dfa_crunch

to start off i drive a 94 camaro z28 lt1 6speed

sorry for the length ahead of time

So last year around this time my car started to stall every once and a while. I noticed it was only when it was cold(i live in massachusetts). I didnt have the money to get it fixed at that time because of college so i let it slide for a bit. I posted on these forums and basically was told that it was probably my fuel pump. I tryed a few different things to my car, new fuel filter, tune up, small things like that and it still stalled every once and a while. When January hit, the stalling got horrible, i could barely keep the car running. Wether it was idle at a stoplight or doing 80mph on the highway, it would stall about every 5 minutes. With the foot on the pedal there was just no power going to the engine, when the rpms went to 0 it shut off. Sometimes it would come back and keep running before it stalled though. I finally got it checked out by a mechanic and he replaced the air flow meter, intake temp sensor, and oxygen sensor. It was fixed in May and only stalled once about a week later and ran fine until a few weeks ago.

The stalling is back and it is horrible, I was driving home today and it stalled about a minute away from the parking lot and i couldnt keep it running. Every time i started it the rpms would jump up and down then die. finally i got it going and was able to make it home. I also feel like ive lost power in the car too

I remember the mechanic mentioning something about the base temperature setting was changed to like -40 or something like that. He asked if the car had a supercharger in it in the past, and i told him the last owner had a supercharger in it. He said they must have changed it for the car to keep running when it was hot. If that makes any sense.

He cleared the computer codes some im guessing that helped fix the problem. I was thinking that it is doing this again because maybe the settings are back to the way they were? maybe i need to have them cleared again? I still dont know if this makes sense, im dont know much about it.

add: also warming the car up does nothing, it will stall sitting in my driveway

dfa_crunch

im not sure if this has anything to do with it but. one of my coolant fan relays 2 or 3 im not sure, hasnt been working correctly.

not to long ago the relay went bad, i replaced it and since then the fans turn on 2-3 seconds after the car starts, and they dont turn off until you shut the car down.

dfa_crunch

tryed seeing if i could get it running today and it shut off sitting in the driveway warming up after about 5 minutes.

should i scan it or will this not show up?

Sweetred95ta

I'm interested in this -40* temperature setting. What sensor is he getting the -40* reading from? What codes are you getting?

dfa_crunch

so now that holidays are over i got time to work on my car.
about the -40* readings, i couldnt tell you. it was almost over a year ago now. dont remember much about it i just thought i would throw that out there to see if anyone knew of anything like that.

been reading around on the forums, correct me if im wrong but it seems like a bad MAF can cause stalling? the car did run fine for about 6-7 months before the problem showed up again. could it be something wrong with the MAF again(it was replaced last may). i ordered a code reader so i can scan my car. it should be in by the end of the week hopefully. i'll scan it and post results

dfa_crunch

I remember now that when he showed me the old MAF the part that received the plug looked pretty much melted and was causing it to not work. I havent checked it again, i guess i forgot about it. Will check in the morning and post. Could something else cause this, and do you think maybe it could have done it again?

Guest47904

Didn't we just go thru a series of questions relating to fans being on all the time??? And you learned that you need to scan it for codes???

Well?????

dfa_crunch

scanner is on its way

dfa_crunch

finally got the scanner in, i scanned my car and well it didnt work.
i plugged the scanner in and turned the key. Fans came on and my check gauges, skip shift, brake, and low coolant lights came on. They all stayed on and no ses came on. tryed it a few more times and got the same result. am i doing something wrong? other than plugging it in and turning the key?

link to scanner
http://www.amazon.com/Equus-3123-GM-.../dp/B000EVU8C0

popstoy

on my 95 i needed a special connector for my obd 1 system whith obd 2 connecter not sure about yours.erratic rpms usually mean distributer

mercedestech

The "scanner" you have will not work on the 94's. Since you were watching for an ses light, I'm assuming you bought one of the many tool that simply short the two pins in the diag connector together. In most pre 96 cars, this will put the ecm in diag mode, and the ses light will flash the codes by blinking "x" number of times for the first number of the code, followed by "x" number of flashes for the second number..etc..etc.. Our cars have sort of a transitional setup between obd1 and 2 for the diag connector. Ther is no way to have the ecm "flash" codes on our vehicles. You will need an actual scanner (I have a snap on that works great). Shoeting those two pins in our connectors just activates the fuel pump.

As far as your running problem, you haven't given us enough info to work with. IE does it start up normally, but starts it's stalling after it warms up? What outside temps does it stall, what is the coolant temp when it stalls? What is the fuel pressure when it stalls? Does it start to missfire before stalling, or just stop similar to turning the key off? You will get a lot better info if you provide as much info as possible.

dfa_crunch

pretty ****ty because someone from these forums recomended it. anyway

car starts normally. it stalls after about 5-10 minutes, i guess you can say when its warmed up. it stalls driving or idled. fuel pressure remains the same. The car started to stall when it got cold and it seems worse when its colder. i live in massachusetts, so i say it started when it went under 50 degrees. it doesnt missfire. When the car stalls the engine doesnt die right away. The pedal does nothing to the engine, and the engine just runs off the transmission until the rpms go to 0 and the car shuts off. When it starts to stall i can push in the clutch and it will die instantly. it seems as if it is lacking oxygen, which makes perfect sense as to why the car was fixed by replacing the MAF the first time.

Guest47904

That would be me.

Sorry but I have a Snap-on scanner and don't use that one but a mutual friend had one and suggested it. He said it worked fine in his 94. Never thought much about it till you mentioned yours didn't work. Should have paid attention since OBDI's on our cars require a seperate power lead cause the OBDI ALDL doesn't have 12 volts. When I checked back, it turns out his 94 had an engine transplant from a 93. If I had looked under his hood, I would have seen that it didn't have the MAF. Sorry, if you want me to purchase it from you, no problem, I can sell it quickly. Just PM me.

Some times you get the bear and sometimes the bear gets you.

A quick suggestion would be to un hook an O2 to force it into open loop and see what happens once it warms up. The DTC's will remain in memory so a local independent shop can retrieve the codes for you. I'll just quietly go away now.

Sorry again.

dfa_crunch

its all good man . Atleast you gave me the suggestion, a cheap one at that. its going back on ebay so no worries. im kinda in a mix right now, im a college student with no job and not enough money to buy books next week for the start of the semester. i do have back up money though. so it gets me, do i buy the more expensive scanner and try to figure the problem out myself, or do i bring it back to the mechanic and let him deal with it quickly and get my car running again (hopefully) so i can get back and forth to class.

Because the way it stalls is exactly the way it did last year, it just makes me think that it has to be the same problem again. I got that haynes repair manual, and i was looking for checks to see if the MAF is failing again. the book said to just tap it with a screwdriver while the car was running and if its bad the car should stumble or stall. well it didn't so that told me nothing. it also says to check the voltage of the connector. Well i havent been able to do that yet, stepfather took my multimeter to work last week and he wont be able to get it back to me for another 2 weeks. I was looking at the wires anyway, and it looks like the connector had been replaced. About 3 inches down the wires it looks as if someone cut the wire and put it back together, a bad job if i should say. So i was thinking maybe a bad connection there, but there isnt enough wire for me to cut it and re wire it.

mercedestech

Since you say if you push the clutch in it will die immediately with no missfires, you can pretty much rule out the fuel system. There are several things on the LT1 that will make it "shut off" like you are experiencing. The most common seams to be the ignition control module, with the coil coming in a close second. The opti can't be ruled out until you have someone check your fault codes. If the low resolution signal drops out, or is shorted to the high resolution signal..the car will die. Both issues will usually set opti-specific codes for the corresponding missing input to the pcm. Short of throwing parts at your car until it is fixed (not recommended, especially given your tight budget), there is not much you can do without checking the fault codes. I would try and find a ruptable shop to atleast pull codes for you. Keep in mind anything you have done with the key on (unplug the maf etc..) will have set a code. By the way, the MAF will not cause it to just shut off. It can cause a bunch of driveability issues, but the car can run without the maf signal. the pcm will revert to a speed density setup which does a lot of calculations to "guess" what the airflow actaully is. One of the better tests to check the maf if suspected of causing a driveability complaint is to simply unplug it and drive the car. If it runs better with it unplugged, your on the right track (air leaks etc would still have to be considered). But like I said, you would not experience complete shut down from a failed maf. hope I'm helping..