>>

[cnshoot]

tell me more about engine and cam carb set up

[orange72350]

rebuilt long block 350. rv cam, flat tops, performer intake, quadrajet, k+n, thats about it. i broke it in fine and took it easy for the first few days. it runs allight until now
thanx
dale

[SEVEND2]

hmm Points or HEI? Points could be floating on ya, Fuel pump running good, carb getting effient gas?

[cnshoot]

how did you set timing , rule of thumb for me has been to retard it tell its hard to start then ease up just a little and its not uncommon of quadrojunk to act like this i have found just a tape on the fuel bowl helps and if it does try a different carb like a carter

[cnshoot]

and also fix your exaust gaskets put good ones in there but make sure she dosen't back fire

[orange72350]

I set the timing at about 10 degrees btdc. it was running. hard. carb is getting fuel, fuel pump is brand new, everything else seems allright. tommorow is payday, so im gonna order a new carb. get a eldebrock 600 with vacumm secondaries
thanx guys. any other ideas?
dale

[SLS]

Have you tried backing the timing off to 8 degrees with the idle at about 550 in park?

Mine did about the same thing at 10 degrees. During hard acceleration mine stumbled, died, and was hard to fire back up, even after warmed up. I dunno, but it is worth a shot.

I set it up like I stated above, and now it goes like a raped ape.

BTW: I'm running a GM HEI w/ an Accel SuperCoil (no vacuum advance)...if that makes any difference.

[cnshoot]

thats why i dont set timing be light by ear i think mine runs best at about 6 dbtdc its a 425 hp sbc and i use a holley but they can be trouble for most but when they are right they run the best like i said try and tap on the fuel bowl with a hammer and see if that is it the quads just stick to easy and cheak the timming if you dont get alot of room out of it you could be 180 out it should run at idle from anywhere in about 16 degreeslike 4 before and 12 after just about it may not run good but it should if 180 out will only run in a 6 degrees gap

[cnshoot]

one other thing make sure all of the vacume hoses and real tight if not use zipp ties or hose claps are you still using the canister cheak it also

[Piston]

How old is this carburetor? 2 key things will cause what your having a problem with.. late timing and/or lean condition. Have you tried slowly easing into full throttle? How does it run then? I would suspect your going to find a lean condition causing it. 10 degree's is fine if your not hearing any pinging.
Check for any vacuum leaks then check and recheck your accelerator pump. If the pump is not working or is weak, anytime there is a sudden throttle opening it will fall flat on its face!

Oh, if your running points? I didnt see where you mentioned your ignition, but a point gap set incorrectly will cause this too. If its HEI, make sure you have a NEW 12ga wire run for the BATT terminal. Weak spark can directly affect performance.

[Randy70C-10]

Do quadrajets have power valves? I don't know anything about quadrajets, but it almost sounds like you have blown power valves. With Holleys, all it takes is one good backfire to blow them out.

[cnshoot]

no they do not have the natorios power valve that our holleys have but the best place for a quad is in the bed to be used as a paint stripper lol

[Yellow Cheyenne]

Just a thought. Check the mechanical advance weights in your distributor to make sure they are not sloppy loose or rusty to the point that they are sticky. It may be jumping the timing all over the place at the wrong time.

[72 2wd Blazer]

Originally posted by orange72350
rebuilt long block 350. rv cam, flat tops, performer intake, quadrajet, k+n, thats about it. i broke it in fine and took it easy for the first few days. it runs allight until now
thanx
dale

You mentioned below getting an edelbrock 600 cfm carb for your setup. Good call. It should make it run better. I too have a 350 rebuilt with something like an RV cam, 202 heads, etc. I installed the Edelbrock carb & performer intake (and still have the points setup until I go HEI) and mine runs great.

Let us know if the carb setup works for you.

[Wootdog]

I have the Edlebrock 600 with electric choke with HEI and it is awesome on my 68. Wootdog

[orange72350]

lets say i was to install the 600, with vacuum secondaries and electric choke. what would the install be like? hard? i work in a mechanical shop, so tools and help are no prob, but im new at this. how is the elecrtic choke wired? is it just a hot switch in the cab, or alittle more involved? how bout vaucuum ports? im hoping the swap is easy, cuase it really sounds like a good idea. btw, i have hei
thanx a ton
dale

[cnshoot]

the hardest part may be where your vacume is for the power brakes that is if you have those and everything else just goes back where the others were above or below the butterflies not your choke fly ( lol how do choke a fly) the only other thing that is hard is the fuel line you may have to cut and change things a little there also but none of it is to difficult just make sure that you can get parts so you are not stranded

[cnshoot]

the choke should be one wire

[pa_snowman]

let me give you 2 different things to look at that most people tend to not think about:

1- a Q-jet is a decent carb if you can get it tuned right...so..
check your throttle rod, are the bushings worn excessively? if they are either have a busing kit put in or replace the carb ( i have 2 edelbrock 600's and they are great, and low maintenance)
the other thing Q's are know for is sucking air or leaking fuel under the bottom where the sealang is that covers the factory drill paths. check it and reseal if neccessary.

2- have you checked the distrubitor mechanical advance to see if it if free. they tend to gum up with cooked oil over the years. most people check the weights but forget to check the actual shaft. i had one stick partually advanced and the truck would run good only at a certain speed. it took me awhile to find that also.

good luck

[RAT-AT-TACH]

im a newbie when it comes to these trucks and all but im thinking along the lines of spark plugs,are they gapped right,any ash build up,are the wires all good(no cracks) is your firing order right?

just my thoughts.

[mtdave2]

had a truck like that to. thing fought ever thing i tried to do. i called it the fyb... freaking yellow *****. ended up selling that dam thing.. good riddens