Lbiasotto

Hi Guys,
First time long time. 1971 Cutlass SX convertible. 455 stock with G heads. No AC. Stock quadrajet rebuilt by sparky, 3 row radiator with shroud, 4 blade direct fan (no clutch). 16# cap. Pertronix hei.

Car starts and runs great, except when at idle for 5 minutes or more after car has been run (or in traffic). Then it stalls when you hit the accelerator and wont start for 20 or 30 minutes. Floor it and still wont start. Cranks fine. After the wait. Starts right up perfectly.

No temp guage but using an IR meter, I get around 225*off of the thermostat housing (painted and blue tape) in about 5 minutes after driving (car in park still running). I get around 205* immediately after putting it in park.

I also installed a phenolic 1/4" spacer, and replaced 180* tstat for a 160* with no change in symptoms. Checked radiator with the IR and it was pretty uniform with the top being warmer than the bottom.

I have read a mess of threads on this with no clear answer. She is definitely running too hot and I am guessing even with the 1/4" spacer I am getting percolation of the ethanol lased fuel.

I tried spraying starting fluid in the carb after it stalled and it fired. Pretty unscientific but I am guessing this points away from a spark issue.

However, my first question is regarding the fan. This car was hit in 73 and I assumed what I pulled off of it when I restored it was correct. But now I wonder. Could adding a 6 blade fan be enough to cool it down? Should I go to the clutch version of the fan? I basically cruise this car in the fall and spring or summer evenings and it has had this problem since I put it on the road. Only now with the IR meter could I tell it was hot.

Thank you all in advance. This place is a great resource.

Fun71

My engine has a thermostatic clutch with a 6 blade fan and it keeps cool during Phoenix 110+ summers, so I would think a similar setup would help yours to stay cooler.

Lbiasotto

Although I still may need to change the fan, I now have the temp problem under control. That's the good news. Bad news is it still will not start after shut down when idling for 10-15 minutes. Does not seem flooded. Still seems more like vapor lock.

Regarding the temp. I checked the timing. Timing was fine, however there was no vacuum advance once the car warmed up. The vac line to the distributor was bad. Replaced and the advance worked and brought temp down to about 190 after 15 minutes of idle. Huge improvement.

Now I have to check vacuum on the carb. The old DCVS was bad and now there is a 3 port version installed. Anyone know the correct set up for these 3 port switches? I will do some research along with trying to gain an understanding of how the vacuum lines are supposed to be set up to the carb. My quadrajet has a plug on the vac port on the back. this is not consistent with what I read in the manual but since there is not a 4th port on the new DCVS, I don't know if its correct. Any thoughts are appreciated?

Fun71

The valve itself should be marked with which nipples are for what. Marked as in molded in lettering. The one in my tool box has from top to bottom:
D
C
MT

Which I assume means:
(Distributor)
(Carburetor)
(Manifold Tap)

Lbiasotto

I put on an extra pair of glasses and could read them. They are set up correctly. Thank you.