Check Engine Light On and Off

[SiennaLover69]

So this has been going on for months. Ill have the check engine like come on for a few seconds then it will turn off. I think the first time I noticed this was about a 9 months ago it popped on once while driving at night. I was unable to check it out because the alternator went out a while after it and I had it in my garage for like 4 months before I got it fixed.
Anyway back to the topic, I got my galant up and running back in February and it was running fine for a while until I got the check engine light. Like I said before it pops up at random I can get it popping up a few times during one day, then it can be 2 weeks or 2 days before it pops up again.
When it does pop up, it can go on for a few seconds and then turn off and then pop back on for a few seconds again and then disappear. It pretty much is very incosistent when it pops up lol but it never goes on and stays on. It pops on as I start the engine but I forget if thats normal or not lol.

Ive got two pda's to use as dataloggers but the palm llc that I have is dead and I dont have the charger or data cable for it. The other palm that I have is a palmvx that I have been unable to actual get to connect to my laptop to get mmcd on it. So if anyway has had the issue also and my give me some pointers it would be much appreciated as ive checked online, tons of threads and to no avail.

Also, I tried pulling the check engine codes using a multimeter, im not sure if I did it right but here's what I got. So I either got that it is the knock sensor or the fuel injector sensor (I got that checking the pulses and comparing to the list from dsmtuners 1g code reader thread).
The only thing I notice different about my galant is that it idles a little funny on startup. it'll go up and down from 2000 rpm to 3000 rpm for a minute then chill at 2000rpm.

 

[SiennaLover69]

Actually I was wrong about something, I just turned on my car and it when from 1000 rpm up and down to 2000 rpm, resting at 1000rpm.
I still didnt hear anything, no knocking or anything as far as I could hear. I had my 4 year old nephew bouncing around the inside so im not 100% percent sure lol, but im assuming that knockin in the engine is loud? Ive never really heard any engine knocking before lol.

I tried using the multimeter again to check the code but it was bouncing around a lot, but was still more consistent around 3 or 4 long pulses to 1 short pulse. But once again im not fully sure if im doing that right lol, because then after the short pulse its one long and a short pulse again then drops to zero, a few random pulses then 3 or 4 long pulses then 1 short.

 

[mitsuturbo]

1000 is a bit of high idle for a car with stock ecu. It sounds like the BISS is out a bit and/or the ISC isn't working all that well if it's surging when you start it up.

A knock sensor could very well cause an intermittent CEL. I had one do that some number of years ago. Check the wiring on it first. Make sure it's not been spliced or hacked up in some fashion.

FYI, the knock sensor detects detonation, not rod knock. You'd hear rod knock, and yes it is quite loud. Detonation is difficult to hear unless you have stock exhaust, and that almost sounds like aluminum foil is crinkling in your engine bay.

Get a better reading on the code, and you'll probably find out the knock sensor circuit has a problem. TPS is also known to cause intermittent CEL quite often.

 

[SouthCaliVR4]

Where do you live? I'm north san diego county.

 

[SiennaLover69]

1000 is high, what should the idle be for a car with stock ecu? I think its always been at least slightly below 1000 if I remember correctly.
Alright, at least ive got something to check on, im still not too great with cars yet, so ill see what I can do before consulting with a few people I know lol.
Im almost certain ive got stock exhaust, my car is almost all stock. But I dont think I heard anything that sounds like aluminum foil crinkling but Ill check again to be safe.
But ill check the reading again, ill try to get this crappy palmvx working, I guess its an issue with Win7. But ill try it out and check it. Dumb question btw, regardless of method whether I used a datalogger or the multimeter, will I always be able to get a check engine code, even if the check engine light isnt on? But I will see what I can do and get back to you guys with more info sometime this weekend. Thanks for the quick responses btw!

And I wish I was in North San Diego area, im always in Carlsbad and Oceanside though because of family lol. It is awesome there. Unfortunately though im in the Sacramento Area. Not that theres anything wrong with Sac its just that San Diego is better lol.