The Stovebolt Site Forums The Back Office The Greasy Spoon Getting greeat grandfathers car ready for daughter

So I have hung onto my grandfathers car for 30 years and not done much with it other than start it and move it once a year or so. Not sure if some guru's of 70's vehicles exist here.

1977 Cutlass with a 260 V8. Perfect car for a 16 year old next summer.

1. Temps go to 230. Then stalls and vapor locks.
I replaced T Stat after testing both. OE opened but not much and it didn't open till 210/212. New Stat opens well. Thought that was going to solve problem, but didn't. I dropped level of coolant so I could see flow. Used camera and no corrosion or blockages on outsides of tubes on cap side. Flows well through tubes once stat open. When temps go past 215 it is a torrent in the rad. Fan was not blowing well once hot hot. Removed and can't get clutch to lock in even with a torch on spring so I have ordered a new clutch. Not here till friday.

2. I can't seem to keep fuel in the carb?
If car sits for a day or two the bowl is empty and will not start unless I pour into the vent. Once started it is perfect. Pump is pumping well when I take fuel line off so I am unsure why it won't fill bowl when cranking. Can it be leaking back through the pump?

3. The diverter valve in snorkel never opens to allow fresh air? I have played around with the vac lines and ended up disconnecting it to keep it open. I am assuming part of the vapor locking was always chewing on hot air?

Any lost wisdom that can be passed forward?

First of all I’m not an expert but the definition of a shade tree mechanic who just happens to have a personal use shop. Now that the disclaimer is behind us…on the heating issue, I wouldn’t do anything until the new fan clutch is installed and tested. If still overheating I’d source a dirty old greasy radiator shop and have them freshen the radiator up. They will know what to do. That is if I’m correct in thinking it’s copper with a brass tank, no plastic. If plactic tank then a new aluminum rad may be called for.

Fuel, sounds like the needle/seat in the float bowl is leaking. A good cleaning and kit with ethanol friendly parts is called for.

Good Luck,
RonR

Fuel cannot leak back from the bowl of the carburetor back to fuel pump. The needle and seat are at the top of the bowl so it can't flow uphill, them down to the fuel pump.
The Law of Gravity is a law, not just a suggestion.

The weakest link in the vacuum operated heat or heat/AC system is the vacuum switch in the dash. They are 2-part diecast metal held together by a rivet (and hopeful imagination).
I have fixed one in an old Buick by replacing the rivet with a very small screw and a lock nut. You need a locknut in order to provide for the proper torque to seal the swivelling halves, but not too tight that it won't move freely.

Quadrajet carburetor, right? Early QJs had a problem with some staked-in plugs at the bottom of the float bowl leaking and emptying the bowl if the engine was not run for a few days. The fix is to peen the plugs in tighter and/or apply epoxy filler to them. There's also a plastic filler block that fits the jet well under those plugs that's included in most qood quality rebuild kits. The snorkel air valve is controlled by a thermal vacuum valve installed in the thermostat housing, above the stat. When the stat opens, manifold vacuum is supposed to be routed to the vacuum motor that opens the flap and allows cool air into the carburetor. A good thermal fan clutch is a must- - - -or just eliminate the clutch and direct drive the fan with the proper length spacer to put the fan blades HALFWAY into the shroud. Normal operating temperature on that engine is 195 degrees. That's where the thermal/vacuum valves for the heat riser and snorkel vacuum motors are supposed to work. PM me if you need more specific details.
Jerry

I had an 86 El Camino that had sat for many years and would overheat. I fought that for about two months and finally pulled the intake off and the water ports between the heads and intake at both ends were clogged up with crystalized coolant. cleaned that out and all was good.

Fast55 52 Carl and Hotrod,

Hot rod I PM you so I could send you some pics.

1. The thermal valve seems to be working now? It sits under some little tin cover in front of the stat. I got it out and replaced all vac lines. I took for a drive and it now opens.
2. The fuel inlet is on bottom of bowl front of QJ. I am not convinced its a carb issue yet with a lack of fuel. I solved many vac leaks and things are better. Will know more tonight when it has sat for a day.
3. Temps seems to have resolved. New stat and clutch seem to have done the trick. Driving around it goes to 200, but will come back to 185 ish slowly.
4. I found a plug boot off a plug which was hidden from sight. Driving before and after was no difference. It did effect idle so I know it is firing. One would think with so little HP getting a cyl back on line would make more of a difference?

Those little pleated paper fuel filters at the carburetor inlet are notorious for getting clogged and causing symptoms that mimic "vapor lock". GM tried to solve the problem by installing a filter housing about twice as long and using a longer filter element on later carbs. I believe that can be added to an early carb by doing a little tweaking of the fuel line length at the carburetor.
Jerry

Well. Going through the carb this weekend I was putting the accel pump lever back together and snap. Broke an ear off the carb that holds it.

Then I find the tubes that go to the choke are cracked open at the manifold.

Time for complete desmog I think. Maybe FI.