89 - Won't Start, No Check Engine Light

RoyalViking · 07-02-06, 11:09 PM

The engine cranks but will not start. I have the factory manual and started the troubleshooting. I found the check engine line is not on when the engine is off. I had thought the ECM was bad. I didn't want to replace that without checking further. I found a couple things. The the lead coming from the fuse block ECM Eng Fuse (circuit number 439) to the ECM was to have 12 volts. I measured less than 1 volt. I then checked the other points where this circuit terminates. The terminal at the ESM and found the same. The lead at the Cooling Fan Relay was the same (the last time I ran the car I noticed the cooling fan did not turn on). I did check the fuse and it is ok. At the fuse block I have 12 volts on both sides of the fuse.

The manual shows there is a splice somewhere in the harness. Has anyone ran across this before or have any suggestions?

Vettefan87 · 07-03-06, 12:05 AM

Did you short out the two pins on your diagnostic connector then turn the key to the on position to check to see if you had any codes?

RoyalViking · 07-03-06, 09:20 AM

Sorry, I should have included the what the factory manual mentions about the lack of a check engine light when the key is in the run position.

If the key is in run and the engine is off the check engine light should be on. The manual states that the ECM will not work unless there is power to three pins on the ECU, ECU failure, or a bag ground. That is where I started in troubleshooting.

Without the ECU working the codes cannot be checked. I am glad I bought the factory manual. I doubt I would have gotten this far.

RoyalViking · 07-05-06, 12:30 PM

Here's an update on the troubleshooting.

I had gone thru the troubleshooting steps three more times to make sure I didn't miss anything. The fan relay has 12V at the connector. Not sure what the issue with the fan is now that I've found voltage present. The other two points, one at the ECM and the ESM connector are spliced in the harness. I haven't gotten a chance to open the harness yet.

While checking this out I had the ECM plugged in and was able to get the check engine light to turn on. Then I plugged in the ESM and the light went out. I checked for voltage again and there was none. I guess it had been an intermittent problem. Fortunately for me I have not driven the car for on the road for some time other than moving it in and out of the garage. This would also explain why the car was running so bad the last time it ran.

RoyalViking · 04-19-08, 05:06 PM

I thought I would give an update on how this eventually ended up.

I had gotten back to trouble shooting last spring. I had replaced the ECM. It ran ok, not great but not bad. It would not pass emmissions and after leaving the inspection station I noticed that for a brief period it ran like it had in the past. Power was back and the engine was running smooth. Like someone had turned a switch on. I decided that I could drive it to work which is 38 miles from home. It ran ok to work and driving home I noticed the alternator had stopped charging. I can tell you that I made it all 38 miles although I was not sure at times if it was going to make it. I replaced the alternator and charged the battery. It ran ok and for all I could see it was charging the battery. I attempted the drive two more times. The second time I noticed when leaving work that the alternator quit charging at a stop sign where I had to make a down hill left turn rather fast. Again I made it home. I tried it a third time and sure enough at the same intersection it happened again. Now during this time I had begun to have hot start problems where it seemed that the engine was lean as it would stumble but not stay running. I finally had a saturday where I could work on it and I was under the dash moving wires to see if there was a loose connector (suspicious that of the down hill left turn may have been a connection issue). I found that when I pushed on the harness the engine stopped charging and if I moved it again the alternator began to charge. It sat all winter and today I was starting the trouble shooting steps with the factory manual. I was checking fuses and when I pulled the Injector 2 fuse (20A) a piece of the connector fell out. I decided to stop there. I started the engine and then held the fuse in place so it made contact. The engine ran great as long as I could hold the fuse in place.

The next step of my quest is to find that fuse holder connector. Does anyone know where I can find one?