Knock sensor 1990 3vze engine
06-27-2009, 12:28 PM
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Knock sensor 1990 3vze engine
I recently replaced a bad head gasket on my 1990 toyota Pick up. after doing this the check engine light came on with the knock sensor failure code. I put on a new sensor and wiring harness. The wire going back to the ECU unit checks out good and has no continuity to ground. The shielding wire seems to be working properly as well. The factory manual is somewhat vague about this sensor in certain areas. Each time I turn off the engine that code goes away and does not come back on until you run up the RPMS on the engine. Is this normal for that code. I also do not see any real change in the timing before the code is activated and after it comes along. Is this possibly an ECU failure and if so why did it go bad as soon as I started it up after replacing the head gasket.
06-27-2009, 02:56 PM
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Oddly enough. I have a "similar" issue.
3 years ago,I had my head gaskets go bad and replaced. Everything was fine before going to the shop. The very day I get it back...as soon as I reach 10mph,the check engine light comes on and stays on.
It's never caused a problem,so I just keep on driving. My friend that did the work in his business,feels as if he "missed reconnecting a wire somehwere",but...I can not find and stray wires and have no engine running problems at all.
I have yet to figure this one out,but I sure would like som help figuring it out.
:>)
3 years ago,I had my head gaskets go bad and replaced. Everything was fine before going to the shop. The very day I get it back...as soon as I reach 10mph,the check engine light comes on and stays on.
It's never caused a problem,so I just keep on driving. My friend that did the work in his business,feels as if he "missed reconnecting a wire somehwere",but...I can not find and stray wires and have no engine running problems at all.
I have yet to figure this one out,but I sure would like som help figuring it out.
:>)
06-27-2009, 03:55 PM
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Hi Dutchboy
That's exactly what mine does. You can rev the engine in park as high as you want but as soon as you get to about 10 mph the signal comes on. One other thing that makes me wonder about the ECU is that when it's idling at times the rpm's will go up about 400 for a second or two and then back down. I would just run it with the light on too but in CA. your not going to pass a smog check for your registration renewal.
That's exactly what mine does. You can rev the engine in park as high as you want but as soon as you get to about 10 mph the signal comes on. One other thing that makes me wonder about the ECU is that when it's idling at times the rpm's will go up about 400 for a second or two and then back down. I would just run it with the light on too but in CA. your not going to pass a smog check for your registration renewal.
07-05-2009, 03:09 PM
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Hi Dutchboy
That's exactly what mine does. You can rev the engine in park as high as you want but as soon as you get to about 10 miles per hour the signal comes on. One other thing that makes me wonder about the ECU is that when it's idling at times the rpm's will go up about 400 for a second or two and then back down. I would just run it with the light on too but in CA. your not going to pass a smog check for your registration renewal.
That's exactly what mine does. You can rev the engine in park as high as you want but as soon as you get to about 10 miles per hour the signal comes on. One other thing that makes me wonder about the ECU is that when it's idling at times the rpm's will go up about 400 for a second or two and then back down. I would just run it with the light on too but in CA. your not going to pass a smog check for your registration renewal.
Not sure what your idle jumping issue is
My check engine light coming on after 10mph,has been doing so since my head gaskets were replaced a few years ago. The only reason my emission test passes,is because my friend (that works in a legit shop) is the one that did the head gasket job and he also does my inspections. I keep telling him,the check engine light was coming on,but it wasn't effecting anything. It's been like for a few years now. He tells me "oh,I probably forgot to connect a wire somewhere".
Well,needles to say,he never looked into finding said wire and I can not tell which wire connects to what under the hood. As long as my bud is breating,I own the rig and he's working in mechanic shops...he'll pass it.
As wrong as that might be...I don't need to hear smack from anyone on that. I read all kinds os illegal things that some of the guys on this forum get into...so nya!
:>)
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