weekendboost

I swapped the z6 over to an ej1 to replace my engine. The engine was working perfectly fine when it came out of my si hatch, no cel.
I've checked coolant, oil, cluster, and ecu and I can't seem to figure out what the problem is. I'm suspecting it's a sensor but I'm not too sure.

mk378

Is it supposed to? All the ECUs have a rev limiter function.

You also have to consider tach calibration. The stock dash tach is rather approximate. It can be adjusted with a potentiometer on the circuit board.

weekendboost

The redline on the z6 is 7200 and it was perfectly fine when I had it on the hatch. I've never tampered with the circuit board so I doubt it should be any different.

TomCat39

Do you get the same results in every gear or are you basing this soley off of 1st gear bouncing off the rev limiter?

weekendboost

1st, 2nd, and 3rd.

TomCat39

You might want to verify with an external tachometer. You can put the front up on jack stands so you can have it in first and have someone rev limit it while you check with a laser tach.

I suspect your dash tach is off like previous poster mentioned.

weekendboost

The reason I don't think it's the tach is because I have 2 tachs, 1 from my hatch and the one that has the z6 which is the ej1. It has always revved to 7200 on the hatch, when I moved it over, I started it and test drove it and it didn't go past 6500, so I swapped both the p28 and the cluster over and it's the same.

testify

It's an OEM ECU?

What happens at 6200? Rev limiter?

weekendboost

oem p28 both manual unopened untouched,and once it gets to 6500 it sounds like a rev limiter. No bogging or any cel.

TomCat39

As far as I understand the distributor's CKP (CranK Position Sensor based off the Cam Position) tells the ECU the engine speed, then the ECU tells the Tach.

You've swappedd everything else.... Did you keep the same Distributor with the motor?

weekendboost

Yeah I read that somewhere on HT. It was never touched though and timing is good too. I just got my hands on another distributor same part number, I'll swap it the next day and update.

weekendboost

Late update, ignition coil ended up being dead on the replacement so I ended up swapping the ignition coil from the old one. No difference though.

weekendboost

Any suggestions? After some more searching it seems that most people haven't found a solution who have similar problem as me.

TomCat39

You never reported if you have verified your findings with an external tachometer.

weekendboost

I'm waiting on my laser tach to be shipped. I'm almost certain it isn't the issue mainly because both of my clusters are reading the same plus one of them was working perfectly fine before on a different car. This is literally the only thing I haven't checked so I'm going to test it in a few days and if it doesn't work I'll just give up. I have no other idea on how to solve this and no other suggestions, it maybe be something deeper that requires me to open up the whole engine.