been a while since i've messed with codes and things...car actually has been running well.

flashing SES means misfire detected correct?

if the light stops flashing after 20sec or so...and the SES stays off...what's the deal?

i have scanning software, but its not installed on my new laptop (not sure i even can).

is there any hard-code stored after a flashing SES if the light stays off after? can i look it up with the scanner?

car has been running fine lately, been WOT several times here and there with no problems.
went WOT in 2nd gear today and ran it up to about 5K rpms...10 sec later the SES started blinking, then stopped. car never seemed to studder or flinch.
it was abnormally cool this AM...55 compared to normally 75-80. car had been running for 2-3 mins.
wondering if the cool air threw off the A/F enough to cause a misfire.

 

I believe for OBD-II the flashing SES is for misfire detection. But I highly doubt that 55* weather could cause that. I would check your plugs and wires.

 

Codes stay stored as "history" even after the light turns off for dozens of cycles, so I'd try and read it. Read my neighbor's Saturn the other day with Predator after his light has been off for a while and it had a knock sensor code stored twice.

 

i doubt anything with the temp was the trigger either, but you never know with a crappy custom tune on a cammed engine.


i'll see if i can get the scanning software up and running.

i may try a WOT run on my way home from work. see what happens.

could have easily been something with open loop/closed loop since i had just left the house.


only other thing i can think of is something associated with an SES code i threw a month ago on a long trip. for the TPS not reading correctly...but only after being on cruise control for 2 straight hours

 

Why are you getting on it hard when it not warmed up yet??

 

actually it WAS warmed up.

i let it idle for about 2-3 mins, then i drove for a mile, then sat at a light for 2 mins.

it wasn't COLD...but it wasn't HOT either.

and it was a 2nd gear run up to about 5000rpm.


anyway
so the SES flashed at me again on the way home....but i was in traffic and had been going along at 1500rpm for several miles. no WOT or anything.

car didn't stumble, or studder or drive any different. the SES just flashed, then turned off and stayed off.


scanning software is not working on the new computer...still working on that.

THIS MORNING...it didn't do anything. let it warm up the same, even did a short WOT run in 2nd or 3rd gear. NOTHING.

i hate intermitant problems

 

Misfire detection is via the CKP sensor. Its comparing the rotational crank speed irregularities to the known pattern for the STOCK engine. It can be triggered falsely in extreme cases by rough roads or a meaty cam. Or by a faulty CKP sensor.

 

thanks fred.

now what does CKP stand for....just out of curiosity.

i'll see if it happens more

 

Crankshaft position sensor.

 

good call....

the K was throwing me off.

 

UPDATE

we had a cold front come through the other day.

and this morning on the way to work the SES flashed at me again....first time in WEEKS (since i first posted this).

it even flashed 3 separat times....i mean it flashed the 10 or so times it does...then stopped for a minute...then flashed...stopped for a minute..then flashed again.
then nothing.

this is the first time the temp has been cool since this first started happening.

i don't understand.

 

Did you ever get it scanned? Did you investigate the cps sensor?

 

Was it, or had it been raining? High humidity?

 

tried to get it scanned....but my software has not been working on the new computer. need to investigate more..

the car stopped flashing the SES...so i kindda forgot about it.

figured maybe it was bad gas or something.


"Was it, or had it been raining? High humidity?"

it was sprinkling this morning....not sure what the humidity was.

might try cleaning the maf when i get some time.
gotta track down someplace to scan it for free.


as far as the change in humidity goes....i can't figure out why the hell the car would start acting up after 3 yrs on the same mods/tune. unless something is going bad (sensor, maf, etc).

 

Moisture in the air can cause a weak plug wire to act up.