All my weirdness:, Temp problem? Gauge problem? Wiring problem? Options

[Mike Sanford]

This is long, but I'm trying to get all my car's issues in.

I have a 74 1.8, l-jet. Owned for about a year and a half. Aftermarket oil cooler with an electric fan on it in the rear. Petronix ignitor and MSD box installed since I bought the car. A few unsorted problems I'm trying to work out, don't know if they're all related.

Voltmeter and temperature gauge in what I think the PO said was an aftermarket center console.

I live in the middle of a very hot town, many of my trips are less than 2 miles, lots of stoplights. Longest trip I've made in this car is 14 miles.

In October my ECU went out. Replaced with another used ECU. The following problems have happened with both ECU's, and before and after installing the Petronix and the MSD.

Sometimes, and this will happen for weeks on end, the temperature gauge will climb to the redline within the space of a 4 mile drive. Doesn't seem dependent on ambient temperature. My solution so far when the car has been acting like this, take the Honda if I'm going more than 4 miles.

Sometimes, and this has occurred for periods of up to two months, the temperature gauge will seem normal.

Sometimes, during periods of time when the car is reading hot, and this has only happened four or five times, the temperature gauge will spike to the redline within a half mile of driving. If I turn off the key, and turn it back on, it will return to what seems like a normal reading.

Sometimes, also during periods of time when the car is reading hot, the temperature gauge will bounce up and down if my turn signal is on.

During the periods of time when the car is not reading hot, I've had trouble with what felt like fuel starvation randomly, stalling or almost stalling.

Idle is pretty random, no matter what I set the idle at. 800 rpm one stop light, 1700 the next.

Car just entered another phase of "reading" hot this weekend. Went out and bought an infrared thermometer. Drove it long enough to intentionally bring the gauge into the red. Got readings of 280-290F at the cylinder head, aiming as close as I could to the spark plugs. Readings of 180F off of the tuna can. From what I can gather, this is a fairly inaccurate way to gather temperatures. But these also don't seem like problematic temperatures. I need to drive the car to emissions this week, which is farther than my 4 mile range.

I'll wait for the wisdom of the World.