Quite some time ago fellow forum members helped me conclude that I more than likely needed a new ECM (once closed loop check engine light on, engine flooding with fuel, dies, then fuel pump keeps running, unable to code flickering CE light). Now, yesterday I decided to fire it up. I had disconnected the positive terminal on the battery about a month ago as the battery was new. I reconnected the terminal, started the truck, and it then ran fine. (??) Could something possibly have "reset" during the time the battery was disconnected? I've dealt with above listed problems for over a year once I parked it, afraid to leave home with it. It just seems hard to believe it could "fix itself". But then, I'm a carb, points & condenser kinda guy. Thanks in advance for any input. -Alan-

 

Disconnecting the battery (neg cable) is a routine procedure to try and figure out the electrical gremlin problems. It allows the ecu/ecm to 'relearn' when its reconnected and to get rid of some faults. Normally only needs to be for around 30 mins but longer wont hurt.

 

So....... Maybe I lucked out (I hope)?

 

^+1 on the B- cable disconnect to reset things on a computer controlled vehicle.
All that said, faulty/loose/corroded/rusty/high resistance, ground connections are a common woe on computer controlled vehicles.

Intermittent problems are sometimes difficult to trouble shoot.
SO, a wiring cable & computer electrical connector wiggle test may be a worthwhile thing to consider doing.

As our electrical systems only have 12 volts or so to work with, it doesn't take much resistance in a circuit to cause mischief. So, All battery to engine & body grounds need to be clean, bright & tight. This would include the crimped, or molded on wire terminals, or broken wire strands in a run & the B+ connection between the battery, alternator & under hood power distribution box.

The next electrical woe for consideration would be low circuit voltage from a weak battery with sulfated cells, or an alternator with leaky or shorted diodes, not able to keep up with electrical system demand & causing the sensors to give the computer corrupt info, or the computer to corrupt the info it's getting.

Maybe also consider performing some under load voltage drop testing with your multi-meter, as outlined in the Battery tutorial sticky, or maybe perform a under load wiring wiggle test to see if you can induce problems.

Or, maybe consider running this puppy by your favorite auto parts store & ask their test guru for a no cost, under load electrical system check-up with their electrical system tester. Expertly used, it can often spot alternator, battery, wiring, or connection problems.

More thoughts for consideration, let us know what you find.