When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
ok, so now that I've been exposed for not being too bright, not seeing the remanufacturing sticker on this carb, guess I should press on. I still think rebuilding it would help with at the very least cleaning it up and replacing any worn parts etc..
But, I can't tell if it has already been re-bushed. If it has, should I skip that part? I tried checking for play on both shafts and it seems there is a some play, fifteen or twenty thousandths at least, hard for me to tell with the linkages still attached. Someone indicated it should be very little, which I think means less than that. Maybe I will need bigger bushings?
Sorry for the stupidity earlier, can't actually promise there won't be more though.
And thank you again MDchanic for pointing it out.
As for the bushings, pop off the throttle cable and the spring and see how it feels then.
0.010"-0.015" doesn't sound huge, but it's more than it should be. If you've got the toys, it's something you can fix, but it's not essential at that level (My opinion, at least - I'd be interested in what others have to say).
Hey Jeff - just to give you some positive thoughts going forward, as cruddy looking and hesitant-laden your Quadrajet is now take a look at these before and after pix. They should give you some inspiration. You got all of the tools - now do it!!!
Before -
After -
Not perfect looking but 100% improvement on acceleration and overall responsiveness.
If you need to make changes later, you can always buy jets and/or needles and make incremental adjustments. They're cheap (see the link I posted above to QuadraJetParts.com).
NEVER drill, file, or sand these parts (there are some experts who can, but leave that to them). You'll only ruin them.
- Eric
Jeff this guy has given some great advise on his post in this thread pay close attention.
thanks dalilama, I needed that.
I will go on with this, hopefully make things better. I've had cold idle issues since day one, also seems to run rich most of the rest of the time. Once it gets warmed up, the car runs pretty well, but I know it can be better all the way around.
I've done dumber things than not notice a sticker.....
wr1970: I know.
Rebuilding it is a good idea but it probably won't fix your cold start issues. The choke coil may be set a bit too tight but I am betting the choke pull off isn't opening enough. That is what I like about the later carbs, a screw driver adjusts it. I am betting linkage needs bent on the earlier carb. There is probably a GM method, follow that, sure Joe or Chris will know it.
thanks dalilama, I needed that.
I will go on with this, hopefully make things better. I've had cold idle issues since day one, also seems to run rich most of the rest of the time. Once it gets warmed up, the car runs pretty well, but I know it can be better all the way around.
I've done dumber things than not notice a sticker.....
wr1970: I know.
Sounds like it is lean actually if it runs good only warmed up. Factory tune is lean also and designed for 195 degree thermostat and a restrictive closed single snorkel air cleaner. This is why a factory jet rod combo in an Olds Qjet must have a proper re-calibration to run well with cooler less restrictive air and lower operating temps typical of any normal rebuilt old car these days.
I would assume being in Colorado, cars don't get as much air as at sea level. Anyway, I will attempt to address any other issues after I've properly attended to the carb.
What I mean about cold start problems is the fast idle didn't seem to work at all. So, linkage and choke adjustments may be in order along with the carb rebuild.
Sorry, I misread that that it was rich on start up. It may need the fast idle speed set up and more tension on the choke coil. Make sure you get a new float if it is running on the rich side.
I would assume being in Colorado, cars don't get as much air as at sea level. Anyway, I will attempt to address any other issues after I've properly attended to the carb.
What I mean about cold start problems is the fast idle didn't seem to work at all. So, linkage and choke adjustments may be in order along with the carb rebuild.
True on altitude, GM did make high altitude Qjets for the trucks. I recall tearing into a few and found odd size 63 jets instead of something in the 71-74 range but also a very rich 36 rod instead of say a 40 something rod.
True on altitude, GM did make high altitude Qjets for the trucks. I recall tearing into a few and found odd size 63 jets instead of something in the 71-74 range but also a very rich 36 rod instead of say a 40 something rod.
As emissions control requirements became more stringent, automakers were forced to develop high altitude versions of engines for specific models, with unique jetting and timing (at least until O2 sensors and feedback controls became the norm). The problem, of course, came when these cars traveled to sea level and thus ran too lean.
so it begins. Having already exposed my ignorance, a little more won't hurt I guess.
I took your advice MDchanic, as to pulling the throttle cable and spring, the secondary shaft seems to have less than .010" play, and zero on the front (primary) so maybe I won't need to re-bush. Now the dumb part. I removed the cable, vacuum lines, fuel line, and four half inch nuts which all seemed a little less than tight to me BTW, but the carb seems to be held by something. I can get a bit of play but don't want to force it. The Ruggles book is great, but it does assume one knows more than I about this. Any suggestions?
Thanks.
Unscrew little flare nuts that hold choke air tubes to choke unit.
Using TWOflare-nut wrenches (the kind that are like box wrenches, with five sides and one missing side), remove the fuel line from the filter chamber - Hold the filter chamber wrench steady while sharply tapping on the fuel-line wrench with a heavy hammer, don't just pull hard on the wrench right off the bat. When the nut starts to turn, you can pull on the wrench normally.
Remove the four screws (bolts) that hold the carburetor to the intake manifold.
Remove whatever I forgot to tell you to remove.
Remove carburetor.
I copied this from another thread. On number seven, I have nuts rather than bolts. Other than #8, I think it should come off. No service manual here unfortunately. What am I missing?
if youve removed the 4 bolts circled (2 each side) and any hoses, cables, and choke attachments it should come right off.
the service manual has a great section on carb dis and re assembly as well as all adjustments.
additionally if you have a hot air choke you can convert to electric chke easy and cheap, i just did that because i have an aftermarket intake w no hot air provision.
I just got some parts from this seller on ebay and im happy w them.
thanks for the replies. I have removed the four nuts, but am hesitant to apply too much pressure taking the carb off. Maybe I'm just being too careful, it does have some up and down play, seems uneven though. I only have a few hours a day during the week so tomorrow I will try again.
Thanks again.
Why would someone use allthread and nuts rather than the correct bolts? Is there a logical reason for this? I'm thinking about putting the correct hardware back when I'm finished with the carb.
Eric, I will apply more up pressure, it's not actually stuck like one would think. I have taken the heads off a motorcycle before as well as other gasketed surfaces, this really seems different. But again, I may be just being irrationally careful. Still, appreciate all advice from you guys. I'll check in later this afternoon.
Based on this previously posted pic from you, you've got a big spacer in play here as well, and it looks like someone replaced the bolts that are supposed to be there in the front with some threaded rods and nuts. Probably since the spacer did not allow the original bolts to reach the intake.
2X on the whack with the wood/hammer (and maybe some WD-40 shot down the threaded rods first as well). While you are doing it, see if you can apply some leverage under the spacer.
alrighty. Got the carb off, left the spacer on and it appears to be plastic and I have some questions. What is the purpose of the spacer, better fuel/air mixing maybe? Should I leave it on? If I take it off to clean it up I'll need another gasket. What else?
Here's a few pics, not sure what I need to show here. In one picture you can see the choke linkage is binding, not sure of the cause or if I can bend something a little.
Sometimes spacers can make an engine run a bit better under certain airflow conditions, but people also use plastic or fiber spacers to reduce heat transfer, usually in an attempt to solve problems that are actually being caused by other things.
To me, a spacer like that would be a strong argument in favor of a rebuild.
so, as I said, the spacer stayed on the intake manifold. What are the pros and cons for leaving it there, taking it off and cleaning things up, new gasket, re-installing it, or taking it off permanently?
so, as I said, the spacer stayed on the intake manifold. What are the pros and cons for leaving it there, taking it off and cleaning things up, new gasket, re-installing it, or taking it off permanently?
A phenolic spacer like that can serve two purposes. It insulates the carb from engine heat, potentially helping with percolation and hot soak problems. It can also be used to change the tuning of the intake runner length, which may or may not result in a small performance increase at certain RPM ranges. The performance benefit or lack thereof will vary based on the specific car, engine, mods, and how it is used. Only back-to-back testing on the track with your specific combo will prove or disprove the benefit.
If you do decide to keep it, pull it off and replace the gasket between the spacer and the intake. This avoids having to pull the carb off again after you find that it's leaking.
sounds reasonable. I will have to find another gasket or make one I assume. Although this car has some mods, it won't be used for any kind of racing while I own it so I guess I'll take it off and clean it up, and re-use it. The car almost never goes over 200 degrees according to the gauge so I won't mess with changing the spacer situation.
Thanks guys.
I should say it never has gone over 200, in the couple years I've owned it.
Last edited by jeff in colorado; May 19th, 2016 at 04:33 PM.
Reason: clarity.
That is the Mr Gasket 1" 4 hole spacer, it uses two of the second 4 hole gasket Joe is showing. One between the spacer and intake and one between the spacer and carb.
thank you Joe and olds 307. I'll do this right and pick those up today hopefully. I also need a smaller than T10 for the secondary... crap I forget the name. Anyway I tried the smallest torx I have and it's too big. Did get the choke assy off and I'm close to taking the air horn off, getting into the nitty gritty this afternoon.
March 22nd, 2016, 04:39 PM
