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I have a 1992 Isuzu Trooper that I have owned for about 3 years. I love the vehicle and have recently moved to Colorado Springs (6,000 feet elevation) from Boise. Historically the vehicle would start up immediately about 25% of the time, the other 75% of the time I had to keep my key cranked for about 2-3 seconds with the gas pedal to the floor before ignition. It never really bothered me, so I didn’t do anything about it. Now that I am in Colorado the vehicle won’t start 75% of the time, no matter how long I crank. It may occasionally sputter for a second, but then immediately dies. If it is the rare 25% of the time when it starts immediately there are no problems and the vehicle runs just fine. After turning the vehicle off and then immediately trying to restart the engine, it won’t start at all. I have to let it cool and then maybe (25% chance) it will start. Thoughts?  

i think you have had a problem and its getting worse...

i would probably start with the cheep items...  and easy to install.. like the throttle position sensor on the side of the throttle body..

it tells the computer how far you have your foot on the gas pedal...

you should really start with reading the codes on your trooper.. there are several different models covered at autozone.com

start here at autozone.com after you join and log in .  

REPAIR INFO,  1992 ISUZU TRUCK TROOPER 3.2L MFI SOHC 6CYL ,REPAIR GUIDE,  EMISSION CONTROLS,  TROUBLE CODES,   READING CODES,


the code descriptions are listed in the same area...

REPAIR INFO  1992 ISUZU TRUCK TROOPER 3.2L MFI SOHC 6CYL REPAIR GUIDE  EMISSION CONTROLS  TROUBLE CODES   CLEARING CODES


it will point you to a circuit that is giving you a problem...   but.. you do have to understand something..   it points to a circuit.. a sensor..   but that does not mean the sensor is bad..  it could be something at effects that sensor.. or the wiring to it..  on other information sites... they have full factory repair info... sometimes thousands of pages.. depending on the car.. the autozone site is free..  but enough to get you started..

some of the troopers can be tested with a scan tool..  some not..   you will at least need a digital volt meter.. they start at 5 buck..

post what you find...  and if you need more info..


it could also be the ECM...   some of them need to be resoldered inside.. by someone who knows what they are doing with a soldering station..    

there is also possible that you have a bad ignition switch.. or a dirty relay..  

Trouble code 12 is what the Trooper is displaying.  I don't see this trouble code on the autozone website for my vehicle.  I'm not sure what this means.  

code 12 is normally no RPM signal from the distributer...

there are so many things you need to verify ...

my first thought..

throttle position sensor..
coolant temp sensor and its wiring..

power from the ignition switch getting through the main relay to the ecm  and to the fuel pump relay...


the fuel pump....  

In my experience this problem is related to a fuel pump going out or the ignition control module(ICM). To find out if it is fuel related spray some starting fluid into the intake only when it will not start. If it fires up then it is fuel related, if it doesnt then it is more then likely not getting spark. Pull a spark plug and test for spark, if there isnt any spark more then likely your ICM is intermittently failing.  

dtc 12 indicates no reference from the distributor. The ecm uses a hall effect sensor(sometimes called a stator) in the distributor to time spark properly. I have diagnosed and repaired the same problem on another vehicle. First ensure that there are no problems with the wiring connected to your distributor. More then likely though the stator is faulty and needs to be replaced. Hope this helps =)