I have a problem with my 240z

[chize 24]

Well, the car has sat in the garage for around six years. I parked it to restore it, but I never quite got around to fixing it until now. The car is backfiring and I don't have any throttle response. I changed both of the filters and cleaned the fuel pick-up. The fuel-tank appears to be clean, but I'm still having problems with it. Blue smoke is coming out of the tail pipe, but the spark plugs are all firing. What can I do to fix this problem?

[=Enigma=]

Sounds like the car is running very rich. Make sure the fuel nozzles arent stuck in the down position and that they can travel freely when operating the choke. It might be a good idea to pull the carbs off and do a good cleaning. If you disassemble them, do them one at a time to you don't mix up the parts.

[chize 24]

Thanks . I'll try this tomorrow.CHIZ24

[chize 24]

Sorry for the double-post, but I'm still having backfiring through the carbs. I've tried cleaning the carbs again and everything seems to be working properly on those. I went in all the way on the mixture and went out 2 1/2 turns. All the other settings are correct and I played around with the mixture, but it's still missing and backfiring through the carbs. The spark plugs are carbon fouling. I cleaned the distributer cap and roder button. Points seem to be fine and I even bypassed the fuel tank. I'm going to need a lot of help with this one. What should I do?

[MikeW]

Did you set the timing first?

[chize 24]

No. Can the timing be off that bad?

[MikeW]

I don't know how much the timing might be off; it may well be fine. The point is that you should make sure that the timing is right, the points and valves are adjusted, etc., before messing with the carbs.

[ezzzzzzz]

I beg to question the running condition when you parked it? Timing nor anything else would change unless gnomes snuck into your garage during a drinking binge. Backfiring through the carbs is typically indicative of two things... lean conditions or timing issues. Are you running six year old gas??? What did you do to the vehicle prior to attempting to start it after six years? Fouling plugs indicate a very rich fuel condition or failing ignition. If you're sure the carbs are not fouled by old fuel (sticking fuel bowl jets, sunken fuel float, stuck nozzles, etc.) then I'd look at the ignition again. Replace the plugs! The start up adjustments for the SU's are one turn in on the idle screws and 2.5 turns out on the mixture nuts. That will definately get the car running. Adjust idle rpm using the idle screws and then use the mixture nuts to fine tune for highest rpm then finally readjusting the idle screws to obtain best smooth idle rpm. Only adjust the sync screw on the linkage between the carbs at higher rpm (around 2500-3000) to sync the carbs at cruising speed. That screw up above the balance tube is used to raise the rpm's for that part and then backed out so it doesn't touch the lever. You can use a unisyn of a piece of rubber hose to sync the carbs. Yes rubber hose... just take a longish piece and listen to the intake of each carb through the hose adjusting the screws until you cannot detect any difference in sound. You'll be surprised how close you'll be when done if you were to test it with a unisyn afterwards.