I have an older Olds 88 that I bought off of my Grandparents when they stopped driving. It has been a good car until recently. The car started to get a little weak when accelerating and then got to the point where I knew that one of the cylinders was misfiring or not firing at all. The engine would shake and I had a serious lack of power. Then after driving it home one day it just quit on me when I was trying to figure out the root of my problem. So my dad and I took out the spark plugs to find that they were probably the originals from when they bought the car. We looked at one of them and it was evident that it was not firing anymore, so we replaced the plugs and wire and the car ran way better. Taking it out on the road we found that it was running well and didn’t have any of the old problems so when we turned off the interstate to go home, it just died on us and I had to tow it home. We are not sure why it died, but the “Hot” light was on, even though the coolant temps were in the normal operating temps. We took it home and it still would not start. I just looked at the coils and they all seem “visually” clean of any corrosion. I put them back and it started up no prob. I have not taken it out for a test drive yet, cause i don’t want to risk towing it home again. Do you have any ideas of what I should be looking at next to get the car working well again?
I think the first thing to do is get out the car’s maintenance schedule and bring all the routine maintenance shown on that schedule up to date. If you bypass this step, and just try to fix why it wouldn’t start or why the “hot” light came on, you are likely looking at a very frustrating experience. You’ll serve yourself best by doing first things first.
A possibility could be a faulty crankshaft or camshaft position sensor. I’ve only learned of this scenario here, but when the car gets hot, one of these sensors can fail due to heat, which shuts off the engine. Then, after the engine is cold, it magically runs without issue, until it gets hot again and fails. Rock auto online has each sensor for about 19 bucks each. If it were my personal car I’d change them both out, idle the car and let it get up to operating temp and see if it shuts off. That would be my guess. Other then that it could be another type of sensor. Sounds like a faulty electrical thing that is failing when it gets too hot. The highway kept it cool enough.
Replace the fuel filter, have the fuel pressure tested…
I agree with the above but if its the 3800, if the cam sensor goes while running, it will continue to run until it is shut off. If the crank sensor goes, it will shut the car down. If memory serves me correct anyway. I do believe though I would focus on the coil. Running bad plugs can wreck a coil and it can be intermittant or fail when hot and ok when cool. You can’t tell by looking at it and need to use a meter on it. You should be able to get the whole coil and module combined from a junk yard for about $25. I think I’d try that to rule it out. If not you have a spare coil. It also could be the fuel pump going in and out and that is an expensive fix. You would have to do a fuel pressure test on it though when the car is not running. If no pressure, no pump action but you should be able to hear it run for a few seconds when you turn the key on. I dunno about the hot light. If you have a guage, then maybe just a bad sensor.
Get an inline spark tester so that next time the engine quits you can check for spark. If you don’t have spark suspect bad coil or crank sensor. If you do have spark then you know to check the fuel delivery system.
The crankshaft position sensor and/or module are the likely cause of the problem. If you replace the crank sensor be careful to leave an air gap at the timing ring.