Intermittently does not start

LES9000

MEMBER
1994 PONTIAC BONNEVILLE
3.8L
V6
2WD
AUTOMATIC
110,000 MILES

This problem is gradually getting more frequent. Sometimes after I turn off the ignition the car will not start from 15 minutes to 1/2 an hour. Recently I was sitting at an idle and the engine stopped without turning off the ignition and would not start for a little over 1/2an hour. I'm pretty sure it has something to do with the fuel system, perhaps a relay that controls the fuel pump. From what I understand it is rather difficult getting codes from the car as it is pre OBD2. But I pretty it must have stored some sort of code when it just shut off at an idle if you could put me in the right direction, I will have the done at a repair shop but would have some insight as to what the problem could be. Thank you for your expert advice in advance. Sincerely, Lesley Decker

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,289 POSTS

Hi,

The issue sounds like a faulty crankshaft position sensor. When they begin to fail, heat has an adverse effect on them. Internally, the heat causes expansion, and the vehicle loses spark. Once it cools down, it works again. So, first, you can check to see if spark is lost when it won't start. Here is a link that shows how it's done:

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

Or, if the vehicle has a tachometer, see if it moves a bit when cranking. If it doesn't, this is my first suspect. Do me a favor. Take a look through this link and let me know if it mirrors what you experience:

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

As far as getting codes is concerned, it is really easy. All you need is a short jumper wire or even a paper clip. Here is a link that explains how it's done:

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

I would check for codes. However, I need you to keep in mind that a crankshaft position sensor doesn't always set one. If the signal is lost, it can be the result of things other than the sensor. For example, if you run out of fuel, the engine will stall, and the signal will stop. But that doesn't mean the sensor is the cause.

Let me know if this helps you, if you have other questions, and if you find codes.

Take care,

Joe