Just purchased a 1972 Datsun 240z from a Dealer in Colorado where it is cold. The car was shipped to Panama, Central America where the temperature is 32 degrees Celsius (Hot Weather). Anyway, i had to remove the thermostat as it was taking the temperature needle more than half way. The car Works perfectly and mantains the needle at half of the temperature gauge for the first 25 minutes. After that time lapse and whenever i stop at any intersection light the RPM starts to drop to 600 RPM with the intention of stalling, so in a rush of not being dumped in the road i drove to my house and kept the car in idle for 2 minutes when it finally shut down. Could this be a carburetor adjustment problem even though the seller advertise them as fully rebuilt? the front 3 spark plugs have turned black, the rear 3 spark plugs are clean. As background information the seller did the following changes in the car:

◾PerTronix Ignition Kit with new coil

Electric fuel pump

◾Recent rebuilt Engine

Recent rebuilt 5 speed transmission from 280Z with new Center Force 1 clutch with stainless steel clutch hose

New Twice Pipes Exhaust

60-Amp Alternator upgrade kit

New fuse box

New Fan belt with new upper and lower Radiator hoses

New 3 row Aluminum Race Radiator

New Plug Wires

New Thermostat and oil pressure sender

New brake system with stainless steel brake lines

New struts

Rebuild Carbs

The engine and transmission have less than 6000 miles on them. The following is a list of upgrades or modifications made to the car:

New Datsun L24 motor has crank and rods from a L26, special oversized 84mm flat top black coated pistons from D.L. Potter Engineering with E88 Head and Far 311 New Race Cam.

Please be advised i have not changed the spark plugs, oil filter and oil to this car since i received it last week. I just want to be sure how to tackle this stalling problem before i do a tune up. It is really weird the car begins to stall after it has fully warmed up.

Congratulations on your purchase and welcome to the club. Sounds like the front carb needs some attention.I don't know how knowledgable you are about SUs but there is plenty of info about them on this site. Do some research and then you will be able to diagnose the problem. Possible things to check; stuck nozzle in the choke-on position, float level, mixture wrong, etc. Do a complete tune-up before you attempt to balance the carbs and keep asking questions. The club members love to help.

Mark in Portland

Congratulations on your purchase and welcome to the club. Sounds like the front carb needs some attention.I don't know how knowledgable you are about SUs but there is plenty of info about them on this site. Do some research and then you will be able to diagnose the problem. Possible things to check; stuck nozzle in the choke-on position, float level, mixture wrong, etc. Do a complete tune-up before you attempt to balance the carbs and keep asking questions. The club members love to help.

Mark in Portland

Thanks Mark. Do I need to purchase a Carburetor Synchronizer to accomplish this or can i do it manually? Your assistance is highly appreciated.

Uni-Syns are cheap but it is possible to balance Sus by ear using a piece of hose and equalizing the pitch [note] of both carbs. I've done it succesfully but I was never sure I had it right until I dbl. checked the balance with a Uni-Syn.

Mark in Portland

Being from Colorado when I brought a Z out to NJ when I got to a certain lower elevation I had to adjust the carbs. If it is from Colorado it is tuned for high elevation and needs to be re-tuned for lower elevation that you find in Panama. Be careful the car is more than likely running lean and with to much vacuum.