It's the gears within the motor. They suck. There's a rubber bushing that deteriorates, then you're screwed. A horrible design.

1994 4Runner 3.0 auto with a 1997 3.4 swap. My donor was a rolled 1997 4Runner, so I had all the parts form the same vehicle. I think this helps a lot. Here's my input:

ECM Codes:

Maybe you also need to hook up the power and ground to the OBD2 plug. Does the code reader need these? I kept my plug and had to wire up batt and gnd to it and my code reader (Carchip) works great.

Idle/drivability issues, etc:

One thing I learned with mine was that there are a bunch of power wires to hook up, besides the ECM. The MAF and Ign coils have seperate power wires (not powered by the ECM). When I first fired mine, the MAF wasn't powered and it did run, but poorly.

Fuel pump:

I used the 3.4 pump, was a bolt in. The 3.0 and 3.4 pumps looked identical on the outside, not sure if they flow the same. I do not get any pinging with regular, but I am at 3500 feet altitude.

Power steering:

I wanted to re-use the PS idle up vacuum valve. I cut the pump ends off the hoses and welded the 3.4 one (with the valve) onto the 3.0 hose. Works great.

A/C:

Mine does not work. I used the 3.0 compressor (it is 134a) with the 3.4 pulley. I am NOT geting power to the clutch. Acording to my EWD's, the 3.0 system has 3 wires (A/C, ACT, ACV) between the ECM's and the 3.4 has 2 (ACT, AC1). Maybe the "ACT" wires are the same, but what about the others? One of the 3.4 wires idles up the engine when grounded, but not sure what the other does.

C/C:

I re-used the 3.0 actuator, but I have not figured out a cable yet.

all the pins of the OBD connector are fine. Still can't connect. There's only 4 wires, and all are correct.

I'll check the power of the MAF and Ign coils. I know I haven't done anything with either of these that was "custom", so maybe there's issues here. I'll check them out. Brand new Walbro FP in the truck. Not really any differences, although I've yet to have the stumbling issue since.

C/C works fine now. No issues with this.

Still have yet to work on my A/C. I'm still researching this one.

thanks for the info. I still have not heard from ORS, so I'm pretty much dead in the water on my OBD connectivity.

What did you use for you're C/C? Which actuator? Which cable?

Thanks

I used my 3.0 actuator and cable. As you know, the cable has the ball end, while the 5VZ has the tube style on the TB. I cut off all the plastic stuff off the cable, and I then modified the TB to accept the ball. It works flawlessly, other than I wouldn't want to remove the cable too many times. A picture here is really needed. If you're interested in a pic, I'll upload one.

Please and Thanks.

I was going to try and figure out another cable, but now think I should just use the ball one.

Hey wellyman.....have you worked your problems out? Ever figre out what the high idle and stumbling thing was?

How well does your cruise control work? Mine works fine, but when I first turn it on, I gotta hold the button in for a minute for it to "catch up"...so to speak. Once the it engages the thing works fine. My C/C cable isn't very straight....I think the way I've routed it is giving too much resistance and it takes a lot of vacumm to suck in the slack.

Scratch that Welly, I did it. Works great.

CO, mine works fine, but it's an electric system (not vacuum). I had to loop my cable because it is so long, but it's not a problem. Could be your cable or check you're vacuum source.

I was just out there looking at it....I think I had the vacuum resevervoir plummed wrong. Seems to work much better now.

I have yet to mess with my A/C, so that's still on my list. I have pretty much given up on the scanner/ECU thing. It just won't connect. I don't get it. I KNOW I've got all the power/signal wires hooked up right, and all connected. There's no loose connections or broken wires. The ECU simply won't communicate. I returned the scanner yesterday, as I've given up on it. Still no call back from ORS. Don't know what else I can do or try. My idle is fine, most of the time. Sometimes, it falls to a very low idle, around 400. Never has died, but it does fall too low when at stoplights sometimes. Most of the time, it's at 900-1000. I really want to verify my charcoal canister hosing, as I've yet to find any good pics that show the routing and hookups. I'm still wondering if I have them hooked up right. If any of you have a closeup, clear pic of how to hook them up, I'd appreciate it. I know they're different per year, but I can't say I'm 100% sure I have it right. My CC works flawlessly. I would have to say that my biggest issue is that I suspect pinging under load. I don't know if its pinging for sure, or if maybe it's noisy injectors. I'm not too good at this type of diagnosing. Under heavy load, I hear it clearly. Once at cruising speed, I hear nothing. My MIL is NOT lit, and I know the motor has 2 knock sensors, which I would hope would throw the MIL if knocking was detected. So, since I can't connect to the ecu with a scanner, I'm kinda assuming/hoping that the lack of the MIL is a good sign that all is good. Just don't know, and don't know what else I can do/try at this point. Got stuck again with it last weekend. Got out of the truck and had my spinning front wheel off the ground. Frustrating having a 4wd, or really a 2wd truck and getting stuck. Looking into the EZ locker for the rear and one for the front.....Never ends....