P30 wiring issue - cant find info anywhere

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93hatchie

New Member
So, I completed a b16a swap into a 93 vx. Had a p28 ecu but just got a p30 and plugged it in. The p28 was showing cel of CYP sensor. The p30 is showing knock sensor and o2 sensor. So, the o2 sensor makes sence to me, that's fine.

The issue is the knock sensor. Car starts and idles fine at first. After driving it for just a min or two, when I come to a stop the idle is rough. Almost sounds like an old v8 with a cam loping. Once this starts to happen, even when the motor is cold, the power at half throttle while accelerating is , weird, it'll go but after the rpms pick up it stops bogging and starts to accelerate harder. At full throttle it just goes with no lag.

The wire that is going to pin D3 was cut by the previous owner. Connecting it up makes no difference. Under the hood however, the wire that is connected to D6 is what's coming off the knock sensor. If D3 and D6 were switched would vtec still kick (right now it is kicking correct at 5500rpms) but throw the ks code at me? If I were to switch these two at the ecu what would the potential harm be?

Any help would be much appreciated. I don't want to switch these and have vtec not work or lose more power.
 
Does your motor have a knock sensor output? It would be above the oil filter towards the drivers' side on the back of the block. If you're block doesn't have it, you can't use the p30. You'll have to chip it or use a chipped p28 with a p30 map with knock disabled, or it will always throw a code.

That said, your idle issues are not because of it. That is probably from the 02 once warmed up. Make sure you're using a 4-wire o2. The 5-wire setup from the vx won't work.
 
Does your motor have a knock sensor output? It would be above the oil filter towards the drivers' side on the back of the block. If you're block doesn't have it, you can't use the p30. You'll have to chip it or use a chipped p28 with a p30 map with knock disabled, or it will always throw a code.

That said, your idle issues are not because of it. That is probably from the 02 once warmed up. Make sure you're using a 4-wire o2. The 5-wire setup from the vx won't work.
 
It does have the knock sensor, that's how I followed the wiring from under the hood to the ecu :p I haven't looked at the o2 sensor yet though although I'm using the one I got with the motor, it was a complete swap that I bought and I didn't even think to look at it honestly. Ill check that when I get to work and update in a few.
 
I had the same prob with my 94 b16 swap... I ran a wire straight from the knock sensor to the harness plug that plugs into ecu
 
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