The car (97 Buick Le Sabre with 3800) ran fine and started fine until one day last week it did not turn over. After about 10 minutes it was tried again and this time it did start. It was used regularly with no issues for the next few days. Then one morning it didn’t start (or turn over) and hasn’t really been successfully started since. The battery is good and cable connections too. So my mechanic figured it was probably the starter. Since I had this weekend free, me and my friend Johnny replaced the starter. But it still did not start. We then turned the ignition to run and crossed the solenoid terminals with a metal tool and then the engine turned over and ran for a brief period (around 5 to 10 seconds) but then killed. This procedure was duplicated a few times. So we figure it wasn’t the starter, the battery, or most of the larger cable connections. The tension wheel had failed on it in the recent past so we wonder if when the belt blew out if it had hit and weakened a wire somewhere that has now failed but difficult to locate. We also wonder if the car’s security system maybe failed and it thinks the car has been stollen. This might explain why it won’t start or stay running when ignition is circumvented. Note: the panic button on the key fob works properly. All of the fuses were checked and none were found to be blown out. Any thoughts on what the root cause of this problem might be and how to repair it?
I believe you hit the nail on the head with the security system.
Is the antitheft LED flashing when it won’t start or won’t stay running?
Check for fuel pressure at the rail.
If the PCM sees an unauthorized starting attempt, it will cut fuel pressure.
Try your other key first.
GM has the resistors in the key and if they change resistance the car will not start.
I did try the other key but I it did not work. Though I haven’t tried to start it lately. I was thinking maybe it needed some time to reset and then I would try the other key. Probably a long shot. Beyond that, I think I will be checking into the security system scenario in more detail tomorrow. Thanks for the input!
Have you considered checking the junction terminal to make sure the connections are clean with no corrosion?
This terminal should be located near the battery positive post and all electrical power for the car except for the starter motor windings go through that terminal. The starter solenoid power also goes through that terminal.
Well, I think I will just bring it in after all. I tried to locate the wires I needed to splice in a resistor to, which matches the key, but the steering column wiring looks to be too tricky to get at. Thanks again. I will try to report back what eventually fixes the problem and how much it costs…
Follow-up: So it turns out that it was the security system. Apparently the wires that read the resistance in the ignition key must have gotten worn out and they failed. As a result, the car thought that someone was trying to start it with a different, perhaps illegally copied, key. So it shut down the starter and the fuel supply, I think. I took it to a local repair shop where they installed a resistor down at the base of the steering column by splicing it in at a point where the tires weren’t worn. The resistor had to match the key’s resistance. The mechanic told me that the codes had to be cleared and that the key had to be in the run position for ten minutes before this fix took effect and the car could start. It runs good now. The cost of the unneeded starter was about $110 and the repair at the shop was about $80. Not too bad considering that the dealer quoted me $390 to put in a new ignition cylinder with two new keys.
You found a very good shop to do the work and got a great rate to repair the trouble. The amount you paid isn’t even an hours worth of shop labor time at some places.