Honda D Series Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1 (Edited)
So, I have a 94 civic hatchback and I don't know much about mechanics (This is my first car). I want to know what set up I have and just general information about my engine.
What I know: (correct me if I'm wrong)
- It's swapped by previous owner
- It's a D15b
- Has two vtec solenoids
- P2j-3 head
- P28 ECU

I am having trouble redlining. Vtec kicks in at 4800 rpms, however, when I try to redline it, it starts backfiring at 6000-6500. Why is this?
 

·
They call me Awesome!
Joined
·
4,447 Posts
1) Welcome
2) VTEC should never kick in if you don't have VTEC solenoid.
3) It sounds like you're hitting redline...
4) It really doesn't matter if it's JDM but if the block is stamped "D15B" and not "D15B7” or some other variation of D15B with a number following it, then it might be.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #3
okay, thanks.
I do know for sure that it is vtec. There ARE two vtec solenoids behind the left corner of the head. So if i'm not mistaking, It should be two stage vtec? Or, from what I've read on other forums, maybe even three stage? How can you tell?
 

·
Registered
Joined
·
657 Posts
2 VTEC solenoids = 3-stage vtec.

As far as I know, that engine never entered the US... But it is a sweet engine. If you don't already know, basically Honda made this engine to run as a combo between VTEC-E and regular VTEC. From 0 to ~3500 ish RPMs the head is locked in 8 valve mode. From ~3500 ish RPMs it changes to 16 valve mode. Once it reaches ~5200 ish RPMs it engages the VTEC lobes on the camshaft, increasing lift and duration on the intake valves. I think it's an OBD-2 engine, and the US P28 won't be able to run all 3 stages of VTEC. I may be wrong on that, however. Now, if I am right, it would make sense that you're not able to redline it, as it's probably not using all 16 valves and/or engaging the VTEC camshaft lobes.

I'm not sure what the P28 ECU does when it engages VTEC on the dual solenoid design.. You need to find a way to send a signal to engage the 16-valve mode first, then let the ECU engage the VTEC camshaft lobes.

Do some searching, you may be able to find out what you need to do this. I feel like I remember reading about someone doing some work on their 3 stage vtec engine.
 

·
Registered
Black/Green Civic HB
Joined
·
753 Posts
Needs a different ecu!
The p28 stock will run vtec, but not stage 3 vtec; depending on how the last owner did the swap it could be stuck in 8v mode and that's why it runs/revs weird.

Finding the stock ecu for that engine can be hard, so it probably would be better to chip the p28 and tune for stage 3 ( probably have to make sure the its wired right too)
 

·
B-series Destroyer
4g 4d civic
Joined
·
913 Posts
Maybe your ignition timing is off. I would do a valve adjustment also if you know it hasn't been done recently.
I would find it hard to believe that that is the issue, it's pretty obvious he's running the wrong ecu.
 
1 - 8 of 8 Posts
Top