Stalls intermittently at stops when warm...
 

Have Searched for the many postings on this subject but wondered if someone had a "what is the most common cause" or what to check first" list. My 92 90K mile well maintained LS-L recently wil stall intermittently at stops or when slowing abruptly to stop. Starts just fine when cold and problem seems to occur only with warm engine. Car will restart but needing more starter turns and then idle with a hiccup...given gas she runs just fine. Again intermittent...did it 2-3 times stopping at store and restarting but drove home fine and pulled into car, idled as smooth as ever.

Is my MAF starting to fail?..my first SVX had a MAF problem where it just wouldn't start period one day. No CEL lights are being thrown or stored, BTW. Disconnected MAF and car started but with idle regularly going up/down 100 rpms. All the hoses I can see with shroud off are intact.

So, in summary, stalls coming to stop intermittently with intermittent mildly rough idle at times only with warm engine, No CEL, pulls strong otherwise. Starts on first kick when cold and idles at the usual cold start range. No recent messing with parts/repairs.

I'm thinking MAF but open to those opinions of others before spending the $175 for a rebuilt Cardone piece.

Much Appreciated

Re: Stalls intermittently at stops when warm...
 

Disconnect the MAF and then start car. Try driving it that way and see if it improves the stalling.

Re: Stalls intermittently at stops when warm...
 

Will give it a try...the stalling problem is so darn intermittent. Just drove 16 miles with stops and ran perfectly. This morning it stalled 2-3 times after driving 15 minutes or so. Bought some resin core solder and might try the Resolder DIY if this continues. What does the car do with the MAF disconnected...runs on some ECU stored rpm based default program?

THX

Re: Stalls intermittently at stops when warm...
 

Water temp sensor?
Not sure if it would affect it that way but thought I would throw it out there

Re: Stalls intermittently at stops when warm...
 

Well, I resoldered the MAF areas, both the 4 terminals and the 4 spots under the copper foil. 2 of the circuit board connections...the far last 2..had that brown electrolysis look to them which may explain why the resolder didn't help...took her for a spin and had a stall out when I suddenly decelerated to a stop which seems to provoke the problem more often than a more gradual stop.

Temp sensor under the alternator shows a good resistance curve so don't think that's the problem but thanks for the "check it out" hint. Had seen that mentioned as a cause in other posts.

Get the feeling a new/rebuilt MAF is in my future...the stall out problem is occurring daily but fairly infrequently that I am not in a hurry but I get the feeling that one of these days, if it's the MAF as suspected, that it will crap out in its entirety leaving me stranding like it did in the long gone days of 2000...

Re: Stalls intermittently at stops when warm...
 

Did you have this resolved? What's the cause?

Re: Stalls intermittently at stops when warm...
 

Replaced the MAF with the cheaper Legacy MAF and after the ECU got "used" to the calibration difference, she has been running perfectly ever since.

Re: Stalls intermittently at stops when warm...
 

Hi everyone,

I'm having a similar issue. My car will start and idle normal up until the engine temperature begins to reach operating temps (usually about 3-5 minutes in). Then it dies. It won't restart(will crank and spark, just not idling) until I wait 15 minutes or when the engine cools down.

There is definitely a correlation between stalling/not starting and operating engine temp.

And its not the MAF sensor. I ruled that out when I swapped my friends functioning SVX MAF sensor onto it.

My car is a 92, stock, 59k miles.

Thanks

Re: Stalls intermittently at stops when warm...
 

It's a shot in the dark but I would say it sounds like you have a vacuum leak.

Re: Stalls intermittently at stops when warm...
 

I was having some random stalling out issues, it was definitely temp related (hot days where bad, lots of stalling - rush hour drivers hated me).

After trying a reman MAF, then a brand new factor MAF, I figured out it was the MAF connector. I got a connector off of ebay, note, earlier SVXs have a 4 wire connector, Legacys and later SVXs have a 3 wire - took several tried to get the correct 4 wire one (people showing pics of the 4 wire, but mailing the 3 wire...).

I've not had a single stall since replacing the connector.

If it is the connector, you should be able to figure it out by jiggling it and getting the car to stall.

But I would also check for vacuum leaks, and other electrical (ECU) issues.

Good luck!
Ian.

Re: Stalls intermittently at stops when warm...
 

Hi Update.

Ruled out MAF sensor see previous post.

I disconnected the battery for several hours to reset the ECU. (no previous check engine light). Started the car and it ran and drove great for about 30 minutes. I even turned it off to get gas and it fired back up and drove home. Parked at home for 10 minutes then tried to fire it up and it stalls.

This rules out vacuum leak since it drove normal after an ECU reset for 30+ minutes of driving.

More facts! When I was driving after the ECU rest, I did several full throttle accelerations with no issue. Only after about 25 minutes of driving did I sense bucking and hesitation as I "rolled" into the throttle.

Maybe its the Throttle Position Sensor after it gets heat soaked?!

Thanks

Re: Stalls intermittently at stops when warm...
 

@irox what part of CA are you from?

Re: Stalls intermittently at stops when warm...
 

I'm in Pacifica / San Francisco. Not too far from Sacramento. :)

Re: Stalls intermittently at stops when warm...
 

I doubt it's the TPS. It's actually a rather simple device which should not behave as you describe. The bucking and hesitation makes me think one or more coils may be to blame. From my experience they are definitely affected by heat and exhibit those traits under light acceleration under load at low RPM.

Re: Stalls intermittently at stops when warm...
 

hey Blacky,

Thanks for the tip. Ignition Coils could be a possibility since I thoroughly washed the engine bay with water. However, Even after washing the engine bay, the car drove fine for the following 2 weeks. Only suddenly it started having issues.

Nonetheless, how can i diagnose if and which coil it possibly at fault?