So let me begin by adding that I have tried probably everything in the book to get my ls/vtec to work in my 1992 GSR but have become unsuccessful everytime and need as much info about what could be wrong for it to work. This has been going on for quite awhile now and with school and work I just don't have all the time in the world to tear the motor apart and start over and what not.

So first let me tell you what I have done and or changed

I have jumped the pressure switch and changed it to see if that was the problem
I have put my vtec solenoid on my friends car and it worked
I have put my motor in my integra that was first in my crx thinking it was a wiring issue but used the b17 stock wiring harness and still no vtec
I have already replaced the dizzy once by Distributor King
I have a tach reading
I do have oil pressure but it only goes to 50psi on full throttle (maybe not enough pressure)????
I have a chipped ecu from Eric's Racing (have used another ecu when it was in the crx but it had no tach reading and was a custom wiring harness)
I have comp cams with 3 lobes, would have felt stupid if they were only 2

If any of you have any input at all that would be great. I am getting it tuned next week and if I can't get it to work I will just have it tuned for just a high compression ls which would suck but I need a car for school. Thanks and happy findings

 

so what is the problem not getting vtec??? WHat is the chassis...... what car year and model and what ecu are you running... thanks some more details and we will get u all fixed up in no time!

 

yep vtec is not engaging. 1992 Acura Integra GSR. the vtec in the b17 worked fine. Running a p28 ecu. The vtec never worked even when it was in the 1991 CRX hf

 

The problem might have to do with the speed sensor. The cable tranny might be using a speedometer cable and the P28 requires a VSS signal from a sensor like those found on the hydro trannies. Simply put, a P28 won't switch onto the big cam lobe without a proper VSS reading.

 

well if i try the ecu out off my b17 would that possibly discover the issue?

 

kendall friend had same problem in a ef

 

so what ecu do most guys run in an obd1 and obd0?

 

still looking for more answers.......thanks

 

i use a p72 chipped for my eg obd1 worked fine then friend use p28 chipped for his crx both chipped by chorme is your wiring even wired up right?

 

I think some (if not most) of the tuning software for modified OEM ECU's has the ability to bypass the VSS signal when making the transition to VTEC. I'll have to look into it again, I haven't played with any of that software in three and a half years now.

 

Yeah all the wiring is completely stock from my b17.

 

There is a guy here where I live that was going to burn me a chip to fix my air/fuel so i'm not running so rich. So if you find the answer he could jump that vss?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Youlose1305 &raquo;</TD></TR><TR><TD CLASS="quote">

I do have oil pressure but it only goes to 50psi on full throttle (maybe not enough pressure)????
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IIRC, I believe the required amount of oil pressure for Vtec engagement is 70-80psi. I say that because that's why people swap out the LS oil pump when doing a Ls/vtec build. The LS oil pump is not capable of flowing enough adequate oil to the head like the B16/GSR/ITR.

Possibly something screwy with your oil pump? Maybe an air bubble in the Vtec solenoid? Have you tried to bleed the solenoid?

 

I actually just changed the hose running from my block to my head from a 3/8 to a 1/4 and it has significantly brought my oil pressure. But still no vtec

 

in my b16a obd1 i used a chipped p28 ecu

 

i had a b20 with a stock oil pump that made vtec work.swapping the oil pump is not neccesarry though reccomeded. who built the motor?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Kendall &raquo;</TD></TR><TR><TD CLASS="quote">I think some (if not most) of the tuning software for modified OEM ECU's has the ability to bypass the VSS signal when making the transition to VTEC. I'll have to look into it again, I haven't played with any of that software in three and a half years now.</TD></TR></TABLE>

OP,

I agree with Kendall in that its most likely an ECU issue if you have addressed and verfied that all other possible varibles are working and not causing the issue.

If your getting it tuned then ask your tuner if the software his using (probably CROME, ECTUNE, or what ever your choice) allows you to turn off the VSS function which may be keeping your VTEC from working. Perhaps this was overlooked when it was originally programmed.

I didnt want to deal with any ECU compadibility issues with my LS/V, so I just bought a chipped/socketed ECU that already had a base ROM programmed with CROME.It had alot of the govening features disabled + the A/F programming was based on a dyno'd LS/Vtec that closely matched my build as a supplement to tide me over until I could get the motor dyno tuned.

 

I might be your oil pressure because my Teg reads 80-100 psi. It does have the B18A1 head on it but just try it it might work, not making any promises though peace

 

Hey thanks guys for all the help. Well I built the motor and yes I think I have covered most issues that would cause no engagement into vtec so I keep everyone posted on how the tune goes and what not......

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by one bad dx &raquo;</TD></TR><TR><TD CLASS="quote">


IIRC, I believe the required amount of oil pressure for Vtec engagement is 70-80psi. I say that because that's why people swap out the LS oil pump when doing a Ls/vtec build. The LS oil pump is not capable of flowing enough adequate oil to the head like the B16/GSR/ITR.

Possibly something screwy with your oil pump? Maybe an air bubble in the Vtec solenoid? Have you tried to bleed the solenoid?
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the older pumps were slightly different but not by much, all 96 and newer B series oil pumps are the exact same thing fyi


i would bring it to a knowlegable shop and let them take a look at it as it seems its beyond your knowledge

 

Well got my car tuned and did the bypass of the vss and still NO vtec, I almost want to cry but at least my car will run good in the mean time of scratching my head. I think later on this fall I am gonna take the head apart and double check all my stuff. My friends and I are baffled to the fact that this $2500 head is acting this way but it may come up to be something we never would have thought of..........any other ideas would be great. Thanks