'92 olds inoperative condition


#1

'92 Olds Ciera ‘S’ 4-dr. sedan; 3.3 litre V-6 engine; engine code “N”. Multi-port fuel injection. The situation: engine readily starts. Put defroster on and the cooling fan works, the way it’s supposed to. Turn A.C. on and fan comes on, also the way it’s supposed to. With the cooling fan on, everything operates properly UNTIL— Engine temp. gets up to the first white mark on temp. gauge. Engine quits and won’t re-start until engine temp. gets down to 100 degrees or less. Then engine starts and runs fine until temp. gets up to first white mark. I have replaced with new: fuel pump incl. in-tank mesh and exterior fuel filter; checked all fuses and relays (all are good); new oil pump and oil pressure sending unit; new engine temp. sensors, both the sensor for the dashboard gauge and the other that signals the cooling fan to come on when temp. gets up to approx. 200 degrees; new on-the-cooling fan switch; new e-prom chip in the on-board computer; new exhaust oxygen sensor. Checked out tghe three fusible links at the starter. I have also purchased a combination OBD-1&2 code reader as well as previously purchasing a code scanner. These devices only flash ‘code 12’ which means that there are no stored trouble codes. I also checked the ohms reading on the fuel injectors and replaced one injector that showed a borderline low ohms reading. I also replaced the throttle position sensor, fuel pressure regulator and checked the fuel pressure with an approppriate fuel pressure gauge. Everything checks out just fine. Everything is within specs. The engine starts in about 2 crank revolutions and runs fine at about 1700-1800 rpm until the engine coolant temp. sensor pulls in the signal from the exhaust gas oxygen sensor. It’s driving me crazy! Any suggestions as to how to determine the cause of this challenge? My next move might have to be to tow the car to an auto shop that can hook up a fancy-doodle code scanner/reader to uncover the hidden codes that only an expensive shop can pull out of my on-board computer. Thanks,–Prof. Handy/ Bailey, CO.


#2

[b]The next time the engine stalls, check for spark.

It could be that the Crankshaft Position sensor is dropping out once it gets hot. When this happens, there is no ignition or injector function.

Tester[/b]


#3

Hey thanks, Tester. I never thought of that! I’ll let you know results when I get the time to make this spark check.


#4

Crankshaft sensor like posted, or even more common on these cars, is the ignition module. Both will cause the same symptoms and usually dont give a code. The crank sensor is much cheaper. Try that first.


#5

It may be, the engine temperature (conducted) to certain sensors or other components, isn’t well received by them. Technically, the sensor (or, other) gets hot, and goes bananas. The crankshaft position sensor feeds into the ignition coil assembly. To simulate the engine getting hot, use a hair drier (anyones) and play it on the suspect while you check the resistance. A resistance check, while it’s heating up, might show a sudden change as it’s being heated. The output voltage of the crankshaft position sensor, while the engine is running, is an ac signal (I think). If it does show a sudden change, that could be your (errant) boy.


#6

I agree with the ignition control module as being the problem. I’ve had to change these on a 1984 and 1986 Ceira to correct this same problem.