I finished my 3.4 swap (89 4Runner MT, with everything from a 96 3.4 MT 4Runner). Engine starts up great and idles well, but the ignition timing is way too far advanced. It reads 5 degree's ATDC with T1 E1 jumped and 2-3 degree's BTDC without those pins jumped.

I've swapped the crank position sensor and verified the ECM is getting signal from the Cam sensor. I've measured just about every sensor (MAF, TPS, etc). Has anyone experienced this problem? I'm starting to think it's a bad ECM. I ordered another one just to be on the safe side.

 

Further research shows the ECM only uses inputs from the cam position sensor and crank angle sensor before issuing the IGT signals to the ignitor. Therefore, it must be my cam sensor, or the ECM itself that's bad. Or of course, my timing light could be bad too, but I verified it's working right with my 04 Tacoma. The 04 Tacoma shows 18 BTDC on startup. The 89 4Runner shows 2-3 BTDC, so it's way off. I've ordered a new (used) ECM and plan to swap the cam sensor from my Tacoma today, however the freezing weather is not doing my initiative any favors..

 

Sounds like you're headed down the right path, though I highly doubt it's the ECM. Could be a timing belt installed backward or something similarly odd. Is there a CEL and how's it drive?
Also, do you have an OBDII reader? The live data they provide has always helped clue me into what's going on with my 3.4l.

 

It ended up being a problem with my swap harness. My Starter signal wire to the ECM as wired incorrectly. The ECM was receiving a signal that the engine was constantly trying to start, even when it wasn't. Once I fixed that, it ran great.