Just started driving my car, i love it, but am having problems;

76 280z auto trans. 180,000 miles.

DAY 1: drove car for 3-4 consecutive hours without incident. Car is quick.

DAY 2: after car warms up, fuel pump whine becomes louder ( i dont know how loud its supposed to be);

Car starts to hesitate, cut out under throttle. RPMS drop with hesitation. Exhaust may backfire out of tail pipe.

I though fuel pump, but backfire suggests ignition, since fuel is present?

I googled this, and came up with ignition module, or somehitng HEAT SENSITIVE like a transistor???

I'm thinking:

Ignition coil, Ignition Module (EI box?), pick up coil(s),?

Car used to spew black smoke, i fixed that by cleaning all electrical connectors. no smoke now.

Car will warm up in 15 minutes (temp gage goes to middle), but problem doesn't start until car has been running AT warm for 20+ minutes, then i pretty much have to nurse it home.

The car does has a intermittant backfire at part throttle, but not really an issue, as I just have to push the gas harder.

Any way to change transisitors in the Ig module w/o a new one? I cant afford more stuff, I still need to fix the brakes; Can I test the pickup coils, EI box, etc..??? The 76 260 has two "control boxes", right? the ECU and the ignition.

Is the heat problems related to the position of the box, possibly? ie can the box be relocated to inside car of in front of grille, somewhere where there is less heat??

This is probabaly a part that is heat sensitive from being old, I know resistance rises with temperature rises.

Thanks for any input, I want to keep driving this car but it needs to be pretty reliable (for a 33 year old car anyways).

BTW Car has brand new battery installed 2 days ago.

The outside weather was the same both days, app 70 degrees F , sunny, some breeze (basicall super nice driving weaher).

I plan to test fuel pressure this weekend. How loud is the pump supposed to be? Its not super loud, but a decent whine from right rear when warm.

Edited March 18, 200916 yr by 280ZSS

Check the connection at your water temperature sensor. If the connection is okay then check the sensor itself as per page EF-53 the 1976 FSM.