Automotive Forums

Greetings,

I have a 1992 Mitsubishi Expo LRV (about 90K miles) that won't start when the temperature is below 40 degrees. When it's 40-50 degrees it sputters and starts sometimes and pretty much always starts when it's above 50 degrees. I just got it back from my mechanic who thinks it's a wiring issue and suggested that I get rid of the car.

What I know (based on information from the mechanic):

-There are no codes being produced when the car runs and when it won't start.

-The check engine light never comes on

-The car has had a tune-up. Plugs, wires, distributor cap, rotor.

-When it doesn't start my mechanic says there is no spark and no fuel injector pulse.

-My mechanic tried a different distributer. He said that every so often it started with the new distributor when it was cold, but there was no reliable behavior.

-My mechanic thinks there is a short somewhere that only manifests itself when it's cold. His only suggestions was to replace the whole wire harness.

- My mechanic says that the fuel pump is working

- I don't believe it's the computer. I have brought the computer inside on very cold days to bring it up to room temperature and it still won't start and I have put the computer in the freezer for a few days and it starts fine if it's above 50 degrees outside when I put it back in.

Any help about how to go about troubleshooting this would be greatly appreciated.

Thanks, Rick  

there are some sensors on most of todays cars  that will stop a car from running,,,originally in there to save your engine.
The oil pressure sensor--- there may be two of them.
The engine temperature sensor--there may be two of them.
 The are hooked thru the ECM and a bad signal will stop the car.  

warm up the engine control module with a hair dryer till it reaches about 70 degrees and see if it starts.  

Hey Rick,

I had the same problem on my 1991 Mitsubishi Mighty Max. When it was cold outside, it would take forever to start. Then it would idle rough until it warmed up, once it was warm it ran perfectly. I replaced the Throttle Position Sensor, I found it at a junkyard for $10. It fixed the problem. Most of the time this will not trip the check engine light and will not trip a fault code. If that does not work here are the things to check in order from cheap to expensive:

 1. Vaccum leak
 2. Fuel filter
 3. Arcing plug wires
 4. O2 sensor
 5. Throttle Position Sensor
 6. Coolant temputure sensor
 7. Mass Air Flow Meter
 8. Cat converter

Alot of people will send you on a wild goose chase, a little time and troubleshooting will save your car/truck from the junkyard.  

I had a 91 Toyota Cressida that did exactly what you describe , it turned out to the cold start injector. If your engine has one I would take a look at it.