so i have a b18c with b16 head. itr intake cam and itr intake manifold on a dc sports header and obd2a to obd1 on a chipped p28. im having problems with my vtec kicking on and shutting off around 7k. also if i also if i speed up slowly as to where i can hear my vtec kick on and just rev slowly it sounds rough as if it stutters. no check engine light and other than that car runs fine. also it does it most of the time but from time to time it just hits vtec no problem.


hoping someone else knows what this is and can help me out! any help would be GREATLY appreciated!!

 

well i sort of had the same problem, and still had good oil
but i ended up still doing a oil change, royal purple, fuel injector cleaner, and with the oil add RESTORE...after that, vtec was screaming for me. check it out.

 

Maybe something loose in the vtec wiring. Check all vtec wiring from engine to ecu. Grounds etc.

 

hrmmm i was thinking of that too! guess my car deserves a nice tune up this weekend. thanks!


any other ideas?

 

because u stated the vtec shuts off...and thats usually due to low oil/bad oil.
royal purple for the win!!!
or if u got more dough, Eneos!!! lol

 

My vtec was running really weak and then i replaced the fuel filter and it was fine so def. replace that as well

 

forgot to tell you, take out the vtec soldnoid and clean the screen out, maybe plugged preventing the flow of oil. Happened to me once awhile back, make sure to use rtv when reinstalling.

 

forgot to tell you, take out the vtec soldnoid and clean the screen out, maybe plugged preventing the flow of oil. Happened to me once awhile back, make sure to use rtv when reinstalling.


What ^ he said

 

bet i will double check all that stuff tomorrow! thanks guys i really appreciate it!

 

ok so i cleaned out the vtec solenoid and re maped my ecu. and still having problems. i've double checked my timing also. tomorrow ill be changing my oil hopefully that gets me somewhere. ill let you guys know whats up tomorrow

 

did you try changing the fuel filter like i said before my symptoms were like the exact same sometimes it was fine and then sometimes it was weak or didn't seem to kick in at all and a new fuel filter fixed it

 

mobil 1 full syn FTW!!

 

royal purple with synerlac and fully synthetic FTW!!!!

 

don't use RTV on that...

Get a new VTEC solenoid gasket, and lube it with oil before installation


Definitely clean that sucker out though. You only will need a new gasket if the gasket is hard.

 

I had a similar problem but mine was due to the oil. Two months later I found a loose wire on the connector going to the solenoid. Weird it had shut the vtec off at 6500 all the time and once i fixed the wiring that pushed out it was fine.

 

haven't got around to doing the filter yet but will do tomorrow. i double checked everything today im not sure whats going on. i changed my oil too.

when i took it out for a test drive vtec kicked in good once in 1st gear but once i shifted as soon as i hit vtec it bogged. no cel no nothing just bogged. as if the ecu thinks its hittin vtec but something is not letting it.

 

Is it too much to ask for for people to use the word "engaged"?
VTEC doesn't "kick in," people.

 

is it too much to ask for advice and not bs? Not trying to be rude but if you have nothing to help this topic than why post something?

Any help with getting my car running right would be Greatly appreciated.

 

Already did, scroll up bud.

Did you clean the solenoid as recommended by others?

 

yup looked clean too. still sprayed it down but no change. i did have a mean oil leak from my cam seal and noticed the plug had oil in it. i cleaned it out and also fixed my cam seal but still no hope. like i said the best so far was vtec "engaged" in first gear once but after that it went back to just sputtering and bogging everytime vtec engages.

 

my fuel filter is fairly new but ill try to get out today and see if that works.

 

What is your VTEC engagement point set for on that chipped ECU?

 

I believe its at 5500. we tested the ecu on a few cars and it works fine. huy at inline racing in houston tested and changed the map on it for a different one but still no help.

Today i changed out the o2 sensor and the vtec worked great for a little while but now im back at square one. it drives good till vtec then it just sttutters and bogs for a bit maybe like 500 rpm and if i keep pushing it it evens out now and goes to red line. but still when vtec engages not smooth at all.

so far i have changed out the following

-oil
-Fuel filter
-o2 sensor
-all the wiring for vtec pressure switch and vtec solenoid
-step down harness
-ecu
-ecu map
-cleaned out the vtec solenoid
-replaced the iacv

I am stumped!!! =(

 

also noticed today that if i drive the car while its cold it works fine with vtec working properly but once it warms up alil then vtec just goes to ****.

also threw on my usdm itr cluster in there today and now everyonce in a while when i drive i throw a cel for vss sensor???

regardless any help would be Greatly Appreciated!!!

 

When the engine is cold, for the first couple minutes VTEC won't engage. Are you sure VTEC was engaging?