viper771

Hey everyone! I have a chance to work on the Starfire since it has been a bit warmer here in Ohio. I am going to take the heat riser out and check it since I think that is causing my overheating problem that I STILL have. But I wanted to see if anyone can point me in the right direction for a carb book or tune up book. I wanted to replace a few gaskets in my carb but I have NEVER taken a carb apart before..and I didn't want to mess anything up. I wanted to change out the rotten rubber plunger and the air horn gasket (since that is weeping) or anything else that is leaky. The carb was redone rather recently but I think the ethanol in the gas is eating the gaskets up. Since I replaced all rubber gas/tranny lines, put in stainless main gas line, and got a rebuilt fuel pump, I haven't had any fuel leaks. I also wanted to see if there was some kind of tune up book because I was told my car may be running a bit too lean, which may cause the over heating. Any info would be great! I mostly see stuff for the quadrajet but not a whole lot on the 4jet. Thanks in advance!

justinj

http://www.newagemetal.com/pages/Oldsmobile/index.html

The carb manual for the 4gc can be downloaded from that link. As for general theory and tuning, the principles should be pretty similar to the Qjet.

Some of the carb kits (like the one from Fusick) don't come with the rubber fuel plunger for some reason. So it's possible your rebuilder just left the old one on.

The NAPA brand kit does come with everything, though.

frankr442

Carbs aren't bad to rebuild. I can't speak to your year, but I did my first Q-jet by following the GM service manual step by step. One tip I can give you, work over a white towel duct taped to the bench. If anything is dropped or falls out of the carb, you can see it and it won't bounce or roll off the bench. If your work area is anything like mine, you'll never find it.

viper771

Thanks fellas! Yeah, I do remember someone mentioning that the rubber plunger was not included in the Fusicks rebuilt kit. The outer look of the carb is great and still has the newer green paint on it (except where some of the weeping gas messed it up). The link will REALLY help! Here soon once I get some impact wrench sockets I will attempt to take out the heat riser and just take the flap out itself to see if that changes anything. I will keep everyone updated

Nimrodinder

Hi viper771. Interested to see how u go with yr 4gc rebuild. I think I've got the opposite problem... Running Too rich. I too know little about carbs but I figure the black sooty exhaust stains on the concrete is a sign of unburnt fuel. And the fact that I get only 8.6mpg cruising (not thrashing) long distance. My mate with a 60 caddy with 390 high comp engine gets 13mpg. I may be wrong but it seems adjusting the fuel/air mixture affects only the mixture at idle. So maybe the jets are wrong in it. Would appreciate u tell me what size jets are in yours when u get it apart please. Thanks

viper771

Sure I can see what I can do. I don't have any idea when it comes to carbs. I am just trying to get it running good enough while it still has single exhaust and other issues lol I won't know more until I take out the heat riser value that is stuck shut (I am quite sure that this is what is causing my overheating problem).

How do you measure the size of the jets anyway? I am still learning the mechanical stuff about cars. So far been working on changing out the miles of vac tube and refurbing the heater/summer controls. Keep in touch! I will let you know once I know more lol. Is that your white starfire in your avatar picture?

Nimrodinder

actually now that you mention it no, its an identical one i found to photoshop the wheels onto before ordering them. I should change that pic. photos of my car can be seen down the page at this link
https://classicoldsmobile.com/forums...ngs-found.html

So do I understand you correctly that your starfire has a single exhaust?
I agree, that stuck riser valve wont be helping your overheating problem but it also must be killing the performance of the motor too. Mine was cracked so I took it out. Doesn't get cold enough where I live for it anyway. I'd remove that before doing your carb rebuild. I'm told there should be some numbers on the jets to identify their bore size. I'm just not sure what size they're meant to be.

viper771

Yeah, somewhere down the line someone converted my Starfire to single exhaust. It was like that when the previous owner bought it. He was going to part it out (it is a true california car) for his 62 vert project but decided it was too nice to hack up. Fixed it up a bit and sold it to me. The only reason we could figure that it was converted to single exhaust was to save money. I actually haven't had mine on the road yet since I bought it last summer. Trying to work out some bugs so far..like very sensitive brakes. The brakes were all redone before I got it but I think they are a bit too sensitive. I have to barely tap them, otherwise I go through the windshield lol

Yeah I do plan on getting rid of the heat riser. I just haven't gotten to the point of ordering new gaskets that go on either side of it. I will either just take the butterfly valve out or try to find a spacer. Hopefully I won't break any studs when I take it out.

I will keep an eye out on the jets and let you know. It is always an adventure on this car! I will check out the pictures of your car too

Nimrodinder

the brakes are pretty good on these Starfires despite being only drums. You may need to get the drums skimmed, but first squirt the shoe linings with brake cleaner as there might be some oil residue on them. then try driving and braking again. also, check the brake drum linings are the same thickness on the front wheels otherwise it'll pull to one side as the shoes contact at different times.

I had a spacer laser cut at an engineering place to replace the heat riser valve but maybe try without it first. A friend of mine with a 60 caddy took his valve out and simple bolted the exhaust and manifold flanges back up. I didn't try that. Also if gaskets are not easy to come by just use exhaust silicon sealer in a tube. worked for me, easy and quick.

viper771

The guy who redid the brakes put in a new aftermarket master cylinder and booster (looks like the kind you can get for an impala). I haven't been able to determine if my brake pedal comes up too slow either. It is either the booster is bad, brakes need adjusted, or the aftermarket booster rod to brake pedal is too long. But I will take a look at the shoes and what not to see if everything is squared away. I don't think the previous owner did the stuff himself, he took it to a shop to get a lot done, according to the paperwork. So who knows if stuff is right or not.

As for the heat riser spacer... I know they make the spacers for impalas... I wonder if they would be the same? I don't think I have the spacing to just bolt everything back together without something in place (being a single exhaust and all). I think fusicks sells the gaskets but I didn't think of the silicon sealer! So at least there is a plan B. Thanks for the info! Hopefully I will have some time to actually work on it and maybe get it on the road this summer.