Ok I will try to explain this as short as possible.

I bought a kg built Gsr from a friend. The engine ran perfect and Vtec worked fine. I have a 97 hatch that had a y8 swap, it ran and Vtec worked fine.. the car is a cx and I used a ex harness.


I installed the engine and now when Vtec pops it hits a wall, sounds like some sort of ignition cut. The head is built with oversized valves cnc ported, springs ect. It has skunk2 pro 3 turbo cams. Vtec pressure switch is disabled, ( even tho oil pressure is fine) I have changed the sel. with one off a running engine. I have also changed the dizzy, checked the continuity in the wire... has good connection. Timing is dead on ect. The car runs fine on low cam and if I in plug the Vtec sel. it runs like ***......

I would like some help with this guy so please post any and all ideas.

Thanks.

 

I can't even understand you!

 

Sorry. Ment to say if its plugged in it hits a wall right when Vtec is suppose to pop. If its unplugged it runs fine on low cam.



If u can't understand sorry.

 

what ecu are you running? is it tuned?

 

Ideas to try:

a) fuel - is it possible the fuel pump/filter can't deliver enough?
b) electrical - with the new wiring harness, possibly a ground problem?
c) cam timing - any chance it slipped a tooth (etc) during install?

I'm sure you'll figure it out! Sounds like a nice engine.

Mark

 

Chipped p28
Yes on chrome gold, and the guy that tuned in my buddies car is the same guy that tuned it in mine. This guy knows his stuff and is a very respected tuner. He also has never heard of this problem. Errrrrr

A. I changed it like a year ago....the thing is that it runs fine to 10000 on low cam
B. I am using the same one I used on my supercharged y8 and I has added a extra ground strap...
C. I have checked it time after time and its dead on.

These are 3 good points... thanks.


Would not having the cams degreed cause this? Also when I have the Vtec sel. unplugged and have a test light hooked up, and I rev it up. The light comes on and is bright. If I have the sel. Plugged in and the test light hooked up when Vtec pops the light is dim like it has a really bad draw it the system. I just don't know. This is very frustrating. :-(


Also I don't know if this would matter at all, but I am running FIC 1350CC Fuel injectors

 

Ok, how about this... either short in vtec solenoid, or wire, and it's drawing too much current and dropping voltage. When voltage drops, fuel pressure drops along with (possibly) spark voltage? Wonder if it could cause short pulses on the injectors too (delayed open, shorter 'on time', etc)?

Now, alternative to short is poor ground - i.e. it would have similar effects (low voltage) but without the excess current draw. Forget either of the chassis to MT or Engine ground straps?

Got a spare vtec solenoid handy?
Put a voltmeter on the system and tell us what happens when vtec hits? Be sure and check directly across the battery, but also at the vtec sol itself and whatever ground it's using..

Thx - Mark
-

 

K I will do that ASAP. I have the cams out right this sec cause I am gonna throw in some stock ones and see if that does anything. But I will post my findings on that when I get a chance. Thanks mark

 

Just a couple of pics

 

really nice!

 

indeed nice, yes i would have to agree it sounds electrical

 

Thanks guys. And ya, I am looking for a harness. My only problem is that my previous engine ran fine and Vtec worked great.

 

Bump still doing it

 

Adj valve lash, changed harness and Vtec sel, have great oil pressure, and still no Vtec. I can't believe none else has had this problem. Someone please help.

 

Try another ECU!

 

Were you able to take voltage measurements mentioned earlier?

Also, in a different recent thread someone had an IAC acting up that seemed to create similar issues to yours - he didn't know if it was IAC or some kind of stuck valve in the EVAP canister. You might block 'em off for a quick test and see how it behaves at VTEC?

Change one thing at a time.. ; ' )

 

10000rpm is up there. Car looks clean.

 

One step ahead of ya. Did that, and it didn't help.

 

Yep voltage is great.... I do have another iacv, so I will for sure try that. Evap is already gone.
I also have done a lot of reading on theses skunk2 pro 3's and people having issues. So I am changing back to stock cams tomorrow, and see what happens. Thanks for the help

 

Well guys I figured it out. Woohoo. Took the skunk2 pro 3's out and put in some stock ones. Boom now I just need to get the pro 3's and the cam gears degreed and I can run them. Thanks for input people

 

You were running pro 3's at 0'0?

 

Yes sir not good?

 

even pro1's need to be degreed properly....i'm scared to see what else is done on this car

 

The thing I don't understand is according to your OP the motor ran fine in your buddies car. How does it not work after you swapped chassis? Are you sure it was even running good when your buddy had it?

 

Wow thAnks man, I got this engine already built and it ran just fine in my buddies car. Thanks for the low blow!