ok guys here goes

I have a 1997 deville, 146,000 miles and it just dies at idle, watch the rpm's and they slowly
decrease and then it's as if you turn off the key, engine stall code set,p1599
history codes b0533, annoying fuel gauge bouncy bouncy, b1552 & b1983 power
seat issue duh like i need a computer to tell me that, but anyway it starts back up fine
-- seems to do it more the longer it has been being driven (more than 30min). Can't make it do
it just starting it cold and letting it idle even when warmed to operating temp
changed the iac, still stalling.
I have heard crank position sensors might not set a code on a 1997
deville, so how do I know if it is the crank position sensor or the Ignition
module. @ $300.00 I don't want to change it if that is not the demon. Any
other ideas? The throttle body has been cleaned

Thanks for your help
Bill

i had a problem with my 96 seville stalling with low fuel on hot days and sometimes when the tank was low taking turns the car would lose all power and sometimes stalled if you didnt let up on the gas...suggest fuel pump esp with that mileage

Sounds a lot like a fuel pump. Put a fuel pressure guage on it when it starts acting up and get a pressure reading.

I was told, to check the simplest cause first. Vacuum leak. A tiny one will screw up the injection system. I had a little one. I would start it up. just idle for a bit. Slowly on the gas. It would die. Re-start, then it was fine for another week...... maybe later that day, it might do it again.

Doubt if it is crank sensors. They should set a code if troublesome. The crank sensor story you mention is true of 2000 and later Northstars, not the 97.

What about the idle air control valve that lets air bypass the throttle blade for idle speed control? Is that operating? Sounds like it isn't.

Did you check the fuel pressure regulator? Pull the vacuum line off while idling and see if any fuel is seeping past the diaphragm and into the vacuum nipple of the FPR.

Does it run rough before it stalls? Or does it just cut out? What rpm does it get down to? How is engine performance?(WOT)

:confused: Update time

To answer a few questions and to clarify a few others
Fuel injectors and throttle body cleaned no improvement other tham better mileage

Fuel Pressure replaced, it was getting hard to start in the morning or after sitting for a long period of time.

Replaced some but not every vacuum line on the car, that could always be a possibility

Replaced the IAC

Have not tried leaving a fuel pressure gauge on it yet, guess that and vacuum lines will be my next option.

Car runs like a top, great accelaration at WOT, never hesitates, 25-27 MPG on the highway which is where most of my driving is. Get it hot after 30-45 minutes of highway driving, come to a red light or any idling for more than a minute or two and it will usualy die, notice I said USUALLY, not every time and that is what makes it hard to diagnose. Watch the RPM's and they slowly drop to about 575-600 and then it dies as if you turned off the ignition, No warning signs at all, never runs rough, although once or twice the IAC has caught it and prevented a stall at about 475 RPM's. My wife drove it the other day 2 miles to the Dr's office, never got to operating temp of 195 and she said it stalled on her at a light. No new codes p1441 still a problem which I have had for a few years now, could they be related.

I talked to a mechanic recently and he said even though it starts right back up it could still be the Ignition Module, I have never had a GM module go bad so I don't know how they act. I always thought if a module cut out when hot they would not start back up until it cooled off or reset itself.

Anyone have any experiance with GM module going out?

BTY

Forgot to mention if i keep RPM's about 750 it won't stall

The P1441 could be your problem. Most likely culprit would be the solenoid, I think? I'm not very familiar with the EVAP system. If someone has a manual for a 97, look up that code and post bits from the diagnostic tree.

Finally a code that might help
B1552 - Keep Alive Memory (KAM) Error

Does this mean a bad computer or could it just be a bad connection

Where is the computer and what precautions do I need to take before checking the connections

Oh yeah by the way Talked to 2 different Caddy dealers and they both told me they don't work on Caddy's over 100,000 Miles unless they have always maintained the car. Made real happy let me tell you Might look for a AC DELCO shop next week

What type of computer scanner should they be using

Update

The culprit was a couple of bad plug wires

sometime we overlook the simple things

I am glad you found the two def plug wires.

Did you purchase a complete set for replacement?

Here is a simple tip you can try that will prevent Premature plug wire failure and a host of electrical "gremlins" mysteries.

There are a lot of microprocessors in a modern auto and they love a good ground, are jealous for for grounding.

Your IGN MODULE is as good as the day it was Installed.

The TIP: Carefully remove the IGN MODULE, Unscrew the Coil Packs leave plug wires installed. When you remove the four bolts holding the IGN MODULE metal mounting bracket note that that there is light grey dust on bolt threads CLEAN w alcohol , take a cotton Q TIP swab ,alcohol, and go down into the bolt holes , (manifold, block) Clean out that grey dust.

Remove the ign module from metal mounting brackett. The real working part is obvious the (3 x4" metal covered module). Clean back side and note little short treads . Place generous amount of Dielectric Grease on plate.
Reassemble, Enjoy. COST Zip , Zero Nothing.

Prob is Slight corrosion(bolts) and factory installed DI ELEC grease is gone after 75-100M

Those TWO DEALERSHIPS that would not work on 100K cadillacs should be reported!


regards

:confused: Update time

To answer a few questions and to clarify a few others
Fuel injectors and throttle body cleaned no improvement other tham better mileage

Fuel Pressure replaced, it was getting hard to start in the morning or after sitting for a long period of time.

Replaced some but not every vacuum line on the car, that could always be a possibility

Replaced the IAC

Have not tried leaving a fuel pressure gauge on it yet, guess that and vacuum lines will be my next option.

Car runs like a top, great accelaration at WOT, never hesitates, 25-27 MPG on the highway which is where most of my driving is. Get it hot after 30-45 minutes of highway driving, come to a red light or any idling for more than a minute or two and it will usualy die, notice I said USUALLY, not every time and that is what makes it hard to diagnose. Watch the RPM's and they slowly drop to about 575-600 and then it dies as if you turned off the ignition, No warning signs at all, never runs rough, although once or twice the IAC has caught it and prevented a stall at about 475 RPM's. My wife drove it the other day 2 miles to the Dr's office, never got to operating temp of 195 and she said it stalled on her at a light. No new codes p1441 still a problem which I have had for a few years now, could they be related.

I talked to a mechanic recently and he said even though it starts right back up it could still be the Ignition Module, I have never had a GM module go bad so I don't know how they act. I always thought if a module cut out when hot they would not start back up until it cooled off or reset itself.

Anyone have any experiance with GM module going out?



i am telling you...its your fuel pump with 90% accuracy...everything you described is what happened to me....here try this... when you have below a quarter tank drive on an off ramp and keep your speed up and foot on the gas(within reason) if the car stalls then its the fuel pump...that happened to me all the time till i replace the pump.... i think that it was over heating b/c of the lack of fuel in the tank causing the parts to expand and eventually seizing...but after i straightened out and let up on the gas the car kick right back on

Put a fuel pressure guage on your fuel rail and watch the pressure as it stalls-it will most likely go to zero. The pressure should remain at ~40psi.

i am telling you...its your fuel pump with 90% accuracy...everything you described is what happened to me....here try this... when you have below a quarter tank drive on an off ramp and keep your speed up and foot on the gas(within reason) if the car stalls then its the fuel pump...that happened to me all the time till i replace the pump.... i think that it was over heating b/c of the lack of fuel in the tank causing the parts to expand and eventually seizing...but after i straightened out and let up on the gas the car kick right back on

reading that has made me smile, i once owned a '76 seville (piece of cr*p) and when i went round corners fast the engine would die on me.
turned out to be a faulty pre-pump in the tank. i learnt that to go round certain bends i had to accelerate into them so that i had enough momentum to roll out the other side before the pump kicked back in again.

and i've just had a fuel pump go intermittent on me with a 2001 citroen (OK so it's a citroen, it's french and cr*p but i'm in england and french built station wagons are good value), it just gently dies every now and then.
i took the pump out and sat it in a bucket of fuel and the pump ran for ages with a power supply then suddenly it's speed would drop off a little before kicking back in. i fitted a new pump, about $200 worth and it's now fine.
oh, and this motor is diesel so it's not the plug wires.