Questions and Answers

Isuzu Trooper II Mess Of Problems Q. I have this 1988 Isuzu Trooper II, 2WD, 2.6 liter SOHC, 5-speed transmission A/C, 157,000, miles. Says it has cruise control but don't see those parts there. Just got this pile, and cannot get the thing to idle. When its cold it just will not hold an idle, will run for a few seconds, maybe up to 10, then it shuts off and you have to restart.

When it's hot it will idle okay unless the A/C is on. I tried another brain I got from the local junk yard out of a 1989 with what looked like same motor, no change, I have replaced or trimmed up many vacuum hose ends for good connections.

This thing is wacky! It has 12 volts coming into the TPS, the MAP and I would guess the rest of the sensors although I haven't checked the rest. Matter of fact I cannot find the idle control valve at all? Where is this part? Is it under the TPS? Or I cannot find the coolant temperature sensor. Where is this part at also on this model of pile?

I have checked the timing and the timing is very retarded when its cold and you try and start it, you blip the throttle and the timing jumps back to where it's suppose to be. I have tried to set the timing but the adjustment is all the way out and the way the distributor is designed I cannot go any further. I have replaced the fast idle vacuum something or other with a part from the local recycling yard and no luck.

This Trooper also has a flashing code 12, which I have gotten two or three answers on what that means and most don't make any sense.

Now this morning, I unplugged the replacement brain and plugged in the old brain just for pity sake and decided to take it to a so-called friend who runs a car repair business to see what he thought the problem was. He did me no favors just took my money and pushed me on out the door.

However when disconnecting the replacement brain and putting the old brain back in the car did want to idle for a short time which it had never done before then went back to its old crappy self. Does this year of Trooper have a Crankshaft Position Sensor?

The self-help book I have indicates it does but I cannot find it. Someone said they thought it was built in the distributor. Some one else said the heads on these models were usually bad and I am beginning to think none of these people know what they are talking about.

The plugs looked good, and looks like someone has tried a basic tune up with new wires and cap. I could really use some help here, I need to sell this car to pay my rent but won't realize what I would like to get out of the car if no idle.

Your help greatly appreciated,
Mack

A. Mack, you have yourself a fine mess here. But I think I can pinpoint one thing that would account for all these problems. Now, the code 12 is significant. It is "Engine Not Started" and is set when engine speed is less than 200 (two hundred) rpm. This can be related to the Crank Angle Sensor (CAS). A bad CAS will cause all these problems.

I can give you a diagram of the engine pinpointing where the sensors are located, but you're going to need a good service manual to troubleshoot this thing. Go to the local public library and get the Motors Import Service Manual. It will have the procedure for testing the CAS so you can be sure it is bad.

I'm willing to bet 50 cents cold hard cash it is.