ECM, ICU, and Related Starting Problems

Perhaps the forum moderator should put a sticky on this and related forums regarding the 89-95 Tracker ECM problem.

The 89-95 Trackers were built with ECMs from Mitsubishi, as were many other Japanese imports of the same year range. All have had similar problems, and many, many people have spent tons of money replacing fuel pumps, relays, injectors, etc. because the car won't start. The bottom line is that Mitsubushi used sub-standard components in building their ECMs. After about 40,000 miles these bad components burn out leaving your Tracker DOA. The more reputable ECM rebuilders replace the bad bits with high quality bits and you're back on the road again.

So, if your 89-95 (and perhaps later) Tracker won't start but will run for a moment after spraying starting fluid, or pouring a drop or two of gas, down the throttle body, and you can hear the relays click when you turn the key, your first suspect should be the ECM.

Then search the forum for the addresses of rebuilders and take care of the problem. Don't trust an ECM pulled from a wreck, it might only have a few miles left on it.

Can you tell me where the longer ground wire connects to on a 1990 geo tracker. It wont start, unless you push start it. After I push start it, it starts fine for awile. When it was running I took the positive battery cable off and it ran fine, so i think the altanaters good. It has a new battery to. If you dont think the ground wire is the problem, will you tell me a easy way to locate the ECM or ICU.

The ECU is up behind the driver's side stereo speaker. Removing the speaker makes it easy to get to for removal. Silver box about 5"x5" and 3/4" thick. Probably has the Mitsubishi tri-diamond stamped on the cover. (BTW did you know that the Mitsu tri-diamond is a representation of the Zero fighter's propeller blades? Mitsu built the Zero during WW II.)

The ground cable on my '92 Tracker connects to a bolt on the transmission bell housing, in the most awkward and dirty place there is to reach on the entire vehicle.

Ecm or what??
Preveous threads relate the starting and quitting problem to the ECM and this may be the case. BUT, before you go buy either a rebuilt or heaven forbid a new one from the dealer there are some other ereas that you need to look at first.
If you do not know the history on your vehicle you need to look at some basic and cheaper alternatives first those being:
1. Fuel filter, located under the vehicle, passenger side,just ahead of the fuel tank.
2. Timing Belt, located on the front of the engine, just behind the radiator, not that difficult to change and a basic manual from your parts store should give you the step by step procedure.
3. Coil and igniter, located on the firewall driver side, under the hood...You will need a multimeter for this and some detailed instructions not available in the basic manuel, but is available in the "Dealers Manual" one which I have and bought thru E-Bay I think for 30.00, well worth the price as it is soooo complete on diagnostics and all the mechanical.
4. A word about relays, there are "I think" 4 relays attached to the same bracket as the ECM, located under the dash, drivers side, remove the speaker and you will find the fastners that hold all this in place. NOw the relays work a number of functions, one being the MAin relay, that if faulty will give you all kinds of problems with starting and running. The Fuel Pump relay is here too and the function is to turn on the fuel pump when you turn on the key, it shuts down in 3 seconds if you have not started the engine. Then if the engine starts, the ECM will tell it to turn off and on when fuel is needed at the throttle body, based on the load requirements and other messages the ECM is recieving from other sensors. So imagine if you can a light switch on your wall at home and one of your kids standing at the switch and turning it off and on every fraction of a second and how long do you think it will last??? or for that matter the light. These are electro mechanical devices and can fail.
5. Distrubuter, Not much inside this device but there is a magnetic pick-up that tells the ECM where the roter is and what it did on the last pass. All this is tied into the ECM so it can electronically advance or retard the spark.
6. Other related items: Throttle position sensor, O2 Sensor, EGR Valve. All can contribute to the won't start,,,or won't stay running problem.
7. ECM, everyones cure a;ll for no start engines,,It's true the ECM is a piece of garbage and some not all rebuilders replace the faulty parts and some have had great success with getting their tracker on track,,,WHY, because it was the ECM,,,but not always is it the ECM. Do your MAitenance first before you but some very expensive parts.
How do I know all this....because I've bin there done that and it is not the ECM, I know this because I have installed 3 of them to no availle

I agree with iamatracker's post. Basic maintenance and trouble shooting are a must. I will add one more caveat to his post: Test before buying. Follow the testing procedures for each suspected part and don't replace it if it is good, save some money where you can.

See my recent post on will not start again and have a look at the distributor, interesting results here.

i have a tracker part that is located on the front part of the engine. there is a blue one and a red one mounted next to each other. there is also a relay inside of the car that is clicking along with this red part that looks like a vacuum part for gas but has wires attached. the car will click over but not fire can you tell me what this red part is or is there some thing else wrong? thanks

My 1996 Geo Tracker is also not starting at all. We have replaced the TPS, checked the distributor and other items. help!