90 crx si
Obd0 b18b1
Obd0 pr4 ecu

When the tach gets between 3-3500 rpms the engine power surges down. Lights don't dim or anything, I just lose power for a split second. It happens every few seconds when the tach is between 3-3500 rpm like clockwork. It doesn't do it when the tach is in the other ranges (if it does it isn't noticeable) Car idles funny too but it starts and runs fine other than that

Any ideas?

 

Any cels?

 

The check engine light is on but I was told it would be on with this motor swap until I had the ecu chipped? Somethin bout a knock sensor that has nowhere to hook up to?

 

What engine?
Sounds like iming is off, ignition timing

 

B18b1 out of a 95 teg. I converted it to obd0

 

sounds like you have a loose wire, or your IACV isnt working. when you swap the orange and white wire, if one of them isnt making a connection you'll be in limp mode.

IACV not working will give you a two-step type hesitation around 3k rpm. Ive had both of these problems, check your wiring and IACV

 

yea, there's no knock sensor or any bullshit like that.
you can convert the LS motors up and down no problem.
its just adding and taking away sensors.
there's just messed up wiring somewhere

 

can you tell us if you're in limp mode?

what are the codes being thrown?

 

Sweet ill check on my wiring and iacv. Thanks a lot!

If anyone else has other ideas, thoughts, input feel free....

 

Honestly I wouldn't know how to tell if I was in limp mode and I don't have a code reader so I hav no clue what codes are being thrown. Kinda low on cash at the moment so I haven't been able to take it in to have a diagnostic done. Figured this was a good place to start in case it was somethin I could do myself. Up to this point I've done everything to the car myself except the harness conversion and machine work

Whereabouts is the knock sensor or lack of? Is there a way to fix the knock sensor code myself or is it ecu programming?

 

If you try to rev up slowly in neutral and it gets stuck around 3k rpm and fluctuates like a slow two-step, thats IACV.

If you are in limp mode (loose wire), you will not be able to get above 3500 rpms no matter what. IACV you can get past 3000 rpm by applying a little more throttle.

 

I know I can go above 3500 but ill have to check the neutral rev tomorrow

 

It could be a bad distributor too. But you need to get the check engine codes.

 

It's obd0, it doesn't get scanned for codes. Turn the key to the ON position and count the blinks of the red LED on the ECU.

 

All of this talk is non-sense until you read the codes!!! Just stop already... Do as stated above.

 

X2 all these threads on h-t where people want help but they won't even check their codes