Topic: Quadrajet Rebuild

[4SPEED]

time for a rebuild.  its been not working right , just slowly getting worse.  I took it apart to see if I could see anything. there was some grit in the bowl .  but when looking at all the gaskets and the pump assembly and other parts , they looked worn.

and after talking to Cliff  (Cliffs High Performance)  http://www.cliffshighperformance.com/
the worn parts are due to the ethanol in the gas and cheaply made overseas parts.
   
Pluss with the Performance of my 400 I will do a few other mods to the carb.
so I ordered his HP Rebuild Kit w/Idle Tubes  +  Secondary Metering Rods  + Bottom Plug Kit + Secondary Cam and Spring

I'll show ya how to rebuild it , but wont get into much detail on the how to's unless you ask.  there is really nothing to them and I cant see paying 200 to 300.00 + the kit ,  to have it rebuilt.  Cliff's rebuild can cost up to 600.00.

the cost of mine should be 175.00 when done. 
130.00 kit w/mod parts,  the top plate and body with a new CAD finish 45.00






 

[4SPEED]

pics of the tare down.  take lots of pics so you dont foget how it goes back.

[4SPEED]

the parts are ready to go to Cliff to get a new CAD surface.  should look like new.




the kit showed up today too. 

[Joeyinal]

very good post.will be very helpful when i start to rebuild mine.


my gallery
http://www.78ta.com/gallery2/main.php/v/JoeyinAL/

[4SPEED]

it will be a few weeks , cliff will have the parts for a good week.

[Serpiko]

cool! Very interesting topic, I still have to figure out if with my little knowledge I can rebuild my QJet.
Stupid question: How do you figure out if the QJet needs to be rebuilt?
Thanks for posting

[ta78w72]

cool! Very interesting topic, I still have to figure out if with my little knowledge I can rebuild my QJet.
Stupid question: How do you figure out if the QJet needs to be rebuilt?
Thanks for posting

The performance of the car will tell you.  You'll get hesitation and otherwise poor performance.  Eunan and I rebuilt one of his spare carbs this week.  We didn't do a complete job but we did replace some of the parts and cleaned everything.  It was a mess.  I doubt a car would run with that carb on it.  After the rebuild, Eunan installed it on one of his T/A's and it performed great.  We spent about ten hours on the rebuild.  Most of the time was spent cleaning it.

[ta78w72]

4speed, did you send him the butterflys for plating?  He does that on the carbs he rebuilds.

[4SPEED]

no I forgot to add them to the bag of small parts. dam....

this one worked really good at first,  then went to hard to start ( carb losing it prime over night) with a unburnt gas smell. then to falling on its face when I hit the gas.  to just wont run right.

I think all it needed was a new pump, stiffer spring and air tubes.  oh and new bottom plugs to keep the gas in the carb.

[ta78w72]

That's not bad after all these years.  My 78 delivered new with a hesitation.  The dealer was never able to fix it so I replaced the carb with a bolt on Holley which worked great for about 20 years.  Then I had the original carb rebuilt and that worked great until my daughter wrecked the car. 

Was the float needle valve connected on the rear of the float, or between the bracket and the float?

The one Eunan and I rebuilt had the needle valve spring on the end of the float, between the bracket and the front wall of the carb.  I noted that and commented that I thought that looked incorrect, so I checked the manual and saw it was on the wrong edge of that float bracket.

[4SPEED]

[Grand73Am]

You may already know this but....according to the Doug Roe Rochester carb book, and a q-jet rebuild video I have, and from the q-jets I've taken apart, the needle should hang in the middle on that rounded side that faces the float, not through a hole.

[ta78w72]

Correct, the service manual specifically states not to set the float clip in the hole.  Good luck getting it to stay in the middle though.  It wants to hang a little to one side and that's where the manual shows its position on the float arm.

I had that clip come off the float arm.  It took me a long time to figure out why the car wouldn't start.  I've never seen that happen before.

[rad400]

Cool Doug thanks for posting.

[4SPEED]

I talked to Cliffs on Friday,  I should have all my parts back by Wensday