1996 Talon N/A: Shuts off at stops

Hey Guys,

Got a whole new problem with the talon today. The good news is that it starts up and runs fine. Other good news is that I had the alternator and the battery tested today and they both tested perfectly fine, and I replaced the air filter and spark plugs today.

Bad news is that when applying the brakes to slow the car down to a stop, the RPM's slide down to around 500 normally and sometimes as low as 250 or less, thus causing the car to shut off sometimes.

I've replaced the spark plugs (needed to be replaced anyways as the old ones were starting to get corroded), and the air filter (also badly needed to be replaced).

Some ideas I've got through googling are a fuel pump and/or O2 censor. I also saw some people blaming it on the transmission but I couldn't imagine that being the problem in this case.

Anyone? I have a feeling it probably is the fuel pump or O2 censor. Anyone know how hard those things are to replace?

Zac

zac atleast check the tranny fluid. it could be possible the tranny is putting a load on the motor at stops like that, and not disengaging like it should. as far as the o2 sensor. its really simple to change out. and the fuel pump is not. it pretty much involves you dropping the tank out from under the car and pulling it out of the tank. can u hear the pump straining at all? you might wanna look at a fuel filter too. cheap and easy to fix. but these would be symptoms of the car running bad all the time, like it would stutter and jump trying to take off or start in the morning.. it might be possible the idle air screw came loose a few turns. what does it idle at in park?

I don't see any of those problems causing it to die while you brake. It sounds like an electrical problem. How exactly did they test your alternator? The fuel pump can be changed without dropping the gas tank. It's a WHOLE lot easier then that. O2 sensor is also pretty easy...but i don't think either of those would fix your problem.

I'd go over your grounds, make sure none are loose..make sure your battery terminals are tight and aren't hitting the hood anytime. Check the tranny fluid and make sure everything else checks out.

you should get a CEL if your 02 sensor is bad anyway. Id check the trans fluid and grounds. Barry's old eclipse did the same thing, and it was in a fire that caused electrical problems if I remember right. His would die in drive if you werent moving and stuff. See what happens if you pop it in neutral when coasting or coming to a stop. Make sure your idle in park is about 750, to high the torque converter may be causing it to stall, to low and same thing.

Idle in park is between 750 and 1,000 usually. Sometimes when I first start it, idle is right at 1100 but once the engine is warmed up and all it idles right around 750.

The first thing I thought was electrical, because my car had the same problem for a while and it just turned out that the negative end of the battery wasn't making a connection, so sometimes when I hit a bump the car would shut off quickly. The only reason it's harder for me to think it's electrical this time is because this shutoff is just so smooth compared to when it happened to my cavalier. My cavalier would just instantly shut off when I hit a bump. This problem is strange because when I brake, the RPM's just ease down to 500, then sometimes 250 or less. Sometimes it doesn't shut off, and sometimes it does.

Tranny fluid is good. Nice and red and its at the correct level.

Also, autozone checked my alternator through the battery. Started up the car and measured how much power was getting sent to the battery.

I'll take a look at some things tomorrow on my day off.

Zac

check cam sensor and crank sensor, my Blazer was doing that exact same thing.

^ I'll have to look into that Matt. Haven't done so yet, though.

I talked to Trevor today for a minute, but I've got some new information about this that I wasn't aware of (Ashley drives the talon usually, not me). This is only a problem when th engine is cold. Once the engine is warmed up, this problem completely disappears, and the RPM's only go down to about 750 (which I believe is standard) at stops.

Does this change anything for anyone's estimates as to what the problem is? I checked the tranny fluid again today and it's red like it's supposed to be and it is full (possibly a little higher than it should be, though). I did notice that the tranny fluid seemed to be a lot more "watery" than I thought it should be. Thought tranny fluid was thicker than oil, but could be wrong about that.

Anyways, yeah this problem disappears when the engine's warmed up completely.

Zac

it has a hard time starting when its a little cold, too. i have to hold the key down for a long time for it to actually start. idk its probably normal since its older and cold.. but i never really had that problem last winter, just lately.

i think the car is just doomed. :Hangman:

Yeah. It's the stupidest thing ever I think.... we drove the car all day today. This morning when we first started driving it, it was a little rough for about 10 minutes of driving. It was sliding down to 200 rpm's or so when I would stop and come dangerously close to shutting off. Then at one stop I decided to see if I could shift it into neutral to see if that would help anything, but in the process of changing the gear to neutral the car shut off.

That was the last we saw of the problem today. I took Ashley to the doctor, then we went to Sams Club, back home, to the post office, to Ashley's parents house, to Target, to westdale mall, then back home. Only that first 10 minutes did the car give us ANY trouble.

So whatever is wrong with the car, it's not a problem if the car is kept warm. I just need to find out what it is so I can see if it can be fixed cheaply. The car runs fantastic otherwise. The hard-start problem that Ashley is talking about, I believe is tied into this same problem.

Zac

really hard to say. Give it a full tune up and see what happens is all I can suggest. Not any way I can think of to test fuel pump strength, and i dont see it being the problem as its just when the cars cold. Fuel system cleaning, fuel pump, check all vacuume lines as a slight leak may not be much issue when the car is warm and wants to run, but problematic when cold. If it seems to take a long time to get it to fire, theirs a good chance it is your fuel pump. I know chevys old pumps actually kinda wear out vs what ive dealt with where they just die. car will run less than desirable, but theirs no real sign of it being bad. Try running some high octane fuel through it with fuel additives/cleaners. Make sure you change your fuel filter too tho.

so auto shop w/ injector/fuel system cleaner. maybe grab a new pcv valve cuz it cant hurt. Put in some good gas, and the additives and fuel filter. No change, try a pump. you know people so it wont cost you much.