LT-8 timing setup problems
 

I've never messed with a Microtech before and this is proving to be fitful. :) Trying to zero the timing on an FC. I've searched and read a bunch of the threads on the subject. I'm am in the Zero-R camp on marking the pulley at TDC and locking the timing at 0*.

Here is where the problems begin. First problem is the timing won't lock. With the lock enabled I'm seeing around 20* advance on the pulley and the the timing flutters badly. The ECU is programmed for around 20* at idle when unlocked and even though the gauge display on the laptop is showing 0* I don't believe the ECU is locking the timing at all. There is no change in the sound of the engine when the timing lock is turned on and off like there should be. I've done enough Haltechs to have a real good idea of what I'm doing here and the it just doesn't respond like the timing is being locked at 0*.

So at that point I'm just assuming it's not going to lock the timing at 0* and I figured I take another tact at zeroing the CAS. I changed the base timing map to 20* at the load points around which the engine was idling. Basically locking the timing at 20*. It will sit and idle all day with the gauge display on the laptop showing 20*. So I should see 20* on the pulley right? Well, I marked the pulley at 20* and I'm real close. The problem is that the timing mark flutters quite a bit. As much as 5* +/- around the 20* mark even though the display on the laptop never varies off 20*. Not close enough to inspire confidence in beginning to tune.

First question is why won't this thing lock timing at 0*? Second question is why would the timing vary when the ECU is reporting that it's in a steady state?

Two days and no one wants to comment? I need to get this thing accurately zeroed.

So when you turn the CAS with the timing lock on you can't even get it close to 0*?

No. Let's say I fire the car up as it sits with the timing lock turned off. Shoot it with a timing light and I'm seeing around 20* timing. The idle is set high right now because I haven't even attempted to tune anything. So the ECU is saying 18-20* and that's about what I'm seeing on the pulley. So now we go to lock the timing at 0*. Engage the lock. Readout on the laptop says 0* however the timing mark hasn't moved and there is no audible change in the engine note. The timing isn't locking. I can move the CAS and that does change the timing. However it's not locking so I have no reference point to even have a clue where to set the CAS.

Bottom line is that the timing lock feature isn't working.

Do you know if the MT is set up for a 13bt or a 13brew? I have read your post and it seems you know what you are doing. Another thing, have you re-stabbed the CAS?.
Another way to help you most is talk to MT or email them on there website. Ther is a posibility that there is a problem with the unit itself?. Good luck and keep us updated.

Thanks for the input. I got it to lock. It's possible I might have thought switching it to program mode was the trigger to lock it and not actually engaged the lock after entering program mode. It's now zeroes as good as possible. The timing still wavers a bit. The ECU keeps throwing a random RPM error. The install (someone else's) is not the cleanest and it's certainly a noise issue with the unshielded trigger loom. I'm certain taking care of that issue should resolve all problems.