ok, so my car (90 crx b16a swap) is acting weird. i was driving in 2nd gear trying to pass someone and i hit vtec at 5500 and at about 6000 it accelerated way slow. wtf. it was like driving with the vtec set at an unreachable point. thats exactly how it feels. i just fixed a major exhaust leak so could that have something to do with it? im kinda worried. its over due for an oil change too. any help is appreciated. thanks in advance.

 

is the car low on oil? low oil pressure would cause vtec not to engage.
how about the car's running temp. when you were driving? was it warmed up all the way to normal operating temp? that could also cause it

a fixed exhaust leak would only HELP your car and it'd probably make vtec more noticeable

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USDMSiR &raquo;</TD></TR><TR><TD CLASS="quote">its over due for an oil change too </TD></TR></TABLE>

 

im going to change the oil and oil filter today after work and see what happens. as far as temp goes it was at full op temp cause i was driving for about 20 min on the freeway and anyone with a b16 tranny knows that 70 mph sits at just above 4000 rpms. lol thanks guys

 

Yeah man,if its low on oil vtec will do that on/off stuff..

Do you have a check engine light on? or is the ecu throwing codes?

 

i changed the oil. it still does it. the car drives fine normally. it pisses me off. i do have a cel. i thought it was normal. and this might be a n00b question but how would i check if my ecu was throwing codes?

 

its pretty easy...u need to lift the passenger side carpet by the kickpanel and locate ur ecu...once u foun it...put ur key to the on position...this will cause a light on ur ecu to start blinking...long blinks count as 10 and short blings are 1....two long blinks and two short blinks will be a code 22...get it?
once u have the code it will be easy to solve...
have u tried cleaning ur vtec solenoid or grounding the pressure switch to the chassis?

 

ok, i dont know about the pressure switch and what not but im throwing codes 3,17,21,22, and 2.

 

Sounds like you might havce a bad ground, that can cause the ecu to throw a grip of codes. Try unhooking battery for a min and plug it back in see if that helps. With a cel the car goes into a safe mode and will not engage vtec.

 

ok, but ive had a cel ever since i got the car back (december or so) and its always hit vtec hard and fast. lol. but ill try that. anyother suggestions? im going to clean the vtec solenoid and see if thats it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USDMSiR &raquo;</TD></TR><TR><TD CLASS="quote">ok, i dont know about the pressure switch and what not but im throwing codes 3,17,21,22, and 2. </TD></TR></TABLE>

Wow if those are the codes you're throwing than you have some problems..

3=map sensor
17=vehicle speed sensor
21=vtec solenoid
22=vtec pressure switch
2=o2 sensor

from that it sounds like the previous owner didnt do a good job with wiring..cause i highly doubt all those things just went wrong all the sudden...Check over all the wires leading to those components 1st..

and make sure the speed sensor is plugged into the tranny,and into the back of the gauge cluster.

 

ive never had the speed sensor plugged in and my speedometer has never worked but vtec has always engaged. expletive, this is gay. oh well, looks like ill be busy this weekend.

 

i could be wrong, but i believe the ground for most of those is the wire on the thermostat housing, id check that ground, otherwise, sounds like the guy who did your motor swap really hacked the wires to hell

 

i bet thats it. the guy that did my swap is a professional and i highly doubt he just hacked and ****. he built a 9 sec crx soo he knows his ****. plus i changed the thermo recently so ill see if i can reground that and get back to ya'll. thanks guys. honda-tech=

 

ok so i found an old pr3 laying around and i decided to throw that in there. now im only getting 3 17 and 21. and vtec is engaging fully now. but im still confused and would like help on what to do as far as these other codes.

 

vtec is engaging with a cel for vtec, hmmmmmm odd....anyways, so it looks like your down to two, which is better....cuz the speed sensor light is on because your speedometer doesn't work, cuz on your cluster the speed signal is sent from the guage itself....but anyways....try swapping out a good known map sensor or check your vacuum line...sounds like u may have a bad one...and as for the vtec solenoid...id try and do the same, but i guess if its workin u can't really complain...but im one of those people that cant stand a check engine light being on, it bugs the hell outa me

 

this is more then strange, vtec dose not engage when
Solenoid
VSS
Pressure switch

codes are comming, you must have a chipped ECu,

 

i have a vafc2. no chip. lol. but i will try to find a known good map sensor and see whats up.

 

Check you ECU and se if its throwing any codes!

 

QUOTE=USDMSiR]ok, i dont know about the pressure switch and what not but im throwing codes 3,17,21,22, and 2. [/QUOTE]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USDMSiR &raquo;</TD></TR><TR><TD CLASS="quote">ok so i found an old pr3 laying around and i decided to throw that in there. now im only getting 3 17 and 21. and vtec is engaging fully now. but im still confused and would like help on what to do as far as these other codes.</TD></TR></TABLE>
read the whole thread n00bie.

 

Wont vfac engage vtec even if the ecu is in limp mode?? Sounds like to me that when they did your swap they ran those wires to the vfac and not to the ecu, i don't have experience with vfac but someone want to confirm my theory?

OP check your wiring for those sensors see where they lead too

 

i tried but i suck at tracing. ill give it a good shot next weekend cause im out of town this weekend.

 

im pretty sure it runs in parallel with the wire because otherwise running a vafc would cause your cel to come on and my friend has a vafc and his cel isn't on....but that would explain why vtec is kickin in even tho the light is on....and that also most likely explains why your cel is on for the map sensor, cuz vafc's are run in series with the map sensor signal wire to the ecu....so sounds like there is a problem....if it were me, i would just do away with the vafc...

 

yeah thats what i want to do but everytime i unplug the vafc it runs like ***, and runs rich. do you think a map sensor is the cause of this? cause as soon as my ecu stops throwing codes and i wire my jdm guage cluster (so the vss is wired) then i want it out of there.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nappyroots827 &raquo;</TD></TR><TR><TD CLASS="quote">im pretty sure it runs in parallel with the wire because otherwise running a vafc would cause your cel to come on and my friend has a vafc and his cel isn't on....but that would explain why vtec is kickin in even tho the light is on....and that also most likely explains why your cel is on for the map sensor, cuz vafc's are run in series with the map sensor signal wire to the ecu....so sounds like there is a problem....if it were me, i would just do away with the vafc...</TD></TR></TABLE>

Yea I am suggesting that the installer didn't just splice off the wires but actually cut them and ran them to the vfac instead of the ecu...and I think you agree that could possible cause this problem

You just gonna have to get down and dirty and try and see if the wiring is correct