tool for adjusting quadrajets

[joebuick]

Hey everybody,,, Does anyboby know of a tool to use to adjust the air mixture screws on a quadrajet carb? I came onto a unmodified virgin carb out of an 80's chevy van. The van has 64,654 miles and carb had never been off the engine. Carb looks like new,!! The air adjustment screws had plugs covering them and after great difficulty,,,I finally removed them. The ends are obround with no slot for screwdriver. Is there a tool made that fits this obround end to be able to adjust the air mixture? What do others use? thanks

[85Bowtie]

Best tools I've used on a Q-Jet were a hammer and an available trash can.

[irishman999]

Originally Posted by 85Bowtie

Best tools I've used on a Q-Jet were a hammer and an available trash can.

C'mon man... c'mon.


Your talking about the d shaped heads that are hidden by the plugs you have to break out right? Im not sure where to find it but my dad has a special tool to turn them with a screw driver handle on it. You can also crush some small tubing to fit over it and turn it. I just rebuilt my quadrajet and did not touch the adjustments, it idles great.

[motornut]

yup spec tool has two dif ends for idle screws,a flexable spring/coil between to bend.
Around here an auto supply store would have them,
i could lend you mine,but your gas bill would suck

Irishman.......maybe it could get better

[joebuick]

I've seen it posted here that the way to tell when your carb is adjusted right is to fire the engine up and sit on the ground behind the tailpipes,,,,,,,,, If you don't pass out in a couple of minutes from the rich fumes,,,,,, you're OK and it's OK,,,,!!!
I went to the local Napa and Carquest and neither one had a tool. Guess I'll have to try the 1/4" tubing trick,, i bet that will work, it only has to work one time. But I'm prolly NOT gonna do the fume test,,,,,!!!!!
Hammer and trash can???? I don't think so. Man, this is a cherry carb and from what i know about carbs,,,, you get a good one, you better hang on to it. Just like anything else.

[ChevLoRay]

I have one that I believe I got from Snap-On, back in the mid-70's.

[Restrorob]

I picked one up off the tool truck years ago, A quick search turned up this one; http://cgi.ebay.com/ebaymotors/CARBU...motiveQ5fTools

[Malo83]

I picked up a kit for carbs at Auto Zone a few years back that comes with 5 different tips to adjust any carb that works great on Qjets

[CaliDude76]

This is what I use...

[1LowToy]

I bought my last one at Kragon Auto a few months back. I still have my Snapon socket but it's now located behind the left motor mount on my I6. I haven't lost it really.

[SS Delux]

CaliDUDE76 is that for setting both sides the same at once? did you buy it or make it ? my dad found ours at a garage sale in the packaging for like 50 cents a piece cause no one knew what they were.

[tucsonjwt]

Available at Autozone, and probably Pep Boys, Checker, etc. You can get a kit with several bits and a flexible shaft to drive it. It is called a "double D" bit. Mine works OK, but it is not very high quality - have to fiddle with it some to catch in the matching screw head.

[CaliDude76]

Originally Posted by SS Delux

CaliDUDE76 is that for setting both sides the same at once? did you buy it or make it ? my dad found ours at a garage sale in the packaging for like 50 cents a piece cause no one knew what they were.

My dad bought it years ago... from NAPA. It has different sizes on each end, I guess different carbs have different size air mixture screw heads.. But I just snake it to the screws and adjust away.

[joebuick]

Hey Guys,,, thanks for all the suggestions. I'm gonna go to Autozone ist thing in the morning. The local Napa or Carquest did not have anything maybe Oreilly's in the town up the road.

[joebuick]

YEP, I got one at Autozone this morning. one of the tips was a little loose and the next size was a little small so I ground the adjusting screw heads just a tiny bit and the smaller tip now fits great.. Thanks to all for your input.

[joebuick]

Hey Guys,,, well, I finally got around to plugging the vacuum leaks on my engine,,, had a good one on a round black plastic thingie that I think was for the A/C. Plugged that one and now the engine holds 15" of steady vacuum. I verified the timing to 8* BTDC, and tried to adjust the air mixture screws with my new gizmo from Autozone. I say tried, cause it did not make any difference in idle from all the way in to all the way out. I tried setting both of them to 2 full turns out and let it idle a little then adjusted all the way IN to closed, motor stumbled, so I went to almost all the way out before it made a difference in idle. another turn and the screw fell out, then the engine ran rough.
Actually, the engine now idles worse than before although it does seem to have a little more pep. Both screwa are at 3 turns "OUT" This engine has the timing tag behind the water pump and you have to be right on top of engine with the timing light. Not like others that have the tag on side.
What the hay have I done???
better yet,,,what do I do now ??

[Restrorob]

Get a can of carb & choke spray cleaner and shoot a little across the intake gaskets while at idle, See if it makes a difference in sound.

Did you remove and plug the vacuum advance hose before adjusting timing ?

Another check is plugging every vacuum port on the carb to assure nothing else is leaking.

If your sure you have no other vacuum leaks check the carb throttle shaft for any slop, If it's tight you could have a bad gasket (top or base section) causing a leak in which a rebuild would solve that issue.

[joebuick]

Hey Restrorob, I did not check the intake manifold gaskets cause the engine was holding such good vacuum at 15 " and was holding steady. First thing I did was to disconnect and plug the vacuum advance hose before setting the timing. One thing I had not mentioned, is that I suspected a vacuum leak in the power brake booster and so I went ahead and did an upgrade (like that word) and installed a booster and master cylinder from a 92 Suburban after a few mods.
One of the Guys here had a link to a site that spelled out how to adjust a QJ " After" you had all the vacuum leaks fixed and the timing set. That is what I used to go by.
I will check the throttle shaft in the morning, but doubt it is worn as this carb came off a 30,000 mile engine but you never know, huh? You can really hear the carb sucking some serious air when you take the air cleaner off,,!!
Man, I am so disappointed with the way the engine is running now.

[Restrorob]

Well....30,000 on a 20+ year old carb = a lot of sitting around, That's not good for any carb. I would have rebuilt it before install just to eliminate unforeseen issues, The cleanliness of the outside means nothing....

[joebuick]

Hey Restrorob, As a fact of the matter, I had dismantled, cleaned and blew out and checked all passages before I installed new kit even though everything looked like new. Even new float. I took the carb off the truck this Am and I'll be danged, the throttle shaft has .090 slop on the left bushing and .062 on the right bushing. I was going to go ahead and remove the throttle shaft and make some new bushings on my lathe but have not been able to find a really small torx bit to remove the primary butterflys. Guess I'll have to wait til this weekend and go to Sears in Roswell and hope they have one.

[joebuick]

Hey Guys,, I'm still looking for a small torx bit to remove the primary butterflies on my QJ so I thought I would try something else. I advanced the timing to 12* BTDC and then re-adjusted the air adjustment screws and the engine smoothed out great. We drove up to our place in the mountains this weekend and was pleasently surprised with plenty of power pulling my 16 Ft trailer loaded with four 4 wheelers and had no problems getting to "the ranch" at 8,200 elevation. Most of all I was really pleased with 14 MPG for the round trip of 200 miles,,,,!!! YEAH,,,!!! I'm hoping 16-17 without a load,,,,,? I'm still going to replace the bushings in the throttle shafts,,,when I find a small enough torx bit.