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Old 05-28-2012, 03:33 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

Originally Posted by H_T_LUDE
i appreciate the info you guys have posted, more useful than the manual i bought. However,
Perhaps someone could elaborate on what engine components could cause low oil pressure that would make for a delayed engaugement of the VTEC system.
I read above about the oil pan volume being decreased by dents, can this cause low oil pressure? my only concern is that im hitting VTEC at 6000rpm and its a strong pull but have felt more at that very same rpm a couple months ago.
Now im aware that the tollerance in the main bearing caps where the oiler spouts on the crank can have to much runout that cause low oil pressure and that perhaps the oil pump itself might have wear, but are there any other contributing factors or components that can cause a low oil pressure?
bad oil (thin) will pass smaller clearences faster causing lower pressure at the end of the channels. any leak or bad seal before the pump or after will cause it to draw in air before pump/ lose pressure after pump.
Old 05-28-2012, 03:37 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

Originally Posted by anonymus913
Hi ppl. I have a serious issue. My vtec just will not work. I'm throwing vss code. And that's the only cel I'm throwing. I changed it 3 times along with the cluster twice. Cluster reads rmp but not mph. Before my vtec used to work just fine. Alive n healthy. Then the mph gauge started jumping around and the vtec would cut in and out. Then the mph gauge stopped working and so did the tec. I'm lost. Help anyone? Btw motor has 60 thousand miles it's strong. Oh yea my rev limit is 6500
had an issue like this after i rebuilt my b18c1, the vss sensor at the top of the tranny was the issue. i had a bad connection due to forgetting to put a clamp on one of the coolant hoses under the itm. any short between that sensor and the ecu will cause it to "jump" or just plain not work.
Old 05-28-2012, 03:40 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

also check and adjust your valve lash. it's "supposed" to be done every 15,000 miles
Old 07-22-2012, 04:32 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

i have a 91 integra with a 94 gsr swap and my v tech hasnt worked since i got the car there was a copple CEL's but had them fixed due to the wrong ecu but i cant get the tps code to clear ive replaced the tps sensor with a new one and that didnt change anything, i even tested the new one and it was fine, i can unplud the sensor and nothing changes the wires seem to be in the right spot in the ecu im not quite shure what it could be kinda stumped atm so if any one has anyideas i would love to hear them
Old 07-23-2012, 06:38 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

Did you use a volt meter to properly calibrate the new tps? You can't just bolt the new one in place and expect it to work, you need to clock it correctly. 0.5v closed, 4.5v at wot.
Old 07-26-2012, 11:55 AM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

I have a 95 gsr in my eg hatch, and you can clearly hear my vtec crack at 5700..but you cant feel any sort of pull until I hit 7000rpm. But from 7000-8200 it pulls hard. My oil is full, and i just changed it yesterday. The only thing i can think of is timing? I havent checked my crank timing, and my dizzy is centered in the bolt holes. Would the crank timing cause the sluggishness?
Old 07-26-2012, 01:23 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

You have accidentally landed in the Prelude forum, for answers specific to your motor, try the Integra forum
Old 07-26-2012, 02:02 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

Oh wow, i didn't even see that. My bad, haha. Thanks
Old 12-22-2012, 07:30 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

bumping this up! iv read everything and nothing fits my symptoms!
98 gsr with b18c5 swap
i have an intermittent no vtec... here is what happens...
ill be driving fine (vtec working) and suddenly after awhile or pretty quickly my engine rpm's will jump up to exactly where it sits when its in "warming up mode" and i have no vtec!

the only way to fix this is turn my car off and start her back up again. after i do this my rpm's go back down to normal and everything works!

please help! thank you

(sorry was searching on google and this came up and i didnt realize this was the prelude sections hahaha) pretty much the same **** anyway..
Old 09-15-2013, 02:30 AM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

i have a very similar problem. i have a 94 accord sir with an h22a motor. vtec doesnt seem to be engaging and revs are limited to about 6000rpm i have no CEL's i unplugged the vtec solinoid and it gave me a CEL and 5k rpm plugged back in and it went back to 6k. its supposed to rev cut at 7800rpm tho? its an auto btw if that makes a diff. i also have made my own troubleshooting thread if you want to check it out: https://honda-tech.com/forums/honda-accord-1990-2002-2/accord-sir-h22a-possible-problems-3170006/
Old 10-10-2013, 06:38 PM
  #136  
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Default Re: The Official "Why VTEC doesn't Engage" Thread

im having this problems.
it wont pass up 4k rpm. change the dizzy, vtc solenoid and try my ecu from friend ca and it works..
Old 04-24-2015, 05:53 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

Hi, im new to the forums .
I am having a problem with my 97 accord lx vtec after i swapped out the f22b2
For an f22b1
Whenever i start my cAr the vtec works great for about 5 minutes or so and the it completely cuts out
I have no cel, and if i turn the car off and back on , even while rolling the vtec works again
I really just cant figure out my problem
Old 06-02-2015, 07:27 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

I tool my wife's 96 Accord Wagon to the dealer to inspect the front end and engine mounts. On the way out, I had to turn back because I was lacking power and limiting at 5k RPM.
The mech said it may be a cat. conv. and wanted $125 to diagnose.

Several weeks later:
There are NO CEL OR CODES!
Except when I intentionally unplug the TPS, MAP or VTEC Solenoid.


This thread says a BENT OIL PAN can limit the flow and put the limiter in effect WITHOUT GIVING A CEL or CODE!

I just got back from the DEALER (Capitol Honda San Jose) and they tell me there is "NO PROBLEM." WTH?????!!!!!

Any suggestions would be helpful. The oil pan IS DENTED so I plan to try to straighten it through the Drain Plug. May not work.

May be able to UN-DENT without removing the Exhaust Header???

Also: If it's Low Oil Pressure possibly related to the VTEC, and the OIL Light never lights (except check)... shouldn't I get a VTEC Fault Code?

Can the Vtec Pressure Sensor Cause a Limit at 5k without telling us why??? Maybe so...

SUGGESTIONS WELCOME! THANKS!!!


Stan P.
please email: stanplock@att.net

I want to take the wagon to Yosemite in a few weeks. Or squeeze 5 people in my Civic for 4 hours each way.

I posted in another thread also. (Doesn't seem to be common to Prelude.) Sorry for posting here but this thread may have my answer. THANKS!

The dealer CHANGED the OIL but it made no difference.
Old 06-03-2015, 04:58 PM
  #139  
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Default Re: The Official "Why VTEC doesn't Engage" Thread

IDEA:
It seems that it can ONLY be the VTEC PRESSURE SENSOR that causes Limp Mode with NO CEL Code.

Is there any other sensor besides the idiot light sensor that could do that?
Except those that give codes.

I can monitor the voltage across the Vtec Pressure Sensor and go for a spin to see if the voltage goes to 10 V or so when the problem occurs.

I'll report back...

OK... The 96 Accord Wagon does NOT have a Vtec Pressure switch.
So what is causing Limp Mode???

Before I un-dent the oil pan, I'd like this to make sense.

I'll report back...

Last edited by Stan_P; 06-03-2015 at 05:46 PM.
Old 06-04-2015, 07:27 PM
  #140  
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Default Re: The Official "Why VTEC doesn't Engage" Thread

My 96 Accord Wagon started 5k limiting after visiting the dealer for an inspection. I may have had an oil change and maybe they put in Thin Oil??? Motor has 220,000 mi.

This Accord has NO Vtec Pressure Sensor Switch???
Just a bolt. (I saw same on ebay.) And No Connector for a Pressure Sensor in the harness. Nothing has been changed.

It rev limits at 5k RPM. Dealer says it's OK like that. Didn't bother to run any diags.

Vtec draws .8Amps from 12V (battery) or above 2500 RPM (connected normally).

Disconnecting the Vtec Solenoid lights the CEL and I NO Longer get Current to the Solenoid with the CEL on. Vtec is off until ECU is reset.

Someone reported that Rev Limit should be off and they can now rev up OK. But mine still rev limits with Vtec CEL fault on.

I know the Vtec is actually functioning because the engine power is much lower with the CEL light on.
But I still get 5K limit with NO Codes.
I did get an O2 fault when I was disconnecting stuff. Will check that first.

Suggestions welcome.
Will try to report findings / fix.

___________

Note: "Limp Mode" is also used to describe problems at low RPM.
Like no power to heated O2 Sensors.

Maybe we should say "Rev Limiting" (@5K) instead?

As far as "vtec not engaging"... that doesn't seem to be the case with my Rev Limit Symptom.
Vtec seems to kick in at 2500 and is very noticeable when disconnected. Gives CEL code. Shuts off.

At this point I'm just going to start manually checking sensors with meters.

I may try thicker oil.

Best Wishes,
Stan P.

Last edited by Stan_P; 06-04-2015 at 07:55 PM.
Old 10-28-2015, 09:42 AM
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Default Re: The Official "Why VTEC doesn't Engage" Thread (soopafly828)

Originally Posted by the_eyecon
that is incorrect. VTEC does not work off the VSS, it works off of your tachometer. When you hit 5200-5400 RPM's VTEC activates, but the VSS does not effect VTEC.

'Con
I have a problem with my vtec it stopped working the night that my speedometer stopped working too..
So I think that vtec works with oil pressure but with speedometer also that's why vtec doesn't kick in when your car is on neutral and doesn't move when I solve the problem I will tell you for sure
Old 08-13-2016, 09:16 AM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

2000 Accord I blew the motor up and and replaced it with the same model . Vtec wasn't working at 4000rpm had it fixed a few times with the same issue. I was told that I wasn't making enough oil pressure try all different types of oil weights to bring the pressure up and still nothing finally took it to Honda. Honda got it fixed by then now the car overheat and pulled the thermostat out and VTEC started working again but kept doing with overheating. Turned out the temperature switch wire was corroded I replace that no more overheating but now I'm dealing with the issue refilling my radiator every couple of days because it's draining or burning off so how the smell of burning oil with no visible leaks anywhere and VTEC is back to not working at 4000 RPM help if anything please
Old 08-15-2016, 05:01 AM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

Originally Posted by toadtwenty2prod
2000 Accord I blew the motor up and and replaced it with the same model . Vtec wasn't working at 4000rpm had it fixed a few times with the same issue. I was told that I wasn't making enough oil pressure try all different types of oil weights to bring the pressure up and still nothing finally took it to Honda. Honda got it fixed by then now the car overheat and pulled the thermostat out and VTEC started working again but kept doing with overheating. Turned out the temperature switch wire was corroded I replace that no more overheating but now I'm dealing with the issue refilling my radiator every couple of days because it's draining or burning off so how the smell of burning oil with no visible leaks anywhere and VTEC is back to not working at 4000 RPM help if anything please
Old 10-20-2016, 04:48 PM
  #144  
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Default Re: The Official "Why VTEC doesn't Engage" Thread

I have a question. I'm just now getting into this whole Honda deal. I've bought and sold over 100 5th Gen Accords. I'm not running any major mods. I have a factory 94 Accord coupe VTEC. Picked the car up for 350 bucks because it needed a water pump and a clutch. I'm very familiar with factory repairs (been a tech for 12 years). I've notice that it doesn't feel like the VTEC is kicking in. I'm under the assumption that it should kick in around 4600 RPMs. The car has not been swapped. This is a SOHC F22. I'm seeing alot about the VSS playing a role in VTEC engagement. My speedo doesn't work due to the all too common cluster failure. Could this affect VTEC engagement?

Last edited by Josh Crawford; 10-20-2016 at 04:58 PM. Reason: Spelling error
Old 10-20-2016, 08:25 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

Originally Posted by Josh Crawford
I have a question. I'm just now getting into this whole Honda deal. I've bought and sold over 100 5th Gen Accords. I'm not running any major mods. I have a factory 94 Accord coupe VTEC. Picked the car up for 350 bucks because it needed a water pump and a clutch. I'm very familiar with factory repairs (been a tech for 12 years). I've notice that it doesn't feel like the VTEC is kicking in. I'm under the assumption that it should kick in around 4600 RPMs. The car has not been swapped. This is a SOHC F22. I'm seeing alot about the VSS playing a role in VTEC engagement. My speedo doesn't work due to the all too common cluster failure. Could this affect VTEC engagement?
According to what i've read on here n heard from others, vtec might not work properly if your vss or tachometer arent working properly. Besides needing good oil pressure once the engine is warm, i believe the ecu needs the speedometer/vss and tachometer reading as a reference or signal to activate vtec. READ THE FIRST PAGE OF THIS THREAD ON SYMPTOMS WHY VTEC WON'T WORK.
Old 10-22-2016, 11:59 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

Originally Posted by Josh Crawford
I have a question. I'm just now getting into this whole Honda deal. I've bought and sold over 100 5th Gen Accords. I'm not running any major mods. I have a factory 94 Accord coupe VTEC. Picked the car up for 350 bucks because it needed a water pump and a clutch. I'm very familiar with factory repairs (been a tech for 12 years). I've notice that it doesn't feel like the VTEC is kicking in. I'm under the assumption that it should kick in around 4600 RPMs. The car has not been swapped. This is a SOHC F22. I'm seeing alot about the VSS playing a role in VTEC engagement. My speedo doesn't work due to the all too common cluster failure. Could this affect VTEC engagement?
If your speedometer doesnt work it defenately affects your VTEC engagement its sure cause i had the same issue
Old 03-08-2017, 08:09 AM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

Hi, I'm new to the forums and have done a lot of reading up on this issue but can't seem to "solve" it. But I have a P1259 code I've been struggling with for awhile. I have an '01 Civic EX 1.7L (all stock) with 192k miles. Just to make aware, I did a head gasket/water pump/timing belt replacement awhile back and car ran good but at certain RPM the car would hop (around VTEC rpm, almost like I hit the rev limit early - about 3k) so I took the VVT sol off and found crap in the filter screen. Replaced the screen and that solved the "hopping" issue but doesn't fix the P1259 code. Checked oil levels, changed oil, Changed the VVT sol (tested to make sure sol we're working and both work), changed oil pressure switch, checked wiring from ECU to each the VVT sol and the pressure switch and wires are good to the computer. Changed the connectors on both the sol and the pressure switch just cause I noticed a crack in one of them. Nothing seemed to "fix" it so I'm having a hard time believing it's electrical but not ruling anything out at this point. I tested the oil pressure by removing the oil pressure switch on the VVT sol housing and piped in a 100psi gauge. rev'd the car to 3k RPMS (don't read any oil pressure until I and jumped the VVT sol to the pos off the battery to activate it) but only at 3k RPM I only had about 25-30psi. Did the test again only at 4K RPM and hit the limp mode rev limit and only had about 40psi. Reconnected all connectors and removed the gauge and was able to rev the car to 5K RPM before hitting a rev limit. Was told I should have 60psi at 3k RPM with no load on the car (reving engine sitting in park) but I'm not even close to that. Is there anywhere else besides the oil pressure switch I can read the oil pressure? if I check it at the oil filter housing, what kind of pressure should I see? I drove the car like this for a week to work and back and it runs GREAT, but the CEL light won't go away and I can't get it inspected till I take care of this headache. Any help is much appreciated. Thanks in advance!
Old 06-14-2017, 01:31 AM
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Default Re: The Official "Why VTEC doesn't Engage" Thread (prelittlelude)

Hey y'all
I have a question
I own 1990 Acura integra
has a b16a engine with obd0 ecu
when i run the car vtec don't work and my engine light get on
I get cel 23 witch is knock sensor when I buy the car the ks was broke so I changed
but im still getting same code
the engine has some bad things
my lost motion assembly are bad i do a valve adjustment and I found out there bad
i run the car some days I go and my oil light turns on
my o2 sensor it's not connected previous owner cut the wire
I used chippes gas so now I know I have to run 93 octane
i found out today that one of my ingectors looks cain wet
the car has aftermarket exhaust and it's licking from catalytic converter
and longer I own used 2 o2 sensor but the headers don't have the plug for sensor
and my oil pan has some scratches I'm not really sure if has a oil licking.
Help
Old 06-04-2023, 01:56 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

Hello i have a boosted 1990 ef hatch swaped and with a b18 block and b16 head. vtec will not engage when it tries to engage it breaks up really bad and i cant get past 5500 rpms. i have fixed oil pressure replaced orings in the head adjusted timing swaped solenoids swaped the ecu and tested if the rocker arms would lock. we are running on hondata s300 on a p28 ecu we changed the vtec engagement window and it does the same thing but set to the later window. PLEASE HELP!!!!
Old 06-04-2023, 07:29 PM
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Default Re: The Official "Why VTEC doesn't Engage" Thread

Originally Posted by Tremer
Hello i have a boosted 1990 ef hatch swaped and with a b18 block and b16 head. vtec will not engage when it tries to engage it breaks up really bad and i cant get past 5500 rpms. i have fixed oil pressure replaced orings in the head adjusted timing swaped solenoids swaped the ecu and tested if the rocker arms would lock. we are running on hondata s300 on a p28 ecu we changed the vtec engagement window and it does the same thing but set to the later window. PLEASE HELP!!!!
... And you posted this in the "Prelude" sub-forum why exactly ??? Try another "known good" ECU.
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