: Help! Why Does My Catera Quit Running?



cadillac newbie
03-05-05, 07:37 PM
I have a 1999 Catera with an intermittent stalling problem. The vehicle will run good, then suddenly it shuts down and won't start for several minutes. I have been to the dealer twice this last week, and we can not reproduce the problem there. They checked the computer for codes and said nothing shows up, therefore there is nothing they can do.

I had them replace the Crankshaft Positioning Sensor yesterday, to no avail. Shortly after I brought the vehicle home it would not start- it would just crank and crank. I again had it towed to the dealer, at which time it started right up and the problem could not be duplicated.

Any suggestions?

stevehogan
03-05-05, 08:55 PM
When the car does start, does it run OK? No acceleration problems or idling issues? Since they checked the codes and said nothing showed up, I'm leaning towards some sort of intermittent in the fuel system, such as an intermittent fuel punp, especitlly if it runs OK when it does start. It could also be a problem with the engine coolant temperature sensor (which the ECM uses to make some starting decisions). When the ignition is turned ON, the electronic control module (ECM) compares the engine coolant temperature to an internal clock to determine if a fuel pump prime is required. When the ECM calculates that a fuel prime is necessary, the fuel pump relay will be turned on for 2 seconds. The pump remains ON as long as the engine is cranking or running and the ECM is receiving reference pulses. If there are no reference pulses, the ECM shuts the fuel pump OFF within 2 seconds after the ignition is switched off. If the ECM calculations indicate that the fuel system still has adequate residual pressure, a prime will not occur. Thius, if the coolant temperature sensor says the car is warm, but it is indeed cold, the pump won't prime and the car will be a hard- or no-start. So I guess a good question is, does this problem occur when the car is still warm or is it a cold-start problem?

cadillac newbie
03-05-05, 11:55 PM
When the car starts it does run good - it has a smooth idle and good acceleration. The engine generally dies shortly after it has reached operating temperature (suddenly as if someone turned the key off). Usually it will restart after sitting for ~2 minutes. Yesterday was the first time it would not restart until it sat overnight, then it started up first thing.

Can the fuel pump cause this problem, or would it give an error code?

What about the ignition key - I believe there is an antitheft chip built into it - do these go bad, if so should that produce an error code?

stevehogan
03-06-05, 10:36 AM
Because the engine dies after it has been started, it's not the antitheft key. Once the car is running, the antitheft circuit has no effect.

The fuel pump COULD be the problem. I believe that the fuel pump and the fuel pump relay can both be intermittent without setting any codes. I would have suggested the CPS, but you already had that replaced. (A bad CPS will tell the ECM to shut down the fuel pump.) Look and see if the fuel pump relay is properly seated in its connector (it's in the ECM housing at the front of the engone compartment). It's POSSIBLE that the relay itself is intermittent. Otherwise, you should go through the fuel pump diagnostics, which includes testing the pump pressure before you replace the pump. Intermittents are a pain to solve. You could hook up a test lamp to the output of the FP relay and run a wire temporarily into the car. Then when it dies, you will see if the FP has power. Ditto for a pressure gauge - see if the FP has power but is not producing pressure. Fuel pumps can be finicky.

Next guess is the ECM, but that's a pain to replace (and expensive). Another thought - it's probably not the ignition coil or related stuff as the car completely dies and there are no codes set.

One last thought - and I should have been bright enought to think of this first :bonkers: - before you do anything else, make sure the Fuel Pump Fuse is not loose in the fuse holder.

Good luck :banghead:

mudshark
04-02-05, 09:02 PM
My 1998 is in the same position. It sometimes chooses to crank and not start. Usually after about 15 minutes, it will kick. Lately though, it has been quitting on me and then I have to wait until it will start again. It's at the mechanics now and he's checking (it started and then finally gave out on him). I'll keep you posted

dwheeler
04-04-05, 02:09 AM
I had a fuel pump go bad. No hints before it happened. It just wouldn't crank up one morning. Everything seemed fine, it just wouldn't run. It fits the model of not having problem codes.

Chaztera
04-05-05, 11:54 PM
Well this sounds exactly like what I had happened to me...
Mine did this for about a week till I took it into the shop. Cost
about $157.00 for the part & $65.00 for the install. It was the Crank location detection sensor. It runs great now no more shut downs.

Just make sure you have them computer scan & check all the DTC codes to make sure there are no other problems. The good people in this forum helped me figure out what was wrong. The mechanic couldn't fig. out how I knew what it needed...

Best of luck!

mudshark
04-06-05, 01:38 PM
04052005

:) On day three with the crank sensor replaced and it's back to being the champ that it once was. Thanks again to everyone in the forum as I was saved a lot of grief and especially the tow to a "specialist" that wanted to pop me for $700 for a fuel pump. :lies:
To the other guy who did replace the crank sensor. This can also occur within the cam sensor which doesn't show on diags. Also, check the relay (#20) and the fuse (#18)...could be a grounding problem as my guy found that on the relay. Or it could be something really stupid like a clog in the fuel filter that cuts off the flow.