Please help. Anyone

[PKnFR]

Car: 1972 Datsun 240Z w/ 4-spd transmission

Engine: 6-cyl, in-line, SOHC, Carburated L-24

Last Tune Up: Unknown

Last Oil Change: Unknown

Time Car "Sat": Aproximately a year or two AT LEAST

Problem: Turns over, but will not start. (also, if I turn the key to the "ON" position, oil pressure reads high)

Additional Notes: Seafoam was added to the motor, expelling a lot of carbon build up, but due to the heat riser recycling heated air, carbon was shot back into the air cleaner and possibly carbs. Also, there is an exhaust leak between the end of the headers and down pipe.

My Question:

What should I do? Should I give it a tune up immediately? Check compression? Check distributor cap? New wires and plugs? Fuel filter? Oil change? Also, I know the car has a "safety interlock system prevents operation of the car unless the front seat belts are fastened and the gear lever is in the neutral postion (manual gear box)" according to my Haynes Repair Manual..... but there are no seat belts! :sad2: Only the release buckles, although, there is an override switch in the engine compartment.

What should be my plan of action? I think the first thing I need to do is get it to start.

ANY help would be GREATLY appreciated.

Thanks, Mike

 

[pgarner]

if the cars sat for over a year the petrol could well have went off. drain the tank and refill with fresh petrol.

if that works then change the rest of the fluids

 

[stamford]

Seeing that it is 'old school' have you checked for the two main ingredients? Removed spark plug and crank over with plug against block, do you get a healthy spark? Yes means it is getting juice so no immobiliser issues, if no then investiage cause for no juice. If mechanical fuel pump, removed pipe from carb inlet and crank engine, does fuel squirt out as expected? If yes then you may have blocked carbs or check that air can get to carbs. If no then suspect broken pump, sludged lines etc.

Have carried out a compression test?

 

[PKnFR]

I have been getting my funds together (keep in mind I'm a highschool student and only get 11 hours of work a week). I have yet to do a compression test (there's simply too much snow and it's too cold out there), but I plan to at the first opportunity.

What does a higher compression mean? And what does a lower compression mean? (just in case)

Then I plan to check what stamford suggested. Just for clarification, what do you mean exactly by "crank over with plug against block"? Are you saying hold the plug against the motor?

Also, there is very little gasoline in the tank, so I am taking your advice on draining it. The only problem being... did the '72 use leaded or unleaded gasoline and what octane should I use??

I heard using unleaded in a leaded motor wears the valve seats, and leaded in an unleaded motor causes clogging.

 

[HDi fun]

Compression will generally be either correct or low. What you're looking for is even-ness across all six cylinders. If you have low compression then there is either a head gasket fault, a valve sealing problem or worn compression rings.

Two adjacent cylinders with low compression would suggest head gasket to me.

 

[jarrus]

On the money there HDI,

Compression should be within 10% of each other, if not there there is a fault as discribed above.
I would reckon old petrol/gasoline is most likely the cause and I would try that route first.
Using the highest octane avaliable wouldn't hurt as it's less of a desaster than using one that's too low.