joesscamaro

Got an '86 4Runner...22rE, manual transmission, non-turbo. It's not been running for a while, and I'm going to try a different/used ECM. I found one that came of an '88 Toyota truck. I know I have to see what engine was in the truck and if it was a manual trans....but if all the specs were identical, would this '88 ECM work in my '86? I thought it would be compatible, but the lady at the shop told me that only '86 and '87 were compatible. Is this true? It had the same number of prongs for each plug on the ECM...so I'm still thinking it would work. Any advice?

abecedarian

88 may or may not work.
the fuel injectors may be different designs (peak and hold versus saturated) so the driver circuit in the ecu may be different
if the both your 86 and the 88 has the ballast resistor on the fender well it might work, if either one doesn't have the ballast it might not work.
do the part numbers match? (prolly not)

jasond

Go to this link for some good information..

http://www.pirate4x4.com/forum/showthread.php?t=247846

Dan.3

if possible try it before you by it. or compare the pin outs for the two wiring diagrams. ECU's are pretty much all the same except for the pin outs. You might have to repin the connectors. good luck

joesscamaro

The part numbers don't match. I can't remember the part number off the other computer I was looking at, but, 89661-35070 is the part number on the computer out of my 4Runner. Both computers have the same number of pins coming out of each plug-in. The lady at the shop said she looked up each part # and she said they were not compatible. They were asking $75 for the computer, so I may go back tomorrow and buy it and if it doesn't work, let me return it. Nobody has a computer they're looking to sell do they?

bjh900rr

The 88 computer will work, it may not run well, but it will run.
The only difference from the 86 to the 88 is the o2 sensor.
Its a 1 wire in 86 and a 4 wire in 88. So with that being said, you will probably get an oxygen sensor code while running the 88 computer in the 86.

It will run, and won't hurt any componets.

Just curious, why do you suspect the ecu? If the ck engine lite comes on with the key on engine off, I would lean towards something else to begin with. Ck for fuel pressure and ignition spark. You can jump the fuel pump test connector (T shaped, near the other round connectors), turn key on, and listen for the pump working/test fuel pressure. or just turn key on, and manually with your hand, open the air flow meter door to cycle the fp.

joesscamaro

I think it's the computer because that's the only thing left that I haven't checked. I've tested the fuel pump and that works....FPR works, that blad in the air flow meter is working....I have spark....and I have fuel getting to the rail....and I've taken the injectors out and cleaned them real good and still nothing. I was told a while back by a shop that they thought the computer was bad, and now I'm starting to think they were right. I dunno, I've run out of options/ideas, that's why I'm trying the computer. Thanks for the input. Any ideas though?

Flash319

The pickup in the distributor is what pulses the injectors. You need to have air flow through the AFM to turn the fuel pump on, then you need to have a pulse from this pickup to pulse the injectors. The ECU adjusts the pulse but does not make it. The pickup does. Swap distributors.

Also check that resistor that abec is talking about. These trucks are not multi-point, all injectors fire at the same time so start troubleshooting the pulse. I (think) the resistor is on the ground side of the injectors so you should still see a pulse on the power wires for the injectors if the resistor is bad.

These computers are very robust in my experience. So I would not suspect the computer.

bjh900rr

That resistor located on the pass. side fender is on the power side of the injectors. I believe the resistance should be 2-3 ohms through the resistor with it unplugged. The ecu controls the injector pulses by breaking the ground to the injectors.

If you have a noid light, just plug it into the connector for one of the fuel injectors and crank/run the engine. If it flashes, you know the electrical circuit is working.

Is your ck engine light coming on with key on, engine off ? If so, I would probably shy away from the computer being bad, but its still a possibility.

abecedarian

Not likely the distributor pick-up coil- there is spark.
I think you mean they are not sequential fuel injection....

the resistor has 3 terminals, two parallel and one perpendicular: |_| the two parallel ones are the out to the injectors, the other one is battery voltage (B+) in. so, check for batt voltage between that terminal and ground, with the key on. basically, if you have voltage at the ignition coil you should have voltage there, so if not, check that wire for breaks/opens.
then check the resistance between that B+ terminal and each of the other terminals in the resistor plug. resistance should be between 2 and 3 ohms, so a any meter with a .1x (1/10) scale works (reading would be between .20 and .30 on that scale). Avoid using a 1x scale on the meter because you could be out of spec due to rounding errors in the meter.
But it's not impossible.

mnmontana

I have a spare ECU, if you want to try it, swing on by.

joesscamaro

Haha, I would swing on by if you were on this side of the US. I live on the east coast of NC. I think I'm going to pick up that '88 computer and give it a try. I'll give yalls ideas a go too! I'll be back!

abecedarian

we'll be here.