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nismo

Junior Member
Hi
Here is the story
I had 92 Crx with swapped stock b16 in it.the engine itself did not have a knock sensor ,and I always had cel 23,but everything was working perfect including vtec.
Recently I swapped in a b20vtec(it is newly build engine with 1500 miles on it,it does not have a knock sensor ether),and now the vtec is working from time to time.When it is not working, the car would not rev past 7000.I have checked everything: oil pressure and level,vtec solenoid,ground,even checked for loosen pins in ecu,nothing seems wrong.Once when I checked vtec signal voltage from ecu,it was 11 something all the way from 0 to the red line,but just once. And just after I checked everything once again,the car started to run perfectly,but after one hour or so, vtec died again.What the hell could it possibly be? Any ideas?
Thanks.
 
When it works, are you alone? Did you forget to put the ECU cover back in? If you didnt then maybe the wires are moving with the ecu does nad causing it to loose its signal. My friend ef9civicgen four had the same problem, I gave him a cover to put over the ecu, and VTEC always kicks in now!
 
lol, that sounds like a ghetto ass fix if i ever heard one
lol

all i can tell you is make sure the computer is bolted down properly so its grounded correcty...
 
Originally posted by SpodaB1@Apr 1 2004, 08:41 PM
When it works, are you alone? Did you forget to put the ECU cover back in? If you didnt then maybe the wires are moving with the ecu does nad causing it to loose its signal. My friend ef9civicgen four had the same problem, I gave him a cover to put over the ecu, and VTEC always kicks in now!

Well,when it works the cover is on sometime,and sometime it is off.I have tried different combination,I even glued the wires with glue gun ,so there is no way for them to loose. Could it be becouse I do not have a knock sensor?

P.S. I even relocated the battery in the trunk,and changed all the groundings,it seemed to help ,but just for one run
 
Originally posted by nismo@Apr 2 2004, 12:36 AM
I even glued the wires with glue gun ,so there is no way for them to loose.


there's your problem...you bought the wrong gun...next time buy a soldering gun or iron...which ever you prefer ;) :p
 
Your not haveing any speedo sensor problems. I know if you speed sensor is bad it will cause vtec not to work. R you running a electric speedo or mechanical? Even Mechanical will cause this problem. Other wise you got a loose wire some where. One of the ecu pins could be streched out and not makeing contact at all times just changeing the pin would help. When I use to work in the dealer ship a ghetto rig crx b16 came in. No one would work on it except me I found that their wireing was shitty but not the problem. Turns out the pin was all fucked up and when it was pluged into the ecu it only made contact half of the time. I would check you vtec ecu plug pins. Good luck
 
Originally posted by Projectzc@Apr 2 2004, 07:44 AM
Your not haveing any speedo sensor problems. I know if you speed sensor is bad it will cause vtec not to work. R you running a electric speedo or mechanical? Even Mechanical will cause this problem. Other wise you got a loose wire some where. One of the ecu pins could be streched out and not makeing contact at all times just changeing the pin would help. When I use to work in the dealer ship a ghetto rig crx b16 came in. No one would work on it except me I found that their wireing was shitty but not the problem. Turns out the pin was all fucked up and when it was pluged into the ecu it only made contact half of the time. I would check you vtec ecu plug pins. Good luck

I do have a mechanical speedo,and it loose all the time(the cable is too tight)how can it couse the vtec not to work?
 
Oh easy. Ever throw a speed sensor check engine light?. The computer needs to know that the speed sensor is there and functional. If it is not it will cause the vtec to not engage. Things that will fuck up vtec are low oil, lack of oil pressue, Loss of speed sensor signal, faulty silinoid, bad ground, fauly oil pressure sensor, poor conection to the computer, cloged Vtec silinoid screen, Oh and my fav incorrect valve lash I had a friend do that one lucky he didn't bend a valve. haha I think that covers it.

I will be willing to bet that the reason you vtec does not work is because of your loose speedo cable. Fix that and you will have vtec all the time. If you are haveing problems getting the cable into the tranny rotate the tranny while pushing down on the cable. You put the cable in the tranny and have a friend move the car back and forth just a little. This moves the gear and allows the cable to fall into place. If your cable is really old or bent badly buy a new one from honda.
 
Bingo!
Thanks alot "Projectzc " The problem was in the speedo cable,I would not even thought that this can couse vtec not to work.
Thanks again
 
Originally posted by 90crxb18+Apr 2 2004, 02:32 PM-->
Originally posted by nismo@Apr 2 2004, 12:31 AM
Originally posted by 90crxb18@Apr 1 2004, 07:30 PM
nismo
@Apr 1 2004, 02:21 PM
I had 92 Crx

92?? you sure?

It is an European version,almost the last one was made ;)

learn something new everyday!!

It is possible that the car was build in 91,but was sold for the first time in 92,they do that in Germany,so I would not strongly ensist on 92.But it is one of the last crxes were made for sure ;)
 
Originally posted by Projectzc@Apr 2 2004, 05:02 AM
Oh easy. Ever throw a speed sensor check engine light?. The computer needs to know that the speed sensor is there and functional. If it is not it will cause the vtec to not engage. Things that will fuck up vtec are low oil, lack of oil pressue, Loss of speed sensor signal, faulty silinoid, bad ground, fauly oil pressure sensor, poor conection to the computer, cloged Vtec silinoid screen, Oh and my fav incorrect valve lash I had a friend do that one lucky he didn't bend a valve. haha I think that covers it.

I will be willing to bet that the reason you vtec does not work is because of your loose speedo cable. Fix that and you will have vtec all the time. If you are haveing problems getting the cable into the tranny rotate the tranny while pushing down on the cable. You put the cable in the tranny and have a friend move the car back and forth just a little. This moves the gear and allows the cable to fall into place. If your cable is really old or bent badly buy a new one from honda.

Great Info!
 
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