It's done this since I've owned the car.
It's an omex 600, seems to make most noise on part or coming off throttle, there are other relays under the dash near the ecu but getting your
head down there while driving is a bit awkward !
Do they make noise ? Or is this more likely a relay.
Everything works fine it's just an annoying noise.
Can't say I've ever heard mine buzzing
solid state device so nothing to 'buzz' unless the case is loose.
quote:
Originally posted by jeffw
solid state device so nothing to 'buzz' unless the case is loose.
It shouldn't buzz
Sounds more like a relay?
Thanks
I didn't know if these ecu's had relays in them, must be a relay then, only does it while on the move so I can't Rev and look on the
driveway.
Wonder what relay would likely do that, part or lifting off throttle makes a " Bzzzzzerrrtt" noise, lol, lasts a few seconds or until I give
it more gas.
I Bought a stethoscope off amazon, Wasn't expensive and has paid for itself several times over
Even diagnosed an over tightened drive belt on a dry sump pump
Might be worth looking into?
quote:
Originally posted by perksy
I Bought a stethoscope off amazon, Wasn't expensive and has paid for itself several times over
Even diagnosed an over tightened drive belt on a dry sump pump
Might be worth looking into?
quote:
Originally posted by perksy
I Bought a stethoscope off amazon, Wasn't expensive and has paid for itself several times over
Might be worth looking into?
that is funny.
Thought I would update this thread.
Ive got the dash out to get at the relays and have a proper look and listen.
The engine is a 20v 4AGE silver top with OMEX 600 ecu. BTW
The buzzing is the valve timing relay, which ive swapped and the replacement did exactly the same thing, grrrr.
What i have learned so far is that the valve timing on this silver top engine is RPM activated, the ecu turns on the relay at around 3000 rpm which in
turn powers a VVT solonoid which controls the timing, and then off again around 6000 rpm.
Now what ive noticed is this.
If i rev the engine firmly and quickly blipping the throttle you can hear the relay clicking in and out.
If i rev the engine to the point that the relay would click and hold the revs steady the relay buzzes. If then you press throttle further it stops
buzzing, you can hear it positively click, its like the relay is not quite getting the signal and can't decide what to do.
Seems to me that throttle position is the factor that causes the buzzing not necessarily engine rpm.
But according to what ive read the silvertop engine didn't have throttle position input to control valve timing.
Hope i've described this in a way thats understandable.
Thanks.
ps the engine runs fine, its just a very annoying noise...
Is it a case that the vvt requires a pwm signal to operate correctly, the output from the omex 600 is only low amperage, so it has a relay to up the
output and that is what you can hear buzzing?
It would be possible to replace this with a correctly rated transistor to get rid if the noise.
Dave
[Edited on 24/7/18 by obfripper]
quote:
Originally posted by obfripper
Is it a case that the vvt requires a pwm signal to operate correctly, the output from the omex 600 is only low amperage, so it has a relay to up the output and that is what you can hear buzzing?
It would be possible to replace this with a correctly rated transistor to get rid if the noise.
Dave
[Edited on 24/7/18 by obfripper]
quote:
Originally posted by martinnitram
If i rev the engine to the point that the relay would click and hold the revs steady the relay buzzes. If then you press throttle further it stops buzzing, you can hear it positively click, its like the relay is not quite getting the signal and can't decide what to do.
I've now looked at the oe setup, it is just a plain on/off switching with no pwm using 2 advance states of 0° and +30°, and is controlled by rpm
and map signal on the oe ecu.
As Peter has suggested, it is likely that the load threshold has been incorrectly set, if the omex is using alpha-n then the only load parameter used
is throttle position and must be close to cruising throttle position. It may be possible to adjust this value to allow cleaner switching which would
prolong the relay's life.
It could still be using pwm on crossing the threshold to damp the transition, this would be in the omex configuration if used.
Dave
Your correct, the throttle position causing the buzz is at cruising speed which makes it all the more irritating!
Would i be right in thinking that the original toyota ECU controlled the VVT on RPM, and that the OMEX ECU takes account of throttle position also?
Im going to get the engine mapped properly at some point in the near future as i have no record of it being done before, so will ring a few mappers
local
Thanks again
Bit more info on this.
Apparently the later silvertop engines did have an input from the TP sensor, im also now more sure this buzzing is happening from throttle position
rather than engine revs.
Now booked in for a mapping and rolling road session so im sure i will soon find out for sure whats going on.
Car now mapped properly and relay buzzing solved with a capacitor across it.
It was only making 120 bhp on the initial test, it's now got a healthy 151 bhp and smoother low speed throttle response.
Different car to drive now, especially without the irritating buzzing.