New to the site and classic Oldsmobiles.

I just bought a 1969 98 and has what appears to be the original Rochester quadra jet.
It's been messed with and not sure how well it is working and I'd like to replace it. Any opinions on a good replacement carb?

 

A quality rebuild of the original is the best option.

I would recommend a new carb only if the original was damaged to the point of being useless.

 

Post the model # of the Rochester Quadrajet. It may or it may not be the correct carburetor for your car. IOW, a PO may have made a swamp w/ carburetor not appropriately designed for your vehicle. The model # is located on driver side towards back of carburetor. Post that model #.
Quadrajet carbs were excellent carbs during that era. They make rebuild kits ($50 - $85), often times a simple rebuild kit (which you can do yourself) is all that's needed.

 

Thanks. Will do.
it has definitely been altered by the PO. The choke doesn't close, he had it locked in the open position, and I'm not even sure the secondaries are working. It been tampered with bit not sure why.

If it does need replacement, is it best to find another quadra jet? Or are there other replacements that are recommended..

 

Stay with the exact by # Qjet if possible. All of the hoses and linkages will fit properly. It should also be a good starting point from a tuning perspective if you wish to improve performance.

 

Rochester Quadrajet carbs were designed for both specific model years & specific engines. Aside from various linkages (which can appear & are often not too dissimilar), the idle circuit (which is NOT specific to engine RPM at idle), is active throughout the range of operation i.e. idle, acceleration, cruise & WOT. Albeit, your best choice is a Quadrajet Model # designed for your vehicle.

 

Post some pictures of your carb. We may be able to diagnose some of your issues just by looking at the pictures.

 

Hopefully the PO didn't do any permanent damage to the carburetor. Does the car run?

 

A guy named Cliff Ruggles ( USED TO HANG OUT ON THE FORUM "CLASSICAL PONTIACS". He rebuilds them and tunes them to perfection. when I had mine done it cost me $225 + ship. Better if you DON'T BUY one of the "Generic" rebuilds !

 

Cliff has retired from building carbs, but he still sells parts. There are several Q-Jet specialists on Facebook that do custom builds.

My vote is for the Q-Jet. Either rebuild yours with the proper parts, or buy one already built and calibrated for your application.

 

I Wonder why it's got TORX screws holding it together ? they didn't use them in 1969 that I've ever seen .

 

Exactly where did you find Torx screws were holding it together?

 

can't find it right now, but someone had posted a picture of what is supposed to be an original W30 carb, with a picture for $500. cannot find it now !

 

You realize this post pertains to an Olds 98?

 

I know. How i ended up seeing that I cannot tell you. must be a "different link" by someone. I know I wasn't looking at parts for sale.

 

Yeah, this site has some type of "view similar posts" feature that is irritating. I disabled it. I think a lot of confusion and old posts coming back up are caused from it....

 

Thanks for all the feedback everybody. Here are a couple pictures of the carb. I just purchased the vehicle and this is how the carb was when I got it. It does idle well runs well does not start without starting fluid.
I am not exactly sure what that screw is doing by the vacuum diaphragm. I definitely could use some guidance here thank you

 

There is no reason to replace that carb. Rebuild it, adjust it properly, and possibly replace the thermostatic choke coil.

 

Pull that screw out and see if the choke works.

Looks like some type of repair has been done at the fuel filter inlet nut.

 

If you are talking about the screw in the last photo, what does that have to do with the choke? This is a divorced choke, which is in a pocket in the intake crossover. You are correct about the inlet repair. This is unfortunately all too common. A helicoil repair allows you to use the OEM inlet fitting and lose the adapters.

 

It looks like there is a screw or small bolt vertically jammed against the fast idle cam.

 

The vacuum hose to the front vacuum break may be too long and restricting vacuum to the diaphragm. I would shorten the hose and check diaphragm operation. Next up is to remove that bolt that is jammed into the fast idle cam. Then check fast idle cam and choke operation and perform tune up adjustments - point dwell (if using points, use dwell meter), ignition timing-use timing light, idle mixture-use vacuum gauge, fast idle then curb idle speeds-use tachometer.
Can you post a picture of the right (passenger) side of the carburetor? I'd like to see the choke assembly.

 

That would most likely explain why you can only start the car w/ starter fluid since the choke is inoperative. As suggested by Dynoking:

Do you have freedom of movement of the linkages w/ bolt removed?

 

Agree...I posted the image w/ arrow to highlight the bolt for Joe.

 

In the first pic there's a green wire with a yellow crimp terminal on it. Where does that go? It'd be a good idea to re-crimp that wire and use heat shrink on it.

 

Read my question from Post #2. What is the model # of this carburetor?

 

Thanks again!
I'll take that screw out, and shorten the vacuum hose this evening after work.
The green wire just a ground of some kind. I'll check what it runs to...

 

Exactly Norm. Without me under the hood I'm guessing that the choke pull off function of the front diaphragm is inoperative. I also suspect a weak choke thermostat, disconnected, or damaged choke linkage issue.
I can't help but feel some basic restoration of the choke system will restore proper cold engine starting and operation.
The evil that some people do to a carburetor should be illegal. If that carb was a animal someone would be in jail.

 

Yep forgot to take the pic of the model number. I'll get that tonight as well

 

Fully agree.

 

If you're talking about the last photo....that's a bolt in that hose, not a screw.

Could be our one day to have fun w/ Joe (maybe). Now get off the lawn you kids.

 

As mentioned above, Cliff isn't rebuilding carbs anymore however he offers the best rebuild kits out there.

I've done a few myself but for the last one I used John Herald Jr. to rebuild it. It needed shaft bushings and he has the stuff to do that. I'm very happy with it.

 

John also has the helicoil tooling to repair the inlet fitting threads.

 

So just spoke with the PO and he said the thermostatic choke coil is not working. Everything else should be fine, supposedly.

Is that something that can be replaced easily?

 

Did you happen to ask him about the bolt wedged into the carburetor next to the high idle cam?

 

One bolt and the choke coil comes out.

Presumably to wedge the choke open due to the non-working coil

 

He said that is why that bolt is jammed in there

 

That would make sense....

 

Ya really have to (NOT) hand it to some folks abilities to fix an issue. Holy Guacamole.

 

Starting to make sense to me now. I was not familiar with the thermostatic coil. Is anyone know a source to replace it?