For a friend, who just finished his S->VTEC swap:

I just replaced both the vtec solenoid, and the pressure switch (not cheap). The car is not throwing any trouble codes, and I think vtec is working now. BUT in higher rpm's the power is cutting out(but I think I can hear the vtec).
I know my vaccum lines still are not hooked up right, sooo I'm wondering if I could have damaged my MAP sensor. I have read that this controls the air and fuel, and other functions. It feels like the fuel could be cutting out on me.

Also my tach is all over the place. When the car is at idle, you can see the needle bouncing, and when you rev the motor, it jumps all over the place. I set the timing, and it is right as far as I know. 15 degrees BTDC? The distributor is new (rebuilt) so there shouldnt be any problems there. Unless since it is a USDM distributor on a JDM motor, something wont work right. But the only difference is JDM uses an internal coil, and USDM uses an external coil.(I cant see a problem here)

Sorry for the long post, but the more info the better ,right.


Jeff, who is about to burn his car!
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Thanks for the input guys

 

did your run the little pink wire to the bypass valve in the intake manifold? becuase if you didnt those valves are not opening up and that can really kill your top end.. (for some reason all the write ups i have read dont mention this) the S doesnt have the bypass valve so you have to run the wire

 

Can you show where it goes? I was there last weekend and we were talking about the air intake bypass valve, and the PINK WIRE!

There was a plug from the S that plugged right in near the IAB but we thought that wasn't right...we couldn't figure out where it goes

Here's a pic borrowed from Gude:


where does the plug go?


[Modified by satan_srv, 3:27 PM 9/19/2002]

 

i will get my digital camera and walk out there right now to see if i can get a picture of it

 

well i couldnt get a picture of it and im looking in my book now to see if i can find it.. the last time i saw it is when the engine was out.. it should go to the intake air bypass control solenoid valve shown as #12, i remember it was pink, im going to see what i can find and call my friend that helped me to see if he remembers any more about it

 

Wow I have been messing with this exact problem for about 6 months since i did the swap. I had an extra plug after everything was done, damnit it's that one. It's a 2 pin round plug pink wire and a black. I gotta hit the garage tommorow and hook it up. So you guys are saying it plugs into the little plastic black box under the manifold where the vacume lines are for the secondaries? I have been trying a few things with the secondaries lately because i thought i was having problems. This may explain it. I also heard if you take the vacume line off the mechanical part that acctully moves the secondaires it would leave them in an always open state, is that true? Thanks for any info

 

I just called him, I think it's his gas. He couldn't remember what he put in last, but I bet all my money he stillhas 87 in his tank.

He likely still has 87 in the car from the S days. The knock sensor is sensing the knock and retarding the timing and dumping fuel, which is why he's getting power loss. I told him to put in some octane booster for now, and get Ultra 94 from now on. JDM compression is 10.6:1 and needs higher octane than a USDM prelude.

Just one of those things you never think about when you're doing the swap I guess.


[Modified by satan_srv, 10:55 PM 9/19/2002]

 

Did he tell you that that fixed his tach from jumping? Cause mine does the exact same thing. But I just pulled the engine today, so I really hope it wasnt just bad gas.

 

no the bad gas was in reference to the power loss up top. He can't seem to figure out the tach thing, cause the engine isn't surging yet the tach is. Maybe a voltage thing? I have no clue.

 

Oh, then it's probabaly just a short or a ground out somewhere. My car surges, misses, backfires, dies, etc. When my tach goes crazy.