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-   -   good news___bad news ( flexplate & quadrajet ) (http://www.hotrodders.com/forum/good-news___bad-news-flexplate-quadrajet-223871.html)

LEROYDOZOIS 09-10-2012 06:34 PM

good news___bad news ( flexplate & quadrajet )
 
(GOOD NEWS)so i got the truck back last night, and turns out my flexplate was cracked in 3 spots, which explains the horrible grinding noise when it would hit the starter. our buddy replaced it and now i just need to reshim the starter a little to make things perfect.



(BAD NEWS) i took advantage of the cooler monsoon weather last night and swapped carbs on the truck, i put the quadrajet back on and hooked everything up like i always do. started it up and it ran like a sick cat( nothing changed since last time )

so i waited till this morning( light ) and started it again, same thing, adjusted the mixture needles like to where they were long ago ( 6.5 turns out ) and it still didnt do much.

went to work and when i came home, i dug the timing light out and fired it up once again. 12* base timing, hooked up the vac adv and it revved up ( yaay ) so i was able to lower the idle speed quite a bit...

got it to idle down to 800 rpm and its still off the charts lean... looked at the idle screw and its1/8th inch from the tab on the throttle shaft... tried to rotate the shaft closed and the butterflies are closed... so ive finally gotten stumped, i have no idea what to do. my next move might be taking it to a guy here in my town that my buddy referred me to, hes an older gent and apparently hes super nice and helpful.



thankyou all for the help guys, i cant thankyou all enough =]

oldbogie 09-10-2012 06:44 PM

Quote:

Originally Posted by LEROYDOZOIS (Post 1589664)
(GOOD NEWS)so i got the truck back last night, and turns out my flexplate was cracked in 3 spots, which explains the horrible grinding noise when it would hit the starter. our buddy replaced it and now i just need to reshim the starter a little to make things perfect.



(BAD NEWS) i took advantage of the cooler monsoon weather last night and swapped carbs on the truck, i put the quadrajet back on and hooked everything up like i always do. started it up and it ran like a sick cat( nothing changed since last time )

so i waited till this morning( light ) and started it again, same thing, adjusted the mixture needles like to where they were long ago ( 6.5 turns out ) and it still didnt do much.

went to work and when i came home, i dug the timing light out and fired it up once again. 12* base timing, hooked up the vac adv and it revved up ( yaay ) so i was able to lower the idle speed quite a bit...

got it to idle down to 800 rpm and its still off the charts lean... looked at the idle screw and its1/8th inch from the tab on the throttle shaft... tried to rotate the shaft closed and the butterflies are closed... so ive finally gotten stumped, i have no idea what to do. my next move might be taking it to a guy here in my town that my buddy referred me to, hes an older gent and apparently hes super nice and helpful.



thankyou all for the help guys, i cant thankyou all enough =]

Old Q-Jets often wear out the throttle shaft bore in the housing and pull enough air to idle on right around the shaft(s). The solution is to put brass bushings in there to restore the proper shaft to bearing surface clearance.

Bogie

LEROYDOZOIS 09-10-2012 07:27 PM

Quote:

Originally Posted by oldbogie (Post 1589668)
Old Q-Jets often wear out the throttle shaft bore in the housing and pull enough air to idle on right around the shaft(s). The solution is to put brass bushings in there to restore the proper shaft to bearing surface clearance.

Bogie

i just installed bushings on both right/left side of the truck, i thought the whole problem with the carb was that, and i was dead wrong :smash:

spinn 09-10-2012 09:48 PM

How are you determining the lean condition, lets hope not plugs. My qjet is one of the best carbs ever used. The idle screw is not touching the tab but the carb stays at 800rpm. Was a drill taken to the idle bleeds or idle ports, that would keep it running high. Is the choke operational. If not you could remove the choke linkage rod to check if it would baseline hot. 6-7 turns out is not the baseline.

LEROYDOZOIS 09-10-2012 10:20 PM

Quote:

Originally Posted by spinn (Post 1589706)
How are you determining the lean condition, lets hope not plugs. My qjet is one of the best carbs ever used. The idle screw is not touching the tab but the carb stays at 800rpm. Was a drill taken to the idle bleeds or idle ports, that would keep it running high. Is the choke operational. If not you could remove the choke linkage rod to check if it would baseline hot. 6-7 turns out is not the baseline.


my determination of the lean afr is with my afr meter.
my idle bleeds havent been touched. i drilled out my new idle tubes to .042 like how my old ones were.

--------------------------------------------------------------


and as an update to my original post.

i took the carb off to put the 1406 back on so its not a dead vehicle, and noticed the throttle body plate was dangerously loose, and i assume with new gaskets i didnt tighten them enough to make up for the give of the gaskets.

ill put it back on tomorrow morning and see if that was my problem. i swear i heard the noise as if a vacuum hose were disconnected. i assumed it was the air flowing through the primaries. :rolleyes:

spinn 09-10-2012 10:32 PM

Drill idle tubes to .042" would be good with a cam 214-225 duration at .050 and you need to balance it with some other things.

What is your build?

LEROYDOZOIS 09-11-2012 09:56 PM

sooo.
 
im not sure if i want to keep bothering with the quadrajet, i drove all over the place today and im getting 10 mpg stop/go intown 35 mpg speedlimit... not sure if i should screw with something that majority of people said id never be able to achieve.


and no luck with the qjet, put it back on and it still wont idle so i think im done playing with it. i might sell it on ebay as a whole kit, cliffs book and all.

oldbogie 09-12-2012 10:50 AM

Quote:

Originally Posted by LEROYDOZOIS (Post 1589987)
im not sure if i want to keep bothering with the quadrajet, i drove all over the place today and im getting 10 mpg stop/go intown 35 mpg speedlimit... not sure if i should screw with something that majority of people said id never be able to achieve.


and no luck with the qjet, put it back on and it still wont idle so i think im done playing with it. i might sell it on ebay as a whole kit, cliffs book and all.

Could be, a friend of mine just went through that trip with the Q-Jet on an original 350 in his 1970 pickup. I put some time into it as well, finally recommending replacement after several unsuccessful tries at bringing it in. I suggested replacing it with the Holley 4175, but at 400 dollars he was pretty resistant to spending that much money. But after spending nearly that much on fixing the original Q-Jet to no satisfactory result; then purchasing a rebuilt Q-Jet from a national rebuilder and seller of those things that upon firing the engine up blew the fuel inlet fitting out of the carb body, soaking the engine compartment with gasoline that fortunately didn't catch fire. When he called me to come over and take a look I found the inlet threads in the body were mostly gone and that someone at the rebuilder tried to connect the body and fitting with epoxy. After that Scott relented and bought the Holley from a well known hot rod catalog. They delivered it the next day. He put it on only asking me how to wire the electric choke.

Out of the box it brought the 350 back to life so well it didnít need further adjusting than to set the idle and the transmission modulator link. He was concerned about jet sizes, like it seems everybody that has a Holley worries about. I got over to his barn a couple days later to listen to it. It ran so well I recommended leaving it alone, as messing with it was more likely to screw it up than improve what it was already doing.

Now he's got to replace the wheel bearings on his boat trailer. Like backing into salt water to launch and never cleaning and repacking the bearings was something he could get away with forever.

Bogie

LEROYDOZOIS 09-12-2012 11:10 AM

i know quadrajets are great carbs when set and 2 other toys i have has them, but my buddy showed me what he did to his 1406 they he found completely locked up on a car that rolled over and caught fire, he showed me his complete cleaning and rebuilding process and then he showed me videos of it in his rock crawler and i was dumfounded. he then offered to do the same to mine but i had already done 50% of the mods he did and the rest i can do for a few hrs work and a couple bucks.

besides the idle circuit clogging on me 2 times because of a bad fuel filter and a piece of rubber getting stuck in the float needle ( also the filters fault ) the carb has been great to me.

i have a steep driveway and ive parked in the middle of it and reved the truck to 2000 for over a minute without things going south, both upways and downways with no issues .

LEROYDOZOIS 09-13-2012 09:48 PM

so
 
i took the quad to the carb shop that i was getting a few gaskets from today and told him about my problem. he showed me a plug in the base plate that controls the power piston ( same as APT screw but reversed/different ) and when i unplugged it the screw was totally seized, so instead i bent the rod up and it made a big difference but its still very lean. now it jumps from 17.2 to off the chart so it made a huge difference but still not enough...

i got another carb on it right now so im not worried atm. maybe one day ill get it fixed


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