Rum_Runner

My brother is working on a project truck he picked up: 86 4runner with a factory turbo, blown motor. He's dropping a rebuilt 22re out of a 91 4runner into the 86. Is it necessary to swap the harness/ecu from the 91? Other than maybe an annoying constant check engine light, is the fuel/air delivery programing significantly different enough between the turbo and the n/a version to cause a performance issue?

abecedarian

yep, it's significantly different.
air/fuel ratios and timing maps are different

Rum_Runner

Thought that might be the case. Is the ecu/engine wiring easily separated from the rest of the harness?

abecedarian

able to be separated? yes. easily? no.
on the upside, installing a 22re into the truck shouldn't cause to many issues with smog checks and such since the 22re was available in the 86. However there are some slight differences between the 86 and 91 22re's such as diagnostics and some of the smog stuff so to be legal all of the 91 engine needs brought over (power steering and alternator don't, unless you want to).

Out of curiousity, what is 'blown' in the rte that your brother doesn't want to fix it?

Rum_Runner

He bought the truck locally a month ago for about $400. It's very clean, SR-5, even has the digital gauges. The guy he bought it from managed to damage the motor somehow so he tore it apart and decided he didn't want to try to rebuild it. We took a look at the block and the cylinder walls were gouged to severely for a rebuild, then he found the 91 that someone had just rebuilt the motor and then rolled it the next week.

mistreatedtoys

I disagree it is a very simple swap..if the parts are there. Just use the long block from the 91. Use the turbo intake and injectors so all your wiring will hook up. Use the turbo distributor as it has a different advance so a little more power. The radiator will need to be taken to a shop and the top port for the turbo coolant willl need to be brazed shut. As for the air flow meter which is the only major difference. The 91 might plug in if not you can adjust you turbo one to work. The turbo pulls more vacuum so there is more tension on the spring under the lid.

abecedarian

Yes it's a fairly simple 'engine' swap if you only swap the 22re longblock and exhaust. However the 91 intake is different than the 86. The 86 throttle body is down-turned therefore could not use the 91 cross-over duct since the 91 comes out horizontal. The duct from an early 22re would be required.

I'm interested in the theory of the 22RTE distributor as it's my indication the distributors are the same, at least with regards to an 86 22RE. The timing on a 22RTE is handled by the ECU similarly to the 22RE- by the ECU maps. The 91 distributor is a different part number, but not because of the timing curve being handled by the distributor- different hall-effect pickups.
22R distributors have adjustable plates to respond to varying vacuum conditions in the engine.

The AFM may be a valid point due to the increased air flow (not vacuum) required by the turbo. This would mean though, that the turbo afm is calibrated is differently... however a part number cross-reference suggests that the 86 22RTE uses the same air-flow meter as an 86 22RE, thus negating that claim.

Not trying to be the south end of a north-bound mule, but what you said (which I addressed) appears incorrect.

abecedarian

To continue-

the differences I mention are the primary reason why you'd want to use the harness and ecu from the 91 22re... in order to maintain a consistant, homologous system where everything in the engine bay is from the 91 thus guaranteed to work with the 91 ecu, etc. as opposed to hack and grab to make it work.

mistreatedtoys

I have just done this on a 86 runner. I do not understand why he would want to maintain all of the parts off the 91 of course California has many different laws. There is probably nothing wrong with the 86 parts and all that would be needed is the long block. As for the distributor I was told it had a slightly different timing curve. I am not 100% sure but it doesnt hurt. I am sure the injectors off the turbo might flow a little more but do not have any facts to back it up. Same with the throttle body etc. It would just seem as it should. The first swap I did I put a turbo in a non-turbo 87 truck. It worked great and was pretty easy.As I said on the AFM. if you remove the top cover on the inside you will find a spring held in place by a clip. the turbo will have that spring tighter than a non turbo. Just do not let that spring go., and take a little tension out of it.(mark original location) This works in conjunction with the throttle positioning switch to tell the engine how much air to fuel. You can drive it and you o2 sensor will tell you if you are to rich or lean. You will get a check engine light check the code to find out to rich or lean. It takes some time but works. It is always better to have it rich than lean. Once you can get the light to go off just fine tune by checking the plugs. Or better yet find a AFM off a non turbo truck. I recommend buying a factory service manual from toyota before starting and not a chiltons.

abecedarian

It's all good.
Like I said before- the AFM and distributor are the same for an 86 turbo (22rte) or non-turbo efi (22re).
There are differences between the rte and re ECU though that shouldn't be ignored. For the most part swapping the engines will result in a running truck, but it won't run as well as it could.
That is all.

saitotiktmdog

Why not just rebuild the turbo engine?