I have a 1999 Mitsubishi Galant with a 2.4L Engine. The engine began acting up a little at a time untill i was unable to restart the motor at all. It acts like it's trying but will run, it just spits and sputters a few times and dies. I checked the spark and found out it was firing twice as many times as it should. On the number 1 cyclinder it would fire at TDC and Again at the Exhaust stroke. I checked another cyclinder same thing with it's spark plug too. I replaced both coils, no difference. I'm suspecting the Crank position censor but it must be sending the signal. Could it be the ECM Engine Control Modual?
2007-02-22 10:36:15 · 6 answers · asked by dlk426 3 in Cars & Transportation ➔ Maintenance & Repairs
I take it your car doesn't have a distributor. What you've observed is normal, it's called a lost or wasted spark ignition system. You have multiple ignition coils, each coil supplies a pair of cylinders. To reduce the complexity of the control logic as well as the number of coils required, both cylinders of the pair are sparked simultaneously. Since the cylinders are 360 degrees out of phase, one is on compression and the other is on exhaust. The spark on the exhaust stroke does no harm, it's simply "wasted". As long ast the ignition spark is timed correctly, everything is fine.
Whatever your problem is, it sounds like your ignition is working correctly.
2007-02-22 10:46:03 · answer #1 · answered by anywherebuttexas 6 · 1⤊ 0⤋
The galant does not have a cam sensor, therefore the ecm doesn't know if it's getting the fire signal for cyl. 1 or 4.
( f.o.1-3-4-2) It fires 1 and 4 at the same time through a combined coil pack. This also helps reduce emissions as well, letting excess fuel burn on its way to the cat. Your problem lies elsewhere. Possibilities include fuel pump/delivery, timing belt, bad plugs, map or mass air flow sensor. Run a computer diagnostic on it as a starting point.
2007-02-22 10:47:51 · answer #2 · answered by shopteacher 4 · 1⤊ 0⤋
I am not sure what ignition system your car uses, but if its a Distributorless ignition, its normal. GM has used that system since the late 80's. It sounds strange, but I took a class from General Motors years ago. For example, if you have a DIS car with 3 coils, 2 towers on each coil, when each coil fires, it fires both. The exhaust is the "waste " burn spark. ( since the fuel has exited the cylinder, it does nothing but spark a "dry" cylinder) Its way to in depth to get into, but yes, its normal. The exact reasons behind why they did it, I'm not an engineer, maybe ask them, but its nothing to be worried about. I would suggest looking beyond that and finding the real reason why the car doesnt start- Good luck
2007-02-22 13:56:19 · answer #3 · answered by mrautomechanic 4 · 0⤊ 0⤋
It certainly could be the ECM, but being the price of that, I would change the crank sensor first. I have had a similar problem with this. Your crank sensor is a simple Proximity switch, it counts things for the ECM, if it is counting wrong, it will not run right.
Best of Luck!
2007-02-22 10:41:12 · answer #4 · answered by Tweendasheetz 3 · 0⤊ 1⤋
My guess would be the ECM. The crank position sensor only sends its signal when the crank passes it. Since that is activated by an imbeddded magnet in the crank, I would say you have an ECM problem.
2007-02-22 10:43:05 · answer #5 · answered by yes_its_me 7 · 0⤊ 1⤋
The only thing I can think of is to reburn any unburned fuel.
But I've never heard of that.
2007-02-22 10:43:18 · answer #6 · answered by Anonymous · 0⤊ 1⤋