LAMBO-LS

I have a problem that when VTEC opens at any RPM it will fall on its face and make almost no extra power like it should.

I have a Port and Polished B-16, built with tit dual springs, tit retains, valves, and now ITR cams

Its a stock B-18b bottom end

550cc injectors with skunk2 fuel rail

Its boosting 10lbs with a short ram mani

Also stock MAP sensore

chrome is EMS

No matter what we have done with engaging VTEC (manualy at all rpms) it makes less power when open! And the duty cycle for the injectors is almost off, and still running to RICH. HAVE NEVER SEEN THIS BEFORE NONE OF US!

My tuner has never seen anything like this what so ever and we can not figure it out, previously i had bigger more aggressive cams (BLOX B'S and vtec wouldnt even open)(then went to skunk2 tuner stg 2's and this prob happend) in it and thats what we thought it was, but now i have stock ITR's and it is still messing up......if you got any good ideas let me know please for we have been dealing with this for like almost 2 weeks now and i dont want to have to take the head off and change it for something else (thats what we think it is now)

92redhatch

i had this problem. when i would go into vtec i would lose like 90whp. it turned out the pins that lock the rocker assembly were missing or not installed correctly. check out your rocker assembly.

LAMBO-LS

ya i am losing horsepower but not that dramaticly, i just called them and they had just took valve cover off to make sure everything was spaced correctly and what not, so everything is installed correctly..... were thinking it is to much back pressure cuz i am running a real short mani......im really hoping we can figure it out and that its not the head it self.... Thanks you though for the idea bro i appreciate anything thrown my way....

Turbo-LS

iTrader: (4)

its not the manifold, if yoru running a miniram they flow very well with the short runners unless its garbage and has a terrible collector. what size exhaust are you running? what turbo, what size dp ? are you running a catalytic converter ir so new used how old if used

i had a newer cat on my car with the exhaust unhooked when i put in my new rebuilt engine. got some debris in it when i drop to my buddys shop to redo my exhaust and once hooke dup when i hit vtec it fell on its face cause the cat was clogged. hollowed that **** out and it was good to go.

jnv255

I melted a Cat. and it did the same thing.. 100$ it's the cat converter

LAMBO-LS

I am running a 3" exhaust and down pipe, no catalytic converter (well at least i am pretty sure it is hollowed out, never taken off to check for myself, dumb not to).....o and turbo size....uhhh man t3/t4 ebay dont know the trim or exhaust side.......... ill hit them up in a min and tell them to look to make sure, but almost positive that it is hollowed..


this other guy is saying its the cat too.....im going to call them rite now and see just to make sure!!!!!

dc2lsv

i would try bigger injectors. my buddys h boosted was doing the same thing. by the time vtak would kick in, injectors were maxed out. i think we out 750s , retune, and was perfect.

LAMBO-LS

if its a the cat ill give you a hundered JNV255 !!! lol

Nah bro its not the injectors i dont think you read my post rite, IT IS TO RICH!! the duty cycle on the injectors are at like 10% and still to rich......no where near maxed out...

jnv255

like i said, when mine melted, it did the exact thing ur talking about. As soon as it hit Vtak it Bogged and would go slower than when it was out of Vtec... Its a good place to start, it dosent cost anything.

LAMBO-LS

ya word it is a good idea i can just take it off....i tried to call them back and they were already gone so they'll just have to try it tom.....but ill let you know how it turns out.....b/c like i said im pretty sure it is hollowed out, at least that is what i was told....stupid for not checking myself though...

got a question though, if i buy a high flow cat, will it help with emisions if i have to get it done? And how much do you think it will hinder with power?.....

Turbo-LS

iTrader: (4)

Have you at least tried swapping out ecu's ??

cjordan

iTrader: (1)

i was kinda thinking the same thing...

SIXTY-1HATCH

MAKE sure you have gone over everything basic first!!! Check all rocker pins, and that everything is good on the head. Make sure vtec solenoid is working, make sure the little screen on it's not clogged. Timing is on right @ cam gears, and distributor. I had a similar problem when i put stg 2's in my gsr and it wound up being not enough fuel. What are you tuning with, and are you using a wideband.

You say your on your STOCK map sensor. What are you running for boost control, and what size spring is in the gate?

Anyone I know that ran a stock map sensor, had to use/order the inline pro check valve, it's a little bleeder cuz that sensor aint doing **** over 8-10psi MAX!!! You need to order a motorola or something ASAP!!!

LAMBO-LS

Turbo-ls---as for ECU's mine is chiped but while on the dyno i run off of the tuners computer, but i am running crome, its not a ECU problem for sure....

Sixty hatch----We have checked everything twice when it comes to rocker pins, vtec IS working, timing is on checked it everytime b4 putting on dyno...ya i am running stock map but not going over 10lbs...i believe it is a 8 or 10lbs spring thats whats reading on the computer....

Well found out today that i DO have a CAT and we punched it out and rebolted everything back up, i am 98% positive that this is the problem for it falling on its face with back pressure...JNV255 i think i owe you a hundo!!! lol...but its going back on dyno tom to see if that is the problem....but i am pretty sure that is it..... ill come back on tom and let ya'll know if that was it or not....even post some numbers if everything goes well......lets hope my baby has been in shop off and on for like a month now trying to get **** fixed!!!!! But thanks for the ideas....if its not that then im going to start all over on the head and tear it down and re-do it!!! Thanks again everyone....

B16Drag

PM for the paypal account!

jnv255

if that was the problem, glad i could help.

LAMBO-LS

So they punched it out and put it on dyno today and boost sooner but still falls on face when VTEC opens!!!!

Going to try and mess with it more tom but do not know what it could be, as of now we are only boosting 8lbs just to try and get vtec to actually "crack".....so lost on what to do next.....we both think its the actual head itself, like a bad port job.....he has even called skunk and other people that he knows that have been in the business for a while.....

if anybody got any other ideas im down to hear him....looks like a no go with the HUNDO JVN255

jnv255

Damn that sucks.. Oh well that's what it was when mine did it, GL...

LAMBO-LS

so sorry for the WAT late up date....it ended up being the coupler that connects to the turbo!!! it had a rip where the clamp was at and you could not see it unless you took it apart!! and thats how we found it!!

numbers-275whp 190somthing WTQ

the only thing that sucks is that i dont have enough RPM the Graph climbs all the way and keeps pulling to 7500!!!


looks like i gotta build the bottom end now! haha