blinking check engine light....only sometimes.
blinking check engine light....only sometimes. As the title says but it seems to be under light load at around 2000rpm or so. It started shortly after I put a tank of gas in( within 30km when the tank had 1/4 tank in it). I did find the egr valve was bad and thought that would fix it but it didn't seem to. The light seems to go out or not randomly blink if I drive it with a bit higher rpm or not under a load or WOT. I do notice a bit of a miss at WOT feels like its missing power a bit from what it always seemed to have had. This thing is not recording a code but from my understanding a blinking engine light is a misfire. I put a new ICM in that I'm sure wasn't needed. This winter I did a complete MSD ignition from opti to box to wires and its ran great for the past 2 months. It also only seems to do it when its warmed up a bit like after 5 min or driving and not at idle. Could a bad tank of gas cause this random blinking light and miss?
Blinking light is indeed a dead cylinder/multiple misfires within a given time. I'd start with the simple things like your plug wires. I am assuming this is an OBDII car? I don't think this feature was available on OBDI on account OBDI cars do not have a crank sensor. Either buy yourself a scan tool or go to an auto parts store to get the PCM scanned. It should tell you what cylinder(s) is having an issue.
This is driving me nuts! I checked the wires and them seem like they are connected and fine. I've got a jet tuner so i went and looked at the diagnostic stuff on the car. I saw that someone in the past looks to have turned off the mil light stuff in the car as well as a few other things. The car is basicly stock and has run fine for quite awhile. This blinking light drives me crazy. I hate to blame an opti but is it possible my new Msd opti is causing a misfire problem only under load? The car starts up easily and this misfire seems to come and go when this light blinks with no codes stored only when a light load is put on the engine..
I ran it down to half then put 94 octane in there. still is doing it. I checked all the plug wires in the dark and they aren't grounding out and sparking. The idle sounds a bit off when I listened closer and the miss seems to be everywhere in the rpm range. The light only flashes under load then goes out when the road levels or goes down hill. 6th gear is completely un un useable I'm going like 90mph. I'm really thinking this is a opti going bad or a vacuum leak.
I took the basicly new MSD opti off and the car and rotor look perfect. The bearing however seems to have alot of play in it compared to the oem opti I took off that worked perfect. I'm going to put the oem one back in. I only changed them because i did the EWP thing and while I was in there I thought I'd upgrade it. That may have been a mistake.
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just a quick update. I swapped back to my oem opti and the car runs perfect now. The msd opti I believe had a bearing failure which was messing the sensor inside and causing misfires. I wonder if MSD has warranty on these? this one was made in 2022 but only just ran the past two months. sat in a box the rest of the time.
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Joined: Jun 2013
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From: Kernersville, NC