70 Z goes great for about 4milies then dies

[kirkE]

Ok - I am stumped, new points, dist, coil, cap, new fclear fuel filter with gas drained and lines blown out. Car will idle for hours, drive 4 to 5 miles after it reaches temperature and it starts to bog and then dies. After I drained the gas it actually drove for about 10 miles around town and then did it again. Wait 10 min. and then it starts and maybe makes it home or dies another time. I have fuel, I have voltage at the points? I have replaced the wire from the coil to the points on the dist. Had my turn signal and combo switch rebuilt. Could it be the starter switch on the back of the ignition key switch. I have pulled and tugged on the wiring but can't make it quit. Any ideas

70 240z just rebuilt engine, runs like a champ --- just before it dies..

[240znz]

Did you blow out the fuel return line as well?

It either electrical or fuel related right. Once it has died, does the starter motor turn over? Do you have electrics.

Not as simple as a stuffed battery and alternator charging circuit fault is it? Happened to me before. Battery has just enough charge to run everything for a bit then dies. Wait a while until the battery recovers then it is a OK for a short while.

[Nigel1943]

I'd say this is fuel related. Dont know if you've ever had your tank cleaned but 35 year old tanks do tend to "crud up" blocking the outlet when the crud moves about. Other than that is your pump working ok?

[beandip]

When you replaced the points did you also replace the condenser? This could be at fault when it warms up it can fail. When the engine dies have you checked the fuel filters to see if there is fuel in them. This will let you know if the pump is working. Just a thought. Gary

[Fun_in_my_z]

I'd say this is fuel related. Dont know if you've ever had your tank cleaned but 35 year old tanks do tend to "crud up" blocking the outlet when the crud moves about. Other than that is your pump working ok?

I think Nigel hit it on the head. I bet you got trash in the tank

[beandip]

When you replaced the points did you also replace the condenser? This could be at fault when it warms up it can fail. When the engine dies have you checked the fuel filters to see if there is fuel in them. This will let you know if the pump is working. Just a thought. Gary

[DaveN]

Kirk,

I had exactly the same symptoms with my '72 shortly after I bought it. The problem was crud -- a mix of water, rust, & bacterial slime -- in the tank repeatedly clogging fthe fuel filters and lines. Getting the tank cleaned fixed it.

[2-4-T-Z-MAN]

Ditto to trash in the tank answers. I had a small piece of plastic floating around that would get sucked into the pickup and then I'd pull to the side of the road. Seconds latter she'd start up and repeat.

[Mat M]

I just found the pickup tube to be corroded on mine. ;o(

Radiator shops will boil the tank, then you can POR-15 the thing and not have to ever worry about it again!

[JimmyZ]

I'll take a swing...

How's your fuel filter?? Try changing the filter after it dies. See if the restriction in your fuel rail is plugged. (The small opening on the return end of your fuel rail. Try blowing air through the fuel rail with the lines removed. (remove and plug your carb lines for this) If you have on, take a siphon sandblaster's pickup tube and attach it to the supply line.(After the fuel filter) Run some air through the gun hold a rag over the discharge end and see what kind of crap ends up in the rag.

Did you take off the carb float bowl tops and check the needle valves?

I once had a rusty tank which clogged the filter every few miles. I removed the tank, dumped as much crud out of it as I could and bought some time/functionality before restoring the tank.

Here's a fuel tank refurbishing page I made. It might help. Nice pics at bottom of page.

http://warbuddies.homestead.com/gastank.html

Cheers

Jim

[kirkE]

I did have the tank boiled out and coated. But, that said when I drained the tank the drain plug was coated over with this rubber type coating. It got me thinking about the pick up tube and so I dropped the tank ( a ton of fun by the way) and made sure I could at least get air through it. It sounds a bit strained I must admit, but my clear fuel filter shows gas. I did not blow out the return fuel line, so I will try that. I can also say that now that I drained the tank - the car will run on 3 cyclinders and not quite die. Hmmmm.

[GreenZZZ]

Did you take off the carb float bowl tops and check the needle valves?

While your checking the needle valve, between the inlet tube of the float bowels and the float bowl check needle valve is a barrel wire mesh filter. I had this thing jam up on a Z once. I've seen people remove these. Mine are installed.