z28evans

iTrader: (4)

Howdy,
Short version: 1999 LS1, heads cam, rebuilt and swapped into an RX7 (not my first swap).

We were working on the tune (it had been tuned previously and the misfire DTC had been turned off). Using efilive or hptuners - both show a massive misfire on cylinder #1, counts increase like crazy. Spent a great deal of time trying to figure out what was wrong. The other day i unplugged the injector for cylinder #3 and it's misfire count did not increase (but it ran rougher). I did the same thing with cylinder #2, same response. I do not believe it is misfiring on cylinder #1.

So, what can cause an incorrect misfire reading? PCM related, reluctor wheel, or any other ideas? I don't feel right turning off the DTC for misfires, i'd like to fix it right.

Thanks,
James

poconojoe

iTrader: (43)

Does it show a 1336 code for crank relearn?
If it doesn't is that code also turned off?

z28evans

iTrader: (4)

Not showing a code for crank relearn, and i did a CASE relearn using hptuners (not 100% certain it worked). And that code is not turned off.

We actually put a stock tune back onto it to undo some the funkiness from the previous tuner.

poconojoe

iTrader: (43)

I double check to make sure the injector plugs are on the correct injectors.
Drop the starter and pull the crank sendor, go in with a little screw driver and make sure its not loose on the crank.
Use HP tuners to do a single cylinder drop test on each of the cylinders.

z28evans

iTrader: (4)

I swapped the PCM and still shows a singe cylinder missfire, this time cylinder #2 instead #1 (I attribute this to no CASE relearn with the swapped PCM).

I've gone through the injectors - next i'll swap the CKP sensor and see if i can see the reluctor wheel.

Good idea on the cylinder drop test.

Thanks,
James

poconojoe

iTrader: (43)

If the 1336 error DTC is on, it shouldn't be checking for misses
If the code isn't on, it doesn't need a CASE learn.
Start checking wiring, is it a modified factory harness or aftermarket?