Hey guys, at the end of last summer my car died and i tried to fix it before heading up to school. When i started it up it strugled to start but once it finally turned over the rpms would be at 2grand and then slowly dropped back down to 800rpms. The car would run fine from anywhere from 5 seconds to 15 mins (depending on multiple starts) but as time went on the less time it took for the ar to start ating weird. The car starts to shake as the tachometer starts to jump around sparaticaly and the engine backfires untill it stalls out. I could smell gasoline and the spark plugs (brand new) were carbon fouled so the egine was running way to rich. The SES light came on and these were the codes i got:

16- low res failre
36- Hi Res Faiulure
42-EST Grounded

i replaced the optispark,ignition coil,fuelfilter, and checked the wiring. After doing that the car ran fine for 5 mins and still did EXACTLY what i explained above. So i covered the car and was going to wait for spring to come after i returned from college. My signature shows a video of what the car sounds like when it backfires/stalls

I just returned from college and uncovered the camaro. I was told by a few people that its probably the MAF sensor that is causing all these codes and had nothing to do with the opti since i just had it replaced not that long ago before. So I put back on the water pump and checked all the wires and hoses. Refilled the coolant with the remaining coolant i have (which wasnt enough). Started the car after a few tries (without the MAF attached)......the car neve stalled out, even after 25 mins of sitting there. the SES light came on and i got these codes

48- MAF System failure (which was expected)
36- Hi Res Failure
42-EST Ground
43-ESC Failure
15- Coolant Temp too low


i turned off the car and reconnected the MAF. Started the car up and the car wouldnt stall out on me like i thought it would (let it run for 20 mins). it did throw these codes though:

36- Hi Res Failure
15- Low coolant

So while running i disconected the MAF again and this time in only got the codes of:

48- MAF System Failure
36- Hi Res Failure
15-Coolant Temp too low

This puzzled me since there were less codes thrown from before when i had the MAF disconnected and the fact that i couldnt get the car to stall out like i did in the summer when i hadnt changed anything since. Could a bad MAF ause the 36- Hi Res failure to show up??? and i dont understand why the codes changed from what they were in the summer. could this be because of it being spring instead of summer??? ( i am from the Detroit area ). Any help would be nice cause i need this car to be running ASAP.

 

Running the car without the MAF will result in the car being forced to run in open loop mode. From your initial problem description it sounds like it could be a closed loop mode issue from the get go, although I have rarely (potentially never) heard of it tripping the Hi-Res sensor code. If the car runs fine in open loop it could be the MAF, O2's, coolant temp (this is why the amount of time the car would run decreased as you started it multiple times). That said, I still don't think you should be getting a Hi-Res sensor error.

 

so the coolant temp effects how long my car will stay running before it starts to get bogged down and stall out (and throw the orginal codes from summer)?? im assuming this coolant temp code is thrown because i have low amount of coolant in the radiator at this time. I am just so confused on what to do next cause the codes keep changing on me. I really thought it was the MAF but am unsure now and i dont want to go run out and spend 140$ on a part if it isnt even the the reason for this problem. any idea where to go from here??

Thanks

 

The car checks parameters from the coolant temp sensor that determine when it goes into closed loop mode. It actually allows a certain amount of time depending on the initial temperature of the coolant in the car when you first start it etc. Needless to say, the temperature of the coolant does have an effect on how long it takes the car to get to closed loop (providing all the other sensors are operating as they should be), and for you apparently this also determines how long your car will stay running. I would recommend trying to find a MAF for your car from a junk-yard and go from there.

 

porbably a good idea would be is to fill the coolant to the correct level for that the low coolant temp goes away and then re run the same test i did before seeing if the car stays running with the MAF un plugged (in open loop) and then see if i can get the car to stall out while the MAF is connected (in closed loop). Would you agree?

 

I would say you're on the right track. Try your best to test/replace one thing at a time and go from there.

 

Alright, i just got home an hour ago from my cousins graduation and did more tests. I am even more confused then before. I topped off the coolant where it should be by running the car and filling the radiator. I go to start it and it takes 5 crankings at about 6 seconds per crank to get the car started (with MAF connected). The car starts and imediately throughs the codes

36 Hi Res Failure
15 coolant temp too low

it runs for about 5 mins in idle with no problems and when i gave it gas it misses untill you get to higher RPM. So then i disconnected the MAF and let it run for 10 mins and then i started giving it gas and it didnt miss once when reving it. So i connect the the MAF again and give it gas and then it doesnt miss at all. what could cause that to happen? Als the whole time i have my laptop connected to the ECU using Free Scan, and it says it is closed loop. During idle the car temp is about 185degrees and doesnt flex mutch when reving it.

So i turn the car off for 20 seconds or so, reset the codes and start it again, it struggles to start again like before. When it finally turns over the car IMEDIATELY jumps up to 2,500RPM and slowly decreases back down to about 800 rpm. I still get the same codes as listed before and the car does not miss when i give it gas (both when the MAF is and is not connected).

I turn the car off again reset the codes and sit or 30 seconds. I go to start it and it struggles again like before but this time hen it first turns over it starts for about 1 second and white smoke comes out from under the hood and i can smell gasoline. I wait 5 seconds and crank it 2 more times and it turns over and white smokes comes out for about a few seconds but the car remains running this time. It also jumped up to 2500RPM right away again like before. When it got back down to regular idle RPM's (800ish) i gave it gas and it didnt miss when reving it, but this time i got the codes listed below:

36 Hi Res Failure
15 Coolant temp too low
33 MAP sensor signal too high
18 CODE Not Used

Also when i disconnected the MAF the code 48 MAF failure showed up as well (as expected).

Is there a reason for the car struggling to start and starting the way it is?? the only thing i can think of is that the plugs are still carbon fouled from the car running to rich. Also my low coolant sensor is not on so i dont know why i still get code 15. Ughhh this is such a headahe....im so closed to getting this car finaly running again yet im so far away. ANy more advice would be greatly apreciated. Thank

 

The code you're getting for coolant isn't because the coolant level is too low, it's being thrown because of the temperature. That said, you have a pretty vast array of issues it sounds like. The consistent Hi-res failure can only be attributed to the Opti, which could also explain the hard starts and high RPM on startup. It is possible that somewhere along the line your PCM got fried, but that's not something that's easily confirmed. Do you know where the white smoke was coming from? It may just be coolant overflowing since you just filled it, I wouldn't get too concerned.

 

any ideas of why the temperature could be too low? i havent changed anything and put everything back together like it was before. maybe a thermostat issue? also the opti that is in their is brand new so i dont know why i have the hi res failure and the smoke came from the driver side and it smelled like gas so its not the coolant. I always had the susspecision that the it is the computer that is causing the trouble but didnt know how to diagnosis it. Is there any programs i can install on my laptop that i can use to reset/tune the computer???

 

Just because the Opti is brand new doesn't mean that it's working properly, it could have a bad unit. Unlikely if it's an AC Delco or MSD unit, but it could happen. The no name Ebay and Summit Opti's are another story. Last time I checked gas doesn't burn off in white smoke, so I don't really think the smoke smell is correlated with a fuel issue, but I'm not the one looking under the hood. There isn't a program that I know of that you can use to rewrite the whole PCM and more than likely if the PCM is bad it's a faulty component, not a software issue.