Back Story: I recently took my Geo Metro on a road trip. 2700 miles of road trip. The first 800 mile nothing happened. Then going up a hill it died, dropped from 75 mph to 55 mph then the engine kicked back in. It then did this on the next hill as well, and the next. After that it was fine even on the hills. On the return trip it happened once again on the same hill as the first time, then 700 miles later it happened again this time at a stop sign on small hill. When I was about 60 miles from home it started dying every or 6 miles.
4 cylinder motor
Details of stall:
No sputtering before it dies.
Electronics, such as radio still work.
If I am at low speeds 50mph or below, I have to pull over and shut off completely (sometimes wait a minute) then restart.
Things I have checked or replaced:
The air intake temperature sensor was the only computer warning - Replaced
Fuel filter - Replaced
Distributor cap and Rotor - Replaced
Ignition control module - Passed tests at Autozone
Spark plugs and cables - Replaced and gapped properly
Fuel Pressure - I setup a gauge to monitor it and took it for a test drive. It maintained 20 psi when idling, 25 -30 psi when driving, and 20 psi when it stalled.
Question: So far I have been thinking it was electric because of the lack of sputter. Am I right in this assessment? If I am what else to check? If not, what should I be checking?
Right now, I am planning on replacing the ignition coil with one from a junkyard. New would cost $95, junkyard is $7.99