EJeff8

After digging through my spare tire well today I found old for sale signs. The for sale signs said the car had an engine swap at 94,000. I have it at 121,00. I just simply said WTF. The VIN confirms it as an EX but I have a Y7 with VTEC parts. The VTEC hasn't worked sinced I've had it, but I have the CEL on, so I assumed that was the cause. I have the VTEC solenoid, spark plugs are in the front of the valve cover and I also have a horizontal throttle body. What's going on? Is it a Y7 engine with a Y8 VTEC parts swap? Am I missing something crucial? What have I lost in power and specs from learning it's a Y7 with Y8 VTEC parts? I'm at a loss and need some spec help. Anything that can be decifered for me would be great.

98civdx

Whats the cel code??

D16y7 block with y8 isnt uncomon, and is fine. they pretty much are the same thing minus vtec.

EJeff8

Idle Malfunction and Knock Sensor.

I just read that the wrong ECU combo will mis read the Knock Sensor. It said a p28 ECU will solve the problem because it doesn't read for knock. I just don't have the money for the ECU and a tune up for it.

So I don't lose any engine specs minus the fact that I have a VTEC system they may not be properly installed? I'm fine with that. It seems that they went for the cheaper block, but wanted to keep the VTEC capabilities. So, If I don't lose any specs from the block itself, I'm not worried. I just didn't know what's what. And if I'm not throwing a #21, it's reading VTEC right?

98civdx

Do you have a vaccum leak? how does the car idle?
You likly have no knock sensor at all..

No, you wont loose anything by going with a y7 block instead of a y8,
Ill check on code 21 in a second, but you vtec DOES work?

EJeff8

Instead of compensating for A/C, brakes and such when idling (like it'll increase) it'll decrease to 400-500 and sometimes will dip that low for no cause at all. I cleaned my VTEC solenoid a week ago and forgot to connect a plug, so when I hit 5500, the car died, so I assume the VTEC system is operational, just shut down from the CEL.

98civdx

#21 is vtec spool solenoid valve
#22 is vtec pressure switch, You dont have either correct?

Pull the intake off, while the car is running cover tb with both hands tight so no air is getting passed, if it dies not vac leak, keeps runing you have vac leak.

EJeff8

Correct, so the ECU and wire harness must be correct I'd assume?

98civdx

I would assume yes, because you have a vtec head and your vtec works.

EJeff8

Wow, great way to check for a Vac leak. I've been trying to look for a smoke machine. I'll try that and see what happens. I've also cleaned my IACV and it didn't help.

EJeff8

Now we know it's a VTEC head because the codes aren't on and because of the spark plug position?

EJeff8

The car died when I placed my hand over it, so thank god it's not a vac leak!

EJeff8

So, to get my VTEC running again I need to get rid of the CEL.

Could the Idle just be a case of a spark plug tune up, coolant flush or timing jump? And could I solve the knock sensor by either buying a Y8 sensor or a tuned p28 ECU that will just bypass it all together? These are really the only things I'm concerned with now that I know my engine seems fine and is mechanically sound. When first getting the car, I thought I didn't have VTEC and was going to do the swap anyways. I didn't know the engine terms (such as a Y7/Y8 swap) till this thing reared it's ugly head today. I'm glad it's not uncommon and is basically just a Y8 engine minus the Y8 block. I was afraid I had a bum Civ.