I don't understand how you take logs with tunerstudio freezing, are you running VEAL when it locks up?

I expect DIY's cable will fix the freezing issue, because I have a similar one occasionally with the prolific adapter. To get the tune mismatch dialog you must be running VEAL when the laptop looses connection, and if you're doing that it will write to the ECU occasionally causing lost sync hits that feel a lot like a misfire...

I think you have more than one problem, maybe? Try changing the write to ecu checkbox in tunerstudio if you are going to run VEAL.

If you aren't running VEAL, can you make sense of any of the numbers in the tune compare dialog? It's not corrupt gibberish is it?

 

It does not give me the miss match dialogue withe the data logs, it just goes off line.

It does give me the miss match dialogue when running VEAL.

i do have the write to ecu box checked currently however i have also tried it with the box un-checked and it did the same thing.

I just purchased the USB adapter from DIY and it should be here soon.

 

Today as I expected, the Misfire has returned. It definatly seems to be computer related.

All the wires and connectors that are related to ignition coils have been checked, "i hooked up an ohm meter and put a paper clip in the connector that goes on the coil for the trigger wire, and also the connector that comes out of the ecu." vigorously wiggled the connections and the wires and no jump in the ohm meter at all.

Also checked them for dc voltage and preformed the same tests.

Iv also checked the power wires in a similar way, even added an extra positive and extra grounds.

I have tried 8 OEM ls2 Truck coils, "surely not all of them can be bad"

I have tried 4 OEM toyota coil on plug coils

I have tried 4 aftermarket toyota coil on plugs

I have also tried 4 factory coils since i had another engine in my garage to borrow them off of.

there is no way that 20 ignition coils going through wires that have been checked numerous times and have not been modified are bad.

"i have not modified the wires from factory chassis harness connector all the way back to the ecu, only modifications have been to the wires going directly to the coils from stock connector."

DIY-Autotune usb to serial adapter should be here tomorrow as well as Matt's book on tuning I thought I would buy the book because the reviews on it are really good and there is much more to know about efi and tuning than I currently know.

 

In case anyone was wondering, after trying EVERYTHING for 2 weeks,I finally broke down and bought another set of coils, and voila... the problem was fixed. The original set was a set of claimed "OEM" AC Delco coils off eBay for $139.99. I figured there's no way a brand new set of OEM coils could be bad. So I'm guessing they were either knock-off AC Delco coils, or they are legit OEM replacements that are just lower quality than the ones that actually come on the trucks, which do look slightly different. The ones I bought are from O'Reilly and are called "Borg Warner." Still running strong.

 

Two questions, how did you wire up your tach to work with those coils?

Next is the capacitors for the trigger wire, do they go from the trigger wire to a ground or do they get spliced into the trigger wire?

I may try to filter out some noise because my data log said my max rpm was 38,188 rpm and that is not right.

I got diy's cable and it works and tuner studio doesn't seem to go offline now.

 

To preface my car is a 1.6L running MS2PnP, it will likely be different for other setups. For the tach I spliced the Yellow/blue and black/white of the igniter harness together with the tachout signal from my MS2. I did the resistor from IG- to B+ in the diag box but I'm not sure if it was necessary, some people say they don't need it. Then just turn the "tacho output" on in MS and selsect whichever pin you used for your techout signal. From what I read you need the capacitor between the 12v source and the ground, I have not heard of adding it to the triggers.