Engine has rough idle, will not stay running for 20 seconds.

The problem began with the car having distinct lack of power, upon driving the car home the car died and would not restart. The car would turn over, but not stay running or start. Pumping the gas and turning the key resulted at best in a very slow idle that would last less then 10 seconds before sputtering and ceasing.

Upon inspection of the engine two vacuum lines were damaged, both coming from the carb, these were replaced. The fuel line was inspected and was found to have fuel in it. The fuel filter was taken out and examined, it is also working properly. The spark plugs were examined and changed with new spark plugs. These spark plugs spark properly meaning the Automatic Shutdown Relay and computer was working.

Attempts to get the diagnosis from the car was prevented by an unknown issue with the instrument panel. Believing the problem to be a dead 'Power Loss' light the bulb was replaced, but it did not immediately turn on with a key cycle. Upon the battery being recharged, disconnected and then reconnected the codes were able to be obtained. The process for obtaining codes must elude my Haynes manual instruction because getting these codes has been through repeated attempts to start the car, with no codes being displayed first.

The timings were checked and reset to TDC, they were not off, but during part of our working had been adjusted accidentally, this problem has since been corrected and the engine does combust, but has not fixed the idle problem.

Error codes which returned are now point to the MAP sensor, with no difference in pressure for the sensor and the Throttle Position sensor voltage being too high or too low. The Throttle Position sensor was replaced, but did not solve the problem.

As a DIYer, I have quite a few tools at my disposal, a dry compression test yielded PSI of 100~ on all cylinders and 120~ with wet compression test on the cylinders. I do not know if this is the source of the problem, mixed research on the matter suggests it should run, but others point out that it should not run. Given the car is capable of combustion and idles roughly for a period before dying, I hope the details provided will help you in identifying the problem. Thanks for reading.