Intermittent engine cut-out with no warning when coming to a complete stop. Used to only happen once a week, but became more frequent as time went on. A couple of times had loss of power while driving that reminded me of my old Chevette flooding. Changed fuel & air filters, but problem persists.

Local mechanic pulled up "a few codes" and replaced the Air Charge Temp Sensor and some bad spark plug wires. Could not get problem to duplicate while they were actually looking for it, so they recommended replacing the Ignition Module, Crankshaft Position Sensor, and a few other things (I've forgotten all they wanted, it was back in September) "cuz that's wut the dealer would do." Took the car back at this point, and it ran fine on undemanding trips to & from work for a week. Then the car wouldn't start after a trip to the grocery store leaving us stranded. Went back the next day and it started fine... took it home and left it parked for over a month.

Purchased IM plus coils and CPS on my own and took to a different mechanic to install; but problem persists.

Since most of the problems occur while the engine is getting to idle, I focused my research in the Chilton book in this area. Purchased & replaced Idle Air Control Valve and Throttle Position Sensor... and had to take an hour to teach the engine to idle again. Problem persisted, but not as bad... but got progressively worse throughout December until I was back at square 1.

Maybe I'm barking up the wrong tree, but seems obvious to me that something (some valve, perhaps) is getting hot and sticking in the wrong position at the wrong time... I just have no idea where to go next.
Could the air inlet in the throttle body be closing inappropriately?
Is there supposed to be oil coming back through the air tube connecting the engine to the main air inlet hose between the air cleaner and the throttle body?
The "Anti Lock" light is flashing... glanced at other threads, could this somehow be related?
Should I just drive it off a cliff - assuming it starts at all?

:banghead:

how ya doin redwolf, hey i know how ya feel i am in the same boat with my 93 limina euro with a 3.1L. I have changed the crank positionin sensor, throtle positionin sensor, gutted my cat, and cut the wire to my tcc. still my problem wont go away. does yours stall out when you first start it up and it takes a few times of it stallin before it will stay runnin so you can actually drive it, mine does. my next step is to test my chip in the cpm to see if it is goin bad. did you do anything to the car just before it started actin up or did it just do it. mine didnt start untill i changed the spark plugs and wires. just kinda wierd to me that this is the point it would start actin up, go figure huh. well if i find out any thing with mine i will let you know, it might solve your problem as well.

Howdy, rebel! Have you seen all the review sites that go on about how reliable the Lumina is?
:grinno:

does yours stall out when you first start it up and it takes a few times of it stallin before it will stay runnin so you can actually drive it, mine does.

Not exactly... mine is kinda goofy: if it's been sitting cold for several hours it will start up and take off fine and do really well for a 5 - 10 mile trip. If I shut it down then start it back up again within 20 minutes, it will more than likely get me home - possibly dying at a stop once. If I try to start it up again between 30 - 90 minutes after the first trip, it will either be an increadibly difficult start, or it won't start at all. If it does start, it will run like crap with the Check Engine Soon light on for a few minutes until it figures out what's wrong and fixes itself... then it's time to get home PDQ. If it doesn't start, I have to let it rest and cool off for a few hours - then we restart the cycle all over again.

It's put a real kink in my family's social life.

my next step is to test my chip in the cpm to see if it is goin bad.

That option is still on my list, but I've been putting it off because of the dent a replacement would put in my budget.

did you do anything to the car just before it started actin up or did it just do it. mine didnt start untill i changed the spark plugs and wires. just kinda wierd to me that this is the point it would start actin up, go figure huh.

I replaced my alternator in March (2nd time in 3 years) and the water pump in May or June... this problem started out of the blue in August.

well if i find out any thing with mine i will let you know, it might solve your problem as well.

Any help is always greatly appreciated!
Catch ya later...

test the injectors they can cause problems like that

hey redwolf u might try testin the map sensor as well.

hey redwolf u might try testin the map sensor as well.

Theres a broad range to check to see what can cause the problems.Do you have a scanner?That would be a good place to start diagnostics.It will show the IAC counts,map,egr,injector pulse width,integrator,02,etc,etc.

Also a FP check and test plus an injector(s) test-balance and etc.It does sound like the injectors may be leaking,but then again,a leaking check valve in the pump or bad regulator can be the cause.A leaking egr can cause symptoms as well.

If you dont have a scanner,or a digital voltmeter,vaccum pump,etc or even a FP gauge,youre not at much luck diagnosing the problems at home.Sorry to hear a mechanic could not isolate the problem.
Its gonna be alot of shotgun guessing online.Usually its something simple,but a PITA to track down.

If you dont have a scanner,or a digital voltmeter,vaccum pump,etc or even a FP gauge,youre not at much luck diagnosing the problems at home.Sorry to hear a mechanic could not isolate the problem.
Its gonna be alot of shotgun guessing online.Usually its something simple,but a PITA to track down.

Well, nuts.

The car lost power on the drive home from work this morning, and promptly died when I let my foot off the gas as I pulled over.
It restarted, but idled like crap and the Service Engine Soon light stayed on. There was the tell-tale smell of a bad catalytic converter when it started up, but it shortly went away (this has happened once or twice before).
It got me home, but the CES light only went out briefely a couple of times as the motor dropped into idle.

Check out the wires going from the ICM to the crankshaft position sensor the harness could be cracked leaving wires exposed to be damaged or partially pulled out of the connectors

Okay, the POS will not stay running now. If it starts up, it idles really rough with the SES light on... once I tapped the gas pedal the engine speed dipped down, and when I tapped a little harder it died. Will not restart now.

Flipping through my Chilton book, the section on the PCV valve caught my attention; the symptoms it describes of a faulty valve are very in line with my problems. But where the hell is it??? A picture of a 3.1L F.I. engine in the front of the book points to the valve cover (?) on the front of the engine where a tube connects it to the air hose between the filter and the throttle body... but the section on PCV removal & replacement is slightly confusing (or maybe I'm very tired).
Looking at the spot on the valve cover (?) like in the picture, all I have is a grommet with the air tube stuck in it.

If the PCV went missing sometime last year - and the last time anyone was in the engine compartment was during a water pump change in May-ish - would this be the root cause of all my problems? And if so, would there be collateral damage to various other parts of the engine since I've been driving this way since August?


Check out the wires going from the ICM to the crankshaft position sensor the harness could be cracked leaving wires exposed to be damaged or partially pulled out of the connectors

I've checked as much of the wiring as I can get my hands on and it all seems in pretty fair condition. Honestly, I don't know where either of these parts are... can you point me in the right direction?

ICM(igntion control module) is behind the coils, has three different connectors plugged into it, you have to get under the car to check it out, the one set of wires will go under the oil pan to the other side of the motor-the ones you want to look at.
The pcv valve is usually stuck in a valve cover on the motor, check both valve covers only one usually has a pcv(as long as the motor is a v block) and the tube usually goes to the intake manifold and the other is just a tube and grommet that connects to the air intake, so your pcv may be on the PITA side of the motor

Have you checked the code yet, should be instructions in the Chilton

if you want to know haw to check why the ces light came on all you have to do is take a piece of wire bare at both ends and connect the top left two terminals of your ecm plugin it is located under the dash a little to the right of the steering wheel you will have to have the key in the on position with the engine off it will show a code throught the ces light it will flash once pause and flash twice that is a 12 it will repeat this 3 times and then show another code keep track of the next code and look it up in a haynes manual or on the internet look for gm service codes if you don"t find the code post another message with the code anyone who knows gm cars and trucks well enough can find these codes and let you know what is wrong funny nobody told you about this sooner

if you want to know haw to check why the ces light came on all you have to do is...

Yeah, I spied that page in the Chilton book when I found the info on the PCV valve. Tried it out this morning before starting the car, and here's the results:

15 : Low engine coolant temperature
23 : Low intake air temperature
(it was about 40 this morning)
43 : Knock Sensor Circuit
53 : System Overvolt

I pulled & reinstalled the ECM fuse to reset module and lo-and-behold, the car started... idled like crap for a little bit, but I spent the next 25 minutes doing the re-teach idle routine. Idle is fairly smooth now, but I don't trust it enough to take it out for a test drive.

Re-checked the codes, and all were still present except 23.

1.) Shouldn't engine coolant be up to temp after idleing for 20 minutes?

2.) Would the knock sensor be responding to the engine vibrations caused by the rough idle, or should it just be replaced for the heck of it? I think the book said that the ECM will retard engine speed if this sensor trips, but would it really contribute to all of my problems?

3.) Since there were no MAP Sensor codes, can I assume that vacuum is normal and stable - and thus, there is nothing wrong with the PCV Valve that I still cannot find? (I'm starting to believe it is located on the rear valve cover, but I cant see through the intake manifold plenum)

4.) The System Overvolt code gives me concern because I've replaced the alternator twice in the 3 years I've had this car; I guess something's not right because every now & then I'll get a static shock from touching the body when getting out of the car after shut-down. Is there a separate voltage regulator that I can adjust, or is integral to the alternator? Any other special thing I should look for, other than frayed/chafed wiring?

The static shock probably has more to do with your tires and the clothing you happen to wear. You might want to check your battery connections, corroded or loose will cause strange things. Voltage regulator is internal, I've replaced a few of these alternators myself, a couple on my 96 K1500 and one on a Lumina

You might want to make sure your injector o-rings are in good shape if you have MPFI or TBI. If you are leaking a bit of air around the injector, it could cause your 43 error. :2cents:

system overvolt I really couldn"t tell ya never experienced that problem. vacuum is probably good but if not you should be able to hear a hissing sound from in the engine compartment. to find out why code 23 keeps coming up you might need to hook it up to a scanner you can usually do that for free at autozone most other places charge out the ass for it. If you believe you have a coolant problem change the thermostat if not already done its only 10 bucks and well worth it. Also sometimes a little piece of crap can get stuck in the thermostat and hold it open thus not warming up very fast, takes mine about 20 minute to warm up though. Good luck.

Changed PCV valve & MAP sensor just for giggles... no fix.

Next step will be the mechanic, but I think I'll go car shopping this weekend as well.

Your problem is the ecu is bad..i have run into this problem many times before..the ecu is sensing that the voltage is 25 volts causing the car to flood and sputter..causing a loss of power and stalling...

here is the last post from it...this was the fix for the car
http://www.automotiveforums.com/vbulletin/showthread.php?t=184210

Remove the IAC Valve located by where the air intake hose is located, spray the inside of the chamber and the IAC Valve with carb. cleaner.
When the IAC and chamber gets carboned up the car will not function properly or will not start. Just ran across this problem this last week.

Vaccum leaks, check for vaccum leaks.
Also, pull off the intake plenum (part on top that says 3.1MPFI) and go to town on it with a bottle brush and a can of carb cleaner. Get all the carbon out of it. Clean out the throttle body as well. And when you get done with that, and get it all put back together with new plenum and tb gaskets, get a can of seafoam and run it in through a vacum line. A good one is the one for the cruise control balloon by the battery. Theres a t-fitting there that is good for this. Follow the instructions on the back of the can of Seafoam.
If the plenum is extremely carboned up, you might have an EGR valve stuck open. Those can cause problems like this. Try that and see if it helps.
PCV valve on a 3.1 is on the back valve cover. On the right side if your lookin at it from above. Its got a funny shaped rubber hose that you have to get from a dealer if you break it. You can do that while the plenum is off and it will be easier to get to. :bigthumb:

I have a 93 Lumina v-6 3.1 and the pcv valve is located on the valve cover that is close to the firewall just below the map sensor. Must tilt the engine to gain access. I had to remove the map sensor. The hose runs from the pcv valve to the underside of the intake manifold. When I attempted to change the pcv (the hose being brittle) busted off near where it connects to the underside of the intake, which is impossible to reach. Be gentle!

where is the knock sensor on a 3.1 located , and what does it look like?

I doubt the knock sensor has anything to do with it. If it is coding for that, it probably relates to excessive knock, which can be caused by too much air (lean), poor fuel delivery (lean again) or excessive engine temp. I forget, have you checked fuel pressure, or changed the fuel pressure regulator?