cut. i go into hondata and turn the vtec off and it will rev all the way to redline no problem but without vtec. it doesnt make sense to me or anyone else. if vtec was malfunctioning or not working lets say because of oil pressure or anything else then it would still rev to redline, but just without vtec working...

i did some datalogs of when this happens and i dont see anything at all in the logs indicating why this is happening. the logs dont even say there was a fuel or ignition cut coming on. but thats exactly what it feels like.

i really am stumped right now and never seen anything like this before. he even took it to a respectable tuner here in missouri and he didnt know what was wrong either. i dont think its anything mechanical at all. if anyone has any clues what the problem might be please help me. thanks!

 

Sorry...but based on your description I have no idea what you are talking about. Try to explain a little more clearly and post yours logs and calibration.

 

yea im lost too.

 

a friend of mine had a similar problem to this, turns out the pin @ the ecu had a bad connection. after we spent all day trying different **** to solve the issue

why dont you try enguaging vtec with a wire straight to the battery and then try to rev up your junk.

 

ok, you know the boost cut feature in s300 and when you overboost what it feels like when it shuts the engine off?

....

well as soon as vtec comes on at 5200 rpms thats exactly what happens...if i turn vtec off, it revs to redline no problem.....but without vtec, which is no good lol.

ill have to get save some logs..

hmm ill check it out.

 

Instead of wiring vtec directly to the battery, use one of Hondata's output and run it to a relay for vtec to bypass the ecu/factory wiring.

 

but lets say it is wiring....that just means vtec wouldnt work right? and it would still run to redline and not shut off at 5200 rpms...just like it does when i turn vtec off in hondata.

 

i had a issue just like this and the reason why it was happening for me is because vtec was set at 5200 and the lowest rpm scale on my highcam map was like 6000 or something like that.
so basically the ecu had no information to send to the motor at 5200 rpm and vtec engaged.
so check to make sure that your high cam goes as low as 5200 rpm in the map.

 

that makes sense but his high cam map starts at about 4000

 

anyone else have any insight?

 

I had an issue like that a few years ago and turned out the rockers in the head were installed incorrectly. On the dyno when I would hit vtec I would lose 90whp. Without vtec active it would rev to redline without issues. Hope this helps

 

I had this problem too last year.

 

and what did you figure out?

 

Seen it happen on a car with a dented oil pan the pan being dented restricted the oil around the sump (dented the sump too) not having enough oil pressure to activate the VTEC function. Just another random thing that happened before

 

its not the oil pan, it has oil pressure. ive seen alot of oil pans dented into the pickup... the oil light will come on and the bearings will go out soon after..

 

bump i guess....i dont think anyone is gonna be able to figure this one out..

 

it's better to take it to someone that can help, cuz by writing over no one will get ur point right

 

what? lol we did take it to someone. they didnt know what the problem was.

 

figured it would not be curable..

 

Did you try activating VTEC at various points?

Try way too low....3800

Try about normal....5200

Try High....7200

And does it only cut EXACTLY as you hit VTEC?

 

no i didnt try other points..

yes EXACTLY when vtec is triggered on...seen it in the datalog. datalog didnt show any kind of fuel or ignition cut become active when vtec was hit but as sson as vtec hit on the log everything went dead on the graph like it was a iginiton/fuel cut.

 

have you tried a different ecu? sounds like the ecu might be resetting. do you have an MSD box in the car? maybe the ecu is resetting due to noise/interference/feedback?

i have a similar issue i'm trying to solve but instead of vtec, its the EBC solenoid. as soon as ebc is activated, the ecu resets. have not had time/money to try new ecu yet though.

 

try this, and make a LOG of each run...

if it still happens at EACH point...post up your three logs and the calibration.

 

Timmy,

Sounds like you might have something hooked up (wiring) wrong. Or the PWM components in your ECU were installed wrong causing some sort of voltage to be put back into the ECU causing it to reset.

 

screen shot please.....