Nailit69

So i'm putting a new motor in my truck https://www.yotatech.com/forums/f158.../#post52005247 and have come to what I hope is my last wrinkle to iron out.... an issue with my o2 sensor.

The sensor on the new motor is a single wire unit mounted in the header between #3 & #4 pipes. The one on my truck is a 4 wire heated unit located under the cab about 2' downstream.

Correct me if i'm wrong but wouldn't the easiest solution be to put another 4 wire unit back in the same location on the new exhaust rather than trying to make something different work?

One other question I have is w/injectors... I read somewhere that there are 2 different types (low and high impedance?) and they changed from one type to the other sometime in '88. What if any issues would I have related to this? Is it a "runs or doesn't run" situation or just a matter of switching computers or what? TIA!

Bassmastry101

iTrader: (1)

If its a 22re-22re swap, seems like the easiest thing to do would be use everything from the original engine, that way you won't need to modify or change anything but the engine itself.

Nailit69

That's my line of thinking... my problem right now is I have no exhaust and in turn... no O2 sensor. Can this affect the way it runs at idle? I don't really want to run it too long w/out it if it could cause problems. It's running a little rough but could be plug/wire related, didn't have much time to really check it out yesterday and i'm busy today so I might have to wait til tomorrow.

The only thing I changed from my original truck was injector plugs, I had to remove the stock injector wiring from my harness and used the wiring from the harness that came with the engine since it's supposedly a flow matched set. The original harness had been cut to harvest plugs needed for a 3.4 swap i assume... I wanted my uncut harness but wanted to stick w the injectors in the new motor.

Nailit69

Any suggestions as far as exhaust/mufflers goes? I'm planning on 2 1/2" from the header back, I hear the flowmasters sound pretty good. I spend quite a bit of time in my truck too so something that's too loud isn't really going to work for me.

snobdds

Weld up the hole for the one wire and use the origional sensor (4wire) that is one your truck. That would be ideal...

Nailit69

Do I need to weld up the hole or just leave it in there w/the O2 unplugged? There's a nice perch welded in there, couldn't I just cap it w/a plate too?

My plan is to re-install a 4 wire unit into the new exhaust where the old one was. Right now there is no sensor since there is no exhaust, just wondering what it might affect while i'm trying to get it running a little smoother.

toyquad

get the exhuast on. you need proper back pressure for a motor to run properly. you could be chasing a problem( runs rough) that will be fixed by simply hooking the exhuast up.

with the o2 sensor unhooked, the engine will stay in " closed loop" ( maybe its open loop) i forget which one is which, but the engine will not run at its best, the cel should be on.

if your cab/ ecm is wired for the 4 wire o2 sensor, i would use that.

hook everything up properly then see how it runs.

Nailit69

Thats what I was thinking, the CEL is on, I guess i'll get the exhaust on and go from there.

Bassmastry101

iTrader: (1)

Sure, leaving the 1-wire sensor installed and unplugged won't hurt anything..just plugs the hole.

I saw the swap thread and I'm curious...why did you swap harnesses?

Nailit69

I bought the motor from another YT member after he did a 3.4 swap And he must have needed part of the harness for that and it was hacked up pretty well. I disected the cut harness and used the injector wiring and put it into my harness. If I could have used it I would have.

Bassmastry101

iTrader: (1)

I got that part, I meant what was wrong with the harness already in the truck? Swap looks great! Just curious.

Nailit69

Different injector plugs. I kept my harness but wanted to run his injectors.

Nailit69

Just being anal I guess

Terrys87

iTrader: (1)

Stay with the 4 wire O2. Muffler shop can add a new sensor bung for very little cost. It is common practice in the muffler world as most O2 sensors get burnt up so bad.

88 is the oddball year on injectors >>> Link https://www.yotatech.com/forums/f116...ectors-127606/

No suggestions on exhaust, a good exhaust shop should be able to tell you what you need, but I do like to get my O2 sensors from www.sparkplugs.com Get what came with it factory and stay away from the genereic or one size fits all type O2 sensor.

Nailit69

I think my truck had the type E 2.5 ohm injectors and the new engine has the type C 2.5 ohm injectors. Do I need to be running a different ECM? I have the one that came w/that motor. I need to double check to be sure, but it seems like it should work.

One other thing... it has a LCE Big Bore throttle body and a Supra AFM, and just for the purpose of starting it i'm using the stock AFM/airbox until I can get the Supra AFM properly plumbed. Would this have any affect on anything?

Lastly... If I do use the other ECM do I need to use the single wire O2 or the 4 wireO2? What about a good quality/brand like Bosch O2 or should I get genuine Toyota?

Any help with this would be greatly appreciated, I need to get this thing back on the road ASAP!

Kelly00127

My 88 does not have an O2 sensor.

Bassmastry101

iTrader: (1)

Okay, I think I understand now. I was originally trying to say that if its a direct 22re-22re swap then nothing needed to be changed, only need to swap intake and sensors over to new motor. That way you wouldn't have to change what was originally there.

You basically just changed the plugs for the injectors, without hacking up the harness -- pretty clever. If the resistance is the same between the injectors there shouldn't be an issue (Type-C/Type-E).

About the o2 sensor, it depends on what ECU you decide to run with. If original ECU then keep original o2 and location. If you use the one from BBP, then use the 1 wire at the manifold.

Never use Bosch..stick with Denso.

Bassmastry101

iTrader: (1)

No worries. I'm currently changing my Accord over from carb to EFI so I know exactly how you feel.


Huh?

Nailit69

You got it now... i've done a few harnesses, as i'm cutting them apart I put a wrap of tape where a wire comes out of the loom and move on. When i'm done I hang it from a hook on the ceiling and start wrapping it back up using the wraps of tape to determine plug locations and plastic covering/guides/forms/fasteners, etc.. It works well for me, and I don't forget where a wire went, and it looks completely stock and brand new when it's done.

I wish the other harness was useable, it would have saved me some serious time, I might even be driving it right now instead of looking at it.

I'm going over to confirm the injector type, run the appropriate ECU and a new Denso O2 unit, get new pipes, tune it up and hopefully drive it... I CAN'T WAIT TO DRIVE IT!!!!.

Nailit69

Ok, so I confirmed that I do have the Type E/Type C 2.5 ohm injectors and my truck has a june '87 build date so I should be good, i'm sticking w/my ECU and I also got the 4 wire Denso O2 unit to put back in it's original location under the cab, just seems easiest that way. I still haven't made it in for exhaust yet but need to sometime this week.