VTEC Troubleshooting
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From: Tucson, AZ
VTEC Troubleshooting
Ok, I have noticed ALOT of people recently asking about why their vtec isn't working. I'm just going to do some of the basic steps in checking to see why the **** vtec isn't working 
.
1) Oil level, its gotta be FULL. I'm talking at the upper mark on the dipstick.
2) Solenoid, Ok this is a 2 parter. A) take a wire (any wire) disconnect the grey plug on the vtec solenoid and touch the wire to the pos. battery terminal and the solenoid side of the grey 1 pin connector. there should be an audible click from the solenoid. B) If A checks out, remove the solenoid and clean the filter screen. (self explanatory)
3) Speed, the car must be going over 10 mph so the spedo must be working. that means the VSS has to be working. vtec is temperamental isn't it?
4) more oil, check the oil pan. if its dented POUND IT OUT!. this is why mine wasn't working. the pan was dented in far enough to hit the oil pickup for the pump to cause low pressure situation in the head, no pressure no vtec.
5) ECU Swap out to another ECU that you KNOW vtec works on.
6) Car must be at I belive its 80 degrees or higher so let car get to a normal operating temprature.
7) If none of the above work, you might want to pull the solenoid off the head, remove the solenoid filter and verify the piston moves freely.
Thats a basic troubleshoot for it. if i missed anything or got anything wrong just reply and ill change the info.
If you go through all this and it still doesn't work its oil pressure (the pump) or wiring related. so check all the wires for vtec.
Thats it i hope it helps some people.
Joe
[Modified by KAMiN, 5:45 PM 6/5/2002]
. 1) Oil level, its gotta be FULL. I'm talking at the upper mark on the dipstick.
2) Solenoid, Ok this is a 2 parter. A) take a wire (any wire) disconnect the grey plug on the vtec solenoid and touch the wire to the pos. battery terminal and the solenoid side of the grey 1 pin connector. there should be an audible click from the solenoid. B) If A checks out, remove the solenoid and clean the filter screen. (self explanatory)
3) Speed, the car must be going over 10 mph so the spedo must be working. that means the VSS has to be working. vtec is temperamental isn't it?
4) more oil, check the oil pan. if its dented POUND IT OUT!. this is why mine wasn't working. the pan was dented in far enough to hit the oil pickup for the pump to cause low pressure situation in the head, no pressure no vtec.
5) ECU Swap out to another ECU that you KNOW vtec works on.
6) Car must be at I belive its 80 degrees or higher so let car get to a normal operating temprature.
7) If none of the above work, you might want to pull the solenoid off the head, remove the solenoid filter and verify the piston moves freely.
Thats a basic troubleshoot for it. if i missed anything or got anything wrong just reply and ill change the info.
If you go through all this and it still doesn't work its oil pressure (the pump) or wiring related. so check all the wires for vtec.
Thats it i hope it helps some people.
Joe
[Modified by KAMiN, 5:45 PM 6/5/2002]
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From: PASADENA, CA, USA
Re: VTEC Troubleshooting (KAMiN)
Ok, I have noticed ALOT of people recently asking about why their vtec isn't working. I'm just going to do some of the basic steps in checking to see why the **** vtec isn't working .
1) Oil level, its gotta be FULL. I'm talking at the upper mark on the dipstick.
2) Solenoid, Ok this is a 2 parter. A) take a wire (any wire) disconnect the grey plug on the vtec solenoid and touch the wire to the pos. battery terminal and the solenoid side of the grey 1 pin connector. there should be an audible click from the solenoid. B) If A checks out, remove the solenoid and clean the filter screen. (self explanatory)
3) Speed, the car must be going over 10 mph so the spedo must be working. that means the VSS has to be working. vtec is temperamental isn't it?
4) more oil, check the oil pan. if its dented POUND IT OUT!. this is why mine wasn't working. the pan was dented in far enough to hit the oil pickup for the pump to cause low pressure situation in the head, no pressure no vtec.
5) ECU Swap out to another ECU that you KNOW vtec works on.
Thats a basic troubleshoot for it. if i missed anything or got anything wrong just reply and ill change the info.
If you go through all this and it still doesn't work its oil pressure (the pump) or wiring related. so check all the wires for vtec.
Thats it i hope it helps some people.
Joe
. 1) Oil level, its gotta be FULL. I'm talking at the upper mark on the dipstick.
2) Solenoid, Ok this is a 2 parter. A) take a wire (any wire) disconnect the grey plug on the vtec solenoid and touch the wire to the pos. battery terminal and the solenoid side of the grey 1 pin connector. there should be an audible click from the solenoid. B) If A checks out, remove the solenoid and clean the filter screen. (self explanatory)
3) Speed, the car must be going over 10 mph so the spedo must be working. that means the VSS has to be working. vtec is temperamental isn't it?
4) more oil, check the oil pan. if its dented POUND IT OUT!. this is why mine wasn't working. the pan was dented in far enough to hit the oil pickup for the pump to cause low pressure situation in the head, no pressure no vtec.
5) ECU Swap out to another ECU that you KNOW vtec works on.
Thats a basic troubleshoot for it. if i missed anything or got anything wrong just reply and ill change the info.
If you go through all this and it still doesn't work its oil pressure (the pump) or wiring related. so check all the wires for vtec.
Thats it i hope it helps some people.
Joe
The car has to be at a normal operating temperatures in order for vtec to kick over, as well.
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Re: VTEC Troubleshooting (KAMiN)
i thought the speed had to be 19mph, plus the oil level doesnt have to be full, before i realised how much oil i was using i was running around for a week with the oil level not even registering on the dipstick, took almost 3/4 litre to bring it up to full, but the engine/vtec was working perfectly. I think the actual temp has to be 74 degrees before it will work.
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From: Seminole, FL, usa
Re: VTEC Troubleshooting (mugenracer)
At a pre-designated RPM, if and only if there is enough oil pressure , the CPU activates a solenoid. This causes a pin to lock the intake valves together creating a sudden jump in acceleration. To activate the second stage at 2500 rpm(both valves opening), oil pressure is diverted into a channel that drives a pin which connects intake valve rocker #1 with #2. Now, both intake valves are being operated in unison. This is perhaps not quite as ideal as a little valve stagger (as seen in the DOHC VTEC apps), but sufficient enough for good power.
To enter the third stage, at 6000 rpm, oil is now allowed into a second channel connecting all the rocker arms. This oil drives a pin which connects the linked #1 and #2 rockers to the center lobe actuated #3 rocker which is, of course, the high lift and duration mode.
Frankly, the implementation, from an engineering standpoint, is absolutely brilliant.
To enter the third stage, at 6000 rpm, oil is now allowed into a second channel connecting all the rocker arms. This oil drives a pin which connects the linked #1 and #2 rockers to the center lobe actuated #3 rocker which is, of course, the high lift and duration mode.
Frankly, the implementation, from an engineering standpoint, is absolutely brilliant.
Thread Starter
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From: Tucson, AZ
Re: VTEC Troubleshooting (mugenracer)
i thought the speed had to be 19mph, plus the oil level doesnt have to be full, before i realised how much oil i was using i was running around for a week with the oil level not even registering on the dipstick, took almost 3/4 litre to bring it up to full, but the engine/vtec was working perfectly. I think the actual temp has to be 74 degrees before it will work.
and for the oil, it can work at halfway up the dipstick, but its a good general rule to make sure its at the upper mark before you do anything drastic (like removing the solenoid)
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From: Sydney, Australia
Re: VTEC Troubleshooting (dkay040)
At a pre-designated RPM, if and only if there is enough oil pressure , the CPU activates a solenoid. This causes a pin to lock the intake valves together creating a sudden jump in acceleration. To activate the second stage at 2500 rpm(both valves opening), oil pressure is diverted into a channel that drives a pin which connects intake valve rocker #1 with #2. Now, both intake valves are being operated in unison. This is perhaps not quite as ideal as a little valve stagger (as seen in the DOHC VTEC apps), but sufficient enough for good power.
To enter the third stage, at 6000 rpm, oil is now allowed into a second channel connecting all the rocker arms. This oil drives a pin which connects the linked #1 and #2 rockers to the center lobe actuated #3 rocker which is, of course, the high lift and duration mode.
Frankly, the implementation, from an engineering standpoint, is absolutely brilliant.
To enter the third stage, at 6000 rpm, oil is now allowed into a second channel connecting all the rocker arms. This oil drives a pin which connects the linked #1 and #2 rockers to the center lobe actuated #3 rocker which is, of course, the high lift and duration mode.
Frankly, the implementation, from an engineering standpoint, is absolutely brilliant.
never had it explained better...?
t..
(PS is this true? it uses pins? are you talking about VTEC? isnt the third rocker a lost motion assembly?)
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From: Sydney, Australia
Re: VTEC Troubleshooting (dkay040)
yes it uses pin do u think i would just waste my time writing that for the hell of it
maybe if YOU wrote it...
http://integra.vtec.net/engine/vtec.html
cya,
t..
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From: Tucson, AZ
Re: VTEC Troubleshooting (tinkerbell)
yes it uses pin do u think i would just waste my time writing that for the hell of it
ROFLMAO!!!!!!!!!!!!!!!!!!!!!!!!!
maybe if YOU wrote it...
http://integra.vtec.net/engine/vtec.html
cya,
t..
ROFLMAO!!!!!!!!!!!!!!!!!!!!!!!!!
maybe if YOU wrote it...
http://integra.vtec.net/engine/vtec.html
cya,
t..
dont post other peoples stuff
Thread Starter
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From: Tucson, AZ
Re: VTEC Troubleshooting (MikeSarr_GSR)
6) Car must be at I belive its 80 degrees or higher so let car get to a normal operating temprature.
actually, you didnt forget.
actually, you didnt forget.
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From: Sydney, Australia
Re: VTEC Troubleshooting (crxfactor1991)
no, VTEC remains engaged whilst TP is where-ever,
for example, backing off down a hill at 6500rpm with throttle closed...
then boot it to WOT and VTEC is already engaged and you will nail it to redline...
is this what you sort of meant?
so i guess that throttle position does not have a effect on VTEC except for it needing to be open before you can get to VTEC
UNLESS you downshift into VTEC...
so actually, no, throttle position does not affect VTEC?!?!
am i right?
please consider...
t..
for example, backing off down a hill at 6500rpm with throttle closed...
then boot it to WOT and VTEC is already engaged and you will nail it to redline...
is this what you sort of meant?
so i guess that throttle position does not have a effect on VTEC except for it needing to be open before you can get to VTEC
UNLESS you downshift into VTEC...
so actually, no, throttle position does not affect VTEC?!?!
am i right?
please consider...
t..
Joined: Mar 2002
Posts: 799
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From: San Diego, CA
Re: VTEC Troubleshooting (dkay040)
At a pre-designated RPM, if and only if there is enough oil pressure , the CPU activates a solenoid. This causes a pin to lock the intake valves together creating a sudden jump in acceleration. To activate the second stage at 2500 rpm(both valves opening), oil pressure is diverted into a channel that drives a pin which connects intake valve rocker #1 with #2. Now, both intake valves are being operated in unison. This is perhaps not quite as ideal as a little valve stagger (as seen in the DOHC VTEC apps), but sufficient enough for good power.
To enter the third stage, at 6000 rpm, oil is now allowed into a second channel connecting all the rocker arms. This oil drives a pin which connects the linked #1 and #2 rockers to the center lobe actuated #3 rocker which is, of course, the high lift and duration mode.
Frankly, the implementation, from an engineering standpoint, is absolutely brilliant.
To enter the third stage, at 6000 rpm, oil is now allowed into a second channel connecting all the rocker arms. This oil drives a pin which connects the linked #1 and #2 rockers to the center lobe actuated #3 rocker which is, of course, the high lift and duration mode.
Frankly, the implementation, from an engineering standpoint, is absolutely brilliant.
Please explain to me how you get oil to travel selectively around vtec rocker arms pins. Have you ever taken apart a vtec head. I have taken apart quite a few, and I'll tell you, I've only found 1 path for the oil to take and I have yet to see it skip past the center to engage both outside rockers. For what reason somone would want to do this is beyond me since they always work and dont need to be engaged.
Im all about support and helping each other out, but if you dont know dont go and undo the help that others have provided.
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From: Sydney, Australia
Re: VTEC Troubleshooting (kinesistech)
hey kinesistech!
how goes it??
we are not sure where this guy gets his kicks from but we worked out he copies other peoples stuff and doesnt bother to read it before posting it.
oh well, some people gotta learn the hard way...
anyways,
im not sure i agree on the MAP bit.
the only reason VTEC doesnt engage whilst stationary is because of the VSS rule.
im pretty sure i have seen no litrature that links MAP to VTEC.
as i stated above TPS is not an VTEC input as you can be coasting down hill at 6500rpm and still have VTEC engaged, you dont get the sound, but when you snap hte throttle open, it hits straight up.
so i dont think VTEC disengages because of no load circumstances...
that is, VTEC engagement is not load dependent.
have i mis-interpreted what you were saying???
t..
how goes it??
we are not sure where this guy gets his kicks from but we worked out he copies other peoples stuff and doesnt bother to read it before posting it.
oh well, some people gotta learn the hard way...
anyways,
im not sure i agree on the MAP bit.
the only reason VTEC doesnt engage whilst stationary is because of the VSS rule.
im pretty sure i have seen no litrature that links MAP to VTEC.
as i stated above TPS is not an VTEC input as you can be coasting down hill at 6500rpm and still have VTEC engaged, you dont get the sound, but when you snap hte throttle open, it hits straight up.
so i dont think VTEC disengages because of no load circumstances...
that is, VTEC engagement is not load dependent.
have i mis-interpreted what you were saying???
t..
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From: somewhere out there, CA
Re: VTEC Troubleshooting (kinesistech)
At a pre-designated RPM, if and only if there is enough oil pressure , the CPU activates a solenoid. This causes a pin to lock the intake valves together creating a sudden jump in acceleration. To activate the second stage at 2500 rpm(both valves opening), oil pressure is diverted into a channel that drives a pin which connects intake valve rocker #1 with #2. Now, both intake valves are being operated in unison. This is perhaps not quite as ideal as a little valve stagger (as seen in the DOHC VTEC apps), but sufficient enough for good power.
To enter the third stage, at 6000 rpm, oil is now allowed into a second channel connecting all the rocker arms. This oil drives a pin which connects the linked #1 and #2 rockers to the center lobe actuated #3 rocker which is, of course, the high lift and duration mode.
Frankly, the implementation, from an engineering standpoint, is absolutely brilliant.
Yo, you must have the good drugs. The both valves always open, not one untill the "1st stage" which doesnt exist, if you actually look at it 2 cam lobes are always touching 2 rockers. Those are typically ALWAYS working. Also, how is it, do you suppose, that you can get three stages of vtec where oil is diverted here and there when there is only one vtec solenoid per engine.
Please explain to me how you get oil to travel selectively around vtec rocker arms pins. Have you ever taken apart a vtec head. I have taken apart quite a few, and I'll tell you, I've only found 1 path for the oil to take and I have yet to see it skip past the center to engage both outside rockers. For what reason somone would want to do this is beyond me since they always work and dont need to be engaged.
Im all about support and helping each other out, but if you dont know dont go and undo the help that others have provided.
To enter the third stage, at 6000 rpm, oil is now allowed into a second channel connecting all the rocker arms. This oil drives a pin which connects the linked #1 and #2 rockers to the center lobe actuated #3 rocker which is, of course, the high lift and duration mode.
Frankly, the implementation, from an engineering standpoint, is absolutely brilliant.
Yo, you must have the good drugs. The both valves always open, not one untill the "1st stage" which doesnt exist, if you actually look at it 2 cam lobes are always touching 2 rockers. Those are typically ALWAYS working. Also, how is it, do you suppose, that you can get three stages of vtec where oil is diverted here and there when there is only one vtec solenoid per engine.
Please explain to me how you get oil to travel selectively around vtec rocker arms pins. Have you ever taken apart a vtec head. I have taken apart quite a few, and I'll tell you, I've only found 1 path for the oil to take and I have yet to see it skip past the center to engage both outside rockers. For what reason somone would want to do this is beyond me since they always work and dont need to be engaged.
Im all about support and helping each other out, but if you dont know dont go and undo the help that others have provided.
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From: San Diego, CA
Re: VTEC Troubleshooting (tinkerbell)
You read me right, I think some one should try it Im not %100 postive though. put your VSS in a drill and disconnect MAP. I guess with any check engine lights the vtec doesnt work anyway huh. Oh well.
Spoon, no he is wrong. What he wrote makes no sense.
[Modified by kinesistech, 9:20 AM 6/5/2002]
Spoon, no he is wrong. What he wrote makes no sense.
[Modified by kinesistech, 9:20 AM 6/5/2002]
Thread Starter
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From: Tucson, AZ
Re: VTEC Troubleshooting (kinesistech)
You read me right, I think some one should try it Im not %100 postive though. put your VSS in a drill and disconnect MAP. I guess with any check engine lights the vtec doesnt work anyway huh. Oh well.
Spoon, no he is wrong. What he wrote makes no sense.
[Modified by kinesistech, 9:20 AM 6/5/2002]
Spoon, no he is wrong. What he wrote makes no sense.
[Modified by kinesistech, 9:20 AM 6/5/2002]
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From: san luis obispo, ca
Re: VTEC Troubleshooting (KAMiN)
Here's another fun one - disassemble the solenoid assembly and make sure the piston slides FREELY - last night I discovered that mine was completely bound up in one position.
