really need help... built ls vtec will not hit vtec no matter what
#1
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really need help... built ls vtec will not hit vtec no matter what
i honestly hate asking these stupid questions because i usually know the answer....
but today i dont...
motor is b18b1 block with pr3 b16 head skunk 2 tuner 2 cams skunk 2 springs and retainers skunk 2 pro intake manifold hi end try y header itr pistons
so my question.. my friend has an ls vtec with itr pistons and skunk 2 tuner 2 cams and he asked me to tune it so i went over and started street tuning... the first night car was engaging vtec all night, then the next day it started hitting vtec late i had vtec set at 5700 rpms and it wasnt engaging till 6400 rpms, were only spinning the motor to 8000 rpms...
so the other day i go to retune the ecu to see what happened and i set the vtec at 5700 again and we went to take it for a test run and no vtec at all... so i thought maybe i pulled a wire on the ecu or something, so i ran the wire to the brights and no vtec ...
no matter what i do it will not engage vtec at all, i pulled the vtec solinoid off and had him start it and it shot oil up abut 2 feet i put 3 different vtec solinoids on it and still nothing..
i took the cam caps off and replaced the middle dowel pin and rubber o ring and still no vtec...
i am really stumped can anyone shed some light, i took the cams out and all the rockers and all the parts are there but still no vtec...
tomorrow im going to get an oil pressure guage because im starting to think it is an oil pump issue
if anyone has any ideas i would really appreciate it this car was running good and had awesome power but now it just feels like a built ls
but today i dont...
motor is b18b1 block with pr3 b16 head skunk 2 tuner 2 cams skunk 2 springs and retainers skunk 2 pro intake manifold hi end try y header itr pistons
so my question.. my friend has an ls vtec with itr pistons and skunk 2 tuner 2 cams and he asked me to tune it so i went over and started street tuning... the first night car was engaging vtec all night, then the next day it started hitting vtec late i had vtec set at 5700 rpms and it wasnt engaging till 6400 rpms, were only spinning the motor to 8000 rpms...
so the other day i go to retune the ecu to see what happened and i set the vtec at 5700 again and we went to take it for a test run and no vtec at all... so i thought maybe i pulled a wire on the ecu or something, so i ran the wire to the brights and no vtec ...
no matter what i do it will not engage vtec at all, i pulled the vtec solinoid off and had him start it and it shot oil up abut 2 feet i put 3 different vtec solinoids on it and still nothing..
i took the cam caps off and replaced the middle dowel pin and rubber o ring and still no vtec...
i am really stumped can anyone shed some light, i took the cams out and all the rockers and all the parts are there but still no vtec...
tomorrow im going to get an oil pressure guage because im starting to think it is an oil pump issue
if anyone has any ideas i would really appreciate it this car was running good and had awesome power but now it just feels like a built ls
#2
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Re: really need help... built ls vtec will not hit vtec no matter what
Did you check the oil? i had this issue in my car. i didnt realize i was burning oil untill it happened. i would get in it and vtec wouldnt kick in cause it couldnt make the oil pressure.
then higher in the rpm it would kick on. u might wanna check it. and grab a pressure gauge like ur gonna do, to make sure.
then higher in the rpm it would kick on. u might wanna check it. and grab a pressure gauge like ur gonna do, to make sure.
#3
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Re: really need help... built ls vtec will not hit vtec no matter what
yes the oil is full the car doesnt really burn oil its still pretty much brand new i think it has about 3k miles on it but i think they re used the old oil pump
#5
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Re: really need help... built ls vtec will not hit vtec no matter what
right now i have the vtec on a 12 volt switch right now it is not engaging no matter what i do...
tomorrow im going to put a mechanical oil pressure guage on the motor and see whats going on... is it possible that the oil pump is cavitating at high rpms?
tomorrow im going to put a mechanical oil pressure guage on the motor and see whats going on... is it possible that the oil pump is cavitating at high rpms?
#6
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Re: really need help... built ls vtec will not hit vtec no matter what
anybody else have any ideas, ive already pulled the head apart took the cams out took the rockers out and everything looks okay just dont understand why no vtec
#7
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Re: really need help... built ls vtec will not hit vtec no matter what
time to try another vtec solenoid...have you even pulled the solenoid off to check the screen?
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#8
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Re: really need help... built ls vtec will not hit vtec no matter what
reading can be a bitch
#9
Re: really need help... built ls vtec will not hit vtec no matter what
He said in the first post that he tried 3 different vtec selonoids .. What's the chance that all 3 were bad ?
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Re: really need help... built ls vtec will not hit vtec no matter what
Is your ecu throwing any codes? Some fault codes will put the ecu in limp mode and shut out the vtec system. The ecu uses the speed sensor primary o2 sensor tps sensor and coolant temp sensors all to make sure the conditions are safe for vtec to activate, If any of these are bad/ disconnected you get no vtec.
If thats not it you most likely have a oil pressure issue.
with any rebuilt motor theres always a chance debris and crud from assembly and break in can clog up passages in the head, and the orfices thta go to the rocker shafts are tiny.
Lastly pop the valvecover off and check the valvelash. Too tight you get valves opening too early causing low comperssion readings, too tight they open late and make tons of noise, and cause a misfire to be picked up at the ecu.
One thing I almost forgot is knock sensor. Most ls vtec motors have them disabled, If its still on I believe it would do that too, But may not have worked from the git go.
Hope my ramblings help some... In for results
If thats not it you most likely have a oil pressure issue.
with any rebuilt motor theres always a chance debris and crud from assembly and break in can clog up passages in the head, and the orfices thta go to the rocker shafts are tiny.
Lastly pop the valvecover off and check the valvelash. Too tight you get valves opening too early causing low comperssion readings, too tight they open late and make tons of noise, and cause a misfire to be picked up at the ecu.
One thing I almost forgot is knock sensor. Most ls vtec motors have them disabled, If its still on I believe it would do that too, But may not have worked from the git go.
Hope my ramblings help some... In for results
#13
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Re: really need help... built ls vtec will not hit vtec no matter what
okay im going to say this one more time because posts saying anything about check engine lights or anything to do with the ecu have nothing to do with my problem
I HAVE VTEC WIRED TO A 12 VOLT SWITCH, SO WHENEVER I PUT THE SWITCH IN THE ON POSITION VTEC SHOULD TURN ON... BUT IT DOESNT
so please stop suggesting anything with sensors or ecu or anything... right now there is a malfunction in the vtec system itself or oil pressure or something of that matter i have no idea because like i said i removed everything that had to do with vtec and cleaned it, including all the rockers and re installed them and took off the whole vtec solinoid and the bottom part of it too that attatches to the head and cleaned it... i cleaned everything all the rockers all the cam caps and the top parts that hold the cam caps down where they have little holes for oil pressure everything is clean and flowing good
AND STILL NO VTEC
and if you have a problem understanding what 12 volts will do... go get a piece of wire, jump it from the battery to the vtec solinoid and you will hear a click... now this is what i have but i have a switch in the middle so i can turn it off and on
im not trying to belittle anyone or anything i am just really frustrated with this car and i have no idea what the problem could be
I HAVE VTEC WIRED TO A 12 VOLT SWITCH, SO WHENEVER I PUT THE SWITCH IN THE ON POSITION VTEC SHOULD TURN ON... BUT IT DOESNT
so please stop suggesting anything with sensors or ecu or anything... right now there is a malfunction in the vtec system itself or oil pressure or something of that matter i have no idea because like i said i removed everything that had to do with vtec and cleaned it, including all the rockers and re installed them and took off the whole vtec solinoid and the bottom part of it too that attatches to the head and cleaned it... i cleaned everything all the rockers all the cam caps and the top parts that hold the cam caps down where they have little holes for oil pressure everything is clean and flowing good
AND STILL NO VTEC
and if you have a problem understanding what 12 volts will do... go get a piece of wire, jump it from the battery to the vtec solinoid and you will hear a click... now this is what i have but i have a switch in the middle so i can turn it off and on
im not trying to belittle anyone or anything i am just really frustrated with this car and i have no idea what the problem could be
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Re: really need help... built ls vtec will not hit vtec no matter what
lol if you have it hooked straight to the solenoid then the solenoid is junk or you r hooking it up wrong
If the power is hooked straight up to the solenoid it should turn on no matter what oil pressure, temperature, etc
Test the solenoid off the car and see if it clicks
If the power is hooked straight up to the solenoid it should turn on no matter what oil pressure, temperature, etc
Test the solenoid off the car and see if it clicks
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Re: really need help... built ls vtec will not hit vtec no matter what
No need to get upset bro, it's only a suggestion and you are the one asking for advice. But anyhow... with that, your problem has to be mechanical. So it's time to open the head up. You were not the one who assembled the motor correct? Double checking previous work is never a bad choice. Its typical of people to gob the he'll put of the oil pump pan and valve cover gaskets with rtv or hondabond so there's a possibility a nugget could have broke loose and gotten caught up in the vtec oil orfaces up top. Another reason to open it up is to check the o rings on the orfaces because if they were re used they could have either torn and be leaking or fell out during installation.
#16
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Re: really need help... built ls vtec will not hit vtec no matter what
Also, correct me if I'm wrong, but doesnt the solenoid use a negative/ ground signal to activate it? Rather than +12 volts?
#17
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Re: really need help... built ls vtec will not hit vtec no matter what
if you want to know why i get so upset is because there is all these posts of people putting up options, yes i am happy that people are helping, but if they can just read what i wrote in the beggining there would be no need for their post, because its NOT an ecu problem it is NOT an electrical problem its either something with the head or an oil pressure problem BECAUSE
WHEN I FIRST STARTED TUNING THE CAR VTEC WAS ENGAGING WITH NO PROBLEMS AT ALL.. YES VTEC WAS WORKING, THEN IT STOPPED WORKING... i replaced the vtec solinoid WITH 3 DIFFERENT ONES THAT I KNOW WORK
YOU ARE WRONG
#18
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Re: really need help... built ls vtec will not hit vtec no matter what
Hey man its obvious your problem is not electric.
Its an oil pressure problem it has to be. The most common i have seen is the oil pan being hit up against the oil pick-up. On my p72 head there is a little 10mm bolt that can be removed by the oil solenoid. I plug in a oil pressure gauge here then set vtec engaging speed (VSS) to 0mph and make sure water temp (ECT) is above activation level and rev up the motor.
Or you could just bring your rpm to 4000 and manually switch the solenoid and view the oil pressure gauge
it should read avove 57psi when activated.And no oil pressure when switched off.
Its an oil pressure problem it has to be. The most common i have seen is the oil pan being hit up against the oil pick-up. On my p72 head there is a little 10mm bolt that can be removed by the oil solenoid. I plug in a oil pressure gauge here then set vtec engaging speed (VSS) to 0mph and make sure water temp (ECT) is above activation level and rev up the motor.
Or you could just bring your rpm to 4000 and manually switch the solenoid and view the oil pressure gauge
it should read avove 57psi when activated.And no oil pressure when switched off.
Another test you can do to check the machanics of the vtec system is first remove the rocker cover and block the oil hole inside the head by the vtec soleniod.Connect a compressor with approx 60psi regulated air pressure to the 10mm removable port/bolt by your vtec solenoid. Then rotate the motor by hand and check that your middle/vtec rocker arms are locking one by one.
thankyou
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Re: really need help... built ls vtec will not hit vtec no matter what
that doesnt even make sense...how the fukc is something going to activate with a ground? wow, the misinformation on this site is enough to make me punch a baby
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Re: really need help... built ls vtec will not hit vtec no matter what
you need to do some research on what a ground switch is...when you have 12v going to a solenoid all the time u tap the ground and it completes the circuit...this is called a ground switch...i didnt read the whole thing but did u try bypassing the oil pressure switch....bridge a4 and d6 and then connect to vtec solenoid wire...disconect plug from oil pressure switch on vtec solenoid....
#21
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Re: really need help... built ls vtec will not hit vtec no matter what
you need to do some research on what a ground switch is...when you have 12v going to a solenoid all the time u tap the ground and it completes the circuit...this is called a ground switch...i didnt read the whole thing but did u try bypassing the oil pressure switch....bridge a4 and d6 and then connect to vtec solenoid wire...disconect plug from oil pressure switch on vtec solenoid....
i have only gotten 1 significant answer from the same person everything else on here really doesnt have anything to do with my problem and its really just a waste of time...
so before people keep posting up useless information please just read the post from the beginning
like i said im sorry i really dont want to be an ******* but i put up all the information of what i have already done to fix it and it hasnt helped... suggesting stuff that has nothing to do wtih my problem doesnt help either
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Re: really need help... built ls vtec will not hit vtec no matter what
You can also just flip the switch while the engine is off and listen if it engages
#23
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Re: really need help... built ls vtec will not hit vtec no matter what
OP- as far as your issue goes, Try the suggestion about locking the vtec rockers with air pressure...
As stated, removed the oil pressure service port on the solenoid and introduce air pressure. You can use an air blower/gun with a rubber tip so you dont have to mess with matching up fittings...
Removed the valve cover,plugs, and ecu fuse so fuel and spark arent active.
Have a buddy crank the car and watch the vtec lobes as the engine rotates. Youll know if you have a rocker arm issue...If all that checks out, hook up an oil pressure guage...
Good luck!
BTW- Have you tried a new vtec solenoid?
lol, im just kidding!
#25
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Re: really need help... built ls vtec will not hit vtec no matter what