I have a lsvtec but its running a ls ecu. If you give more the 30% throttle it bogs down and stays at 3K but if you ease into it goes up in the rpms fine. The map and tps are good so I was wondering if the worng ecu would cause this???

 

Yes change your ECU immediately. Why on earth did you think it would be a good idea to use an LS ECU?

 

 

It came with the car that I just bought

 

And I happend to check the ecu and it says p75

 

The wrong ECU can cause it if some sensor wasn't properly registering due to incorrect pin location. However, in your case, no....the ECU being incorrect isn't causing it. Are you SURE that the TPS and MAP are plugged in properly? Also, check your distributor wiring. I remember there being 2 blue wires...one was slightly lighter blue. Mix those two up, and the TDC won't work properly.

Is there a check engine light on? If so...for what?

Are all the sensors plugged in properly?

Why did you do a LS VTEC but then...have a Non VTEC ECU. You're esentially back to having a non VTEC car again.

 

I think that it is probably already chipped and modified for VTEC. OP does it have a chip where the blue box is:

 

It does not have a chip there. There is nothing there. And again I bought the car for a deal with a jdm front clip

 

Buy a P72 ecu and call it day.

 

Why?

 

Just get your ecu chipped assuming its obd1

 

Because he has an LSVTEC (not sure if it's a GSR head or not), but if it is a gsr he needs it for the secondary runners (I know you know that). Plus running the correct VTEC ecu for the head you are using is the way it should be done. I know the PR4 wired for VTEC will work, but I don't recommend doing it.

 

Any B series OBD1 ECU wired for VTEC or IAB will work fine, provided it was done by someone who knows what they're doing. I've got a socketed p75 and it works great on my GS-R.

OP, I recommend sending your ECU off to Phearable.net or Xenocron.com and having it chipped, socketed, and modded for your needs (provided it's OBD1). Both those guys can also give you a basemap that will let you run more or less safely until you can get a proper tune.

 

I've yet to see a ls vtec run good on a stock ecu.