Ready to start collecting parts for GM ECM in toyota 4runner

[jim_in_dorris]

I know that 1project has done a gm ecm swap on a toyota, so it must be possible. We (my son and I) want to try that on his 4runner now that the new engine is up and running. What GM ECM should we use, and what other parts do we need. It is an 86 22re so it looks kind of like a tpi motor that was cut in half. Will the toyota MAF interface with the GM ECM? Will the GM ECM control the spark timing thru the distrubutor properly?
Lots of questions, but we are ready to start collecting parts and trying to make this work. The 86 toyota ECM is really limited, so this will be a fun project and might make a good how to article.

[EagleMark]

There was a guy who did this about 100 years ago? Don't know if he's still around?

http://home.metrocast.net/~shannen/y...ECM/gmecm.html

I really doubt the toyota MAF could be used, have you looked at that thing? Want to make the Toy run better, do the TPS adjustments and then peel of the cover of the MAF, loosen the screw holding down the spring and twist it till AFR comes in line! Works great!

[jim_in_dorris]

Yeah, we did the tps adjustment a long time ago, it helped a lot, however you can't datalog a toyota. We also will custom tune it for the bigger cam and higher compression with a mild port on the intake side of the heads. If we have to change MAF's, that is ok as long as we can hook everything up. I would really like for it to look stock as much as possible.

[Six_Shooter]

If I'm not mistaken that uses a trap door style MAF, which will not interface with the Delco ECM. As other's have done with this swap, ditch the MAF and go SD.

Which ECM to use depends on what your ultimate goals are, and what you can find.

The '7730/'7749/'7727 style ECMs are popular for ease of tuning and being able to use them in various applications, and they work easily with MPFI set-ups.

To control timing you need to use a GM Ignition Control Module. IIRC, the 22RE dizzy will trigger the GM ICM without issue, just pay attention to the polarity of the trigger from the dizzy to the ICM. This will give the RPM signal to the ECM and allow timing control as well.

[1project2many]

In addition to Six_Shooter's advice, I can offer this:

The 22RE / 22RTE Airflow sensor is unique even in Toyota land. It uses a 9V signal that just doesn't interface nicely with anything. Dump it.

Toyota's CTS curve is the inverse of GM's. Easiest solution is to use the GM sensor. Look at my truck page (link previously posted) as I detail installing this sensor in a later style intake.

Toyota's idle air adjustment device is a mechanical valve that's thermostatically controlled. It's independent of the ecm. If you choose to eliminate it and use an ecm controlled IAC I've detailed an easy solution using a Jeep 4.0L IAC and housing. You will also need to install a thermostat bypass but that's not a challenge.

The '86 intake manifold, idle air valve, and TB was simplified and improved around 89 or 90. You might want to switch.

The Toyota TPS is usable if you choose a P4 ecm with "auto zero" code. The upper and lower voltage provided by the sensor "just fits" the factory settings for min and max. In fact, sometimes my truck would set a TPS low voltage code during cranking when system voltage was low on very cold mornings. The values to trigger the code are adjustable.

The cold start injector can be completely disabled and removed. I used the injector hole for the IAT sensor. I also used the port in the fuel rail as a handy place to install a fuel pressure test port.

Toyota wiring is absoultely nightmarish. I don't have time right now but later I'll post some of the issues you'll need to work with. Things like dual coil fuel pump relays and redundant power and ground circuits really add the the fun.

[EagleMark]

I can verify the distributor will trigger the GM EST, just did one on carb/TBI Toy engine conversion.

For apperance the MAF could be gutted and left there with wiring to no where. Inspections must have lightened up there? They used to be very hard on visual and didn't even care to look at emmissions until that was done.

I know there no data or at least any usable and no way to retune. When my son and I built his 22RE same as your doing and I wanted to do a GM ECM conversion which we know can be dialed in! But with higher compression, .030 over bore, port work and cam we did have this thing run great all the time with TPS adjustments done as per internet writeups with feeler gauges and volt meter. That was the overall fix. Then loosening up the spring on trap door MAF fixed the other fueling issues. It really ran good overall everywhere. His Toyotas off road freinds would come over for a tweak and results were the same every time. IIRC timing was bumped a little but the real timing issue was the dual vacuum diaphram adance cans on distributor... seemed like everyone had a bad thermastatic vacuum valve that never opened or never shut?

Just for kicks someday look at factory service manual for 1985 toyota. It came with carb or EFI. There is 1000 more switches and vacuum lines on the carb! I think I still have it in zipped pdf if you need one...