One of the weirdest issues you will ever read
One of the weirdest issues you will ever read
Ok, to start off, I was not drunk or 'high' when this happened to me. About 3 weeks ago I was at a red light when a big rigg (semi truck) passed me, going opposite direction. He was exactly by the drivers side door, he stepped on it, my car shook and shut off
. At the moment I didnt know what to do, I thought one of the ground wires was lose or maybe somethings wrong with the ecu, so I restarted the car and drove home, I checked a few things under the hood (nothing was out of the ordinary). 2 days ago me and a friend with a sti went for a drive, again Im sitting at a red light and a chopper flew by (that thing was loud), I noticed my rpms drop to about 500rpm, same thing, shook and shut off. I know what youre thinking, this guy is on some different sh*t...
Well yesterday I got my evoscan cable and software so I figured Id play around with it, out of no where I got this idea to check the knock count with something loud outside the car. My next door neighbor has a harley davidson, I figured Id call him over and park the bike facing the exhaust against my evo. I opened my hood and he was in front of the car revving on it. I was watching the knock count and it was ridiculous, jumped to 70, the car dropped to about 600rpm but it did not die. So my guess is, the knock sensor is really sensitive or my particular evo is scared of loud vehicles.
I will make a video in a couple of days when the weather gets better here in Iowa
. At the moment I didnt know what to do, I thought one of the ground wires was lose or maybe somethings wrong with the ecu, so I restarted the car and drove home, I checked a few things under the hood (nothing was out of the ordinary). 2 days ago me and a friend with a sti went for a drive, again Im sitting at a red light and a chopper flew by (that thing was loud), I noticed my rpms drop to about 500rpm, same thing, shook and shut off. I know what youre thinking, this guy is on some different sh*t...Well yesterday I got my evoscan cable and software so I figured Id play around with it, out of no where I got this idea to check the knock count with something loud outside the car. My next door neighbor has a harley davidson, I figured Id call him over and park the bike facing the exhaust against my evo. I opened my hood and he was in front of the car revving on it. I was watching the knock count and it was ridiculous, jumped to 70, the car dropped to about 600rpm but it did not die. So my guess is, the knock sensor is really sensitive or my particular evo is scared of loud vehicles.
I will make a video in a couple of days when the weather gets better here in Iowa
Last edited by Czarcasm; Mar 16, 2013 at 12:49 AM.
Haha yea it's really weird but since the knock sensor reads certain sound waves it made sense but at first It took me about a month to figure out why my car would randomly die the noticed it only happens when big semis and Harley's went by
It's not the knock that is registering, it's your maf. At idle your engine is quiet enough for the maf to "hear" the exhaust of the truck, Harley or whatever else might be loud enough to cause skewed readings. The ecu interprets the additional noise as more air coming in, adds fuel, car goes rich and it dies.
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It's not the knock that is registering, it's your maf. At idle your engine is quiet enough for the maf to "hear" the exhaust of the truck, Harley or whatever else might be loud enough to cause skewed readings. The ecu interprets the additional noise as more air coming in, adds fuel, car goes rich and it dies.
I did some highly [un]scientific testing with this back in 2005. At the dragstrip, there are obvisouly some seriously loud v8's with side exit exhausts and whatnot. I noticed next to the really loud ones, my car would stumble at the line. I put the stock intake box back on, and the issue went away. Went back to an open filter, and the problem was back.
Was years ago, and nowadays with a tune I never see the issue. I think I'm the one making all the noise these days anyway... But, anyway, I agree, it's your MAF reading getting messed up.
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I believe that. On my last evo after a intake and some bolt-ons and tune I actually could hear my maf make some high frequency noise under certain conditions. I believe thats what I was hearing anyway? Can the maf make noise? It deff sounded like a electronic device admitting the sound and that was my only conclusion on what it was.
It's not the knock that is registering, it's your maf. At idle your engine is quiet enough for the maf to "hear" the exhaust of the truck, Harley or whatever else might be loud enough to cause skewed readings. The ecu interprets the additional noise as more air coming in, adds fuel, car goes rich and it dies.
Our cars are very sensitive haha
-Taylor
It's not the knock that is registering, it's your maf. At idle your engine is quiet enough for the maf to "hear" the exhaust of the truck, Harley or whatever else might be loud enough to cause skewed readings. The ecu interprets the additional noise as more air coming in, adds fuel, car goes rich and it dies.
The fact that Evo's have hyper-sensitive knock sensor's I can agree with.. Worn out bearings on the input shaft of my trans would randomly trip a knock code on my Evo, & it took a long time talking to various shops & tech's to trace down the issue of why my car was randomly throwing a knock code when everything associated with fuel/ignition was spot-on.. After replacing the trans with a rebuilt unit it cured the problem.
I'm leaning more to the fact that Czarcasm's Evo's knock sensor is picking up the vibrations & causing the engine to stall. Also, every one of you seemingly has ignored the fact that he said he used evoscan to sit there & watch the knock count as his neighbor revved his Harley in front of the car to see if the knock sensor was picking up the vibrations. What's up with that? Is he imagining things?
because the maf is readin a wrong airflow count and is causing the car to knock. if it was the knock sensor then switching to speed density wouldnt solve the problem because you still have a knock sensor.