Toyota 22R-E air/fuel ratio ECU coolant signal hack / bypass tuning module for hesitation lag at WOT

[@99FXR]

I think you have the most checked, efficient and CLEANEST 22RE I've ever seen..it's always an inspiration

[@ray5961]

Thanks very much; appreciate that :)

[@cbh148]

This is a sweet idea. Took me a moment of looking at your diagram to realize that the potentiometer only adds resistance on top of the still-included coolant temp sensor, rather than the switch simply swapping from temp sensor wholly over to the pot. I love endeavors like this with thoroughly lateral thinking.

[@ray5961]

Thanks man. Yeah, the potentiometer is wired in series with the coolant temp sensor, so whatever the potentiometer is set to, that resistance is added to the resistance of the coolant temp sensor. I usually avoid any sort of high RPM's or WOT operation on the truck until both engine and gear oil have come up to full temp (at least 5 miles of driving from the house minimum) so by that time the resistance from the factory coolant sensor should be down under 200 ohms I would think.

[@regularguy8592]

Ray I have almost got Haltech 750 Elite installed on mine, Cranked it up today and have it running but not perfect yet. That Gabe from SNP has been good as gold helping me out when I have questions. I have the Haltech dash and pdm16 on order but not come in yet

[@regularguy8592]

really good video! My engine is a lot like yours not stock anymore ,A few days ago I installed wide band afr sensor and gauge, mine is running rich at Idle around 9 and from half throttle to wot it runs on the lean side at first then tries to recover somewhat. I removed the plug over adjusting screw on map sensor and so far have backed it out 3 turns, Now it may be a bit better but not much ,I need to drive it more at this point to get a better idea, Most likely this summer Im going to rip my ecu out and convert to Haltech ecu but I'm going to experiment more with what I have first. My truck is 4wd ,33 tires ,5,29 gears. Engine is stage 3 Yota1 with Lc header and exhaust ,10 to 1 pistons, LC big bore throttle body ,trail gear extreme breather. I'm only getting a little over 10 mpg at this point and I don't feel thats good at all

[@ray5961]

Which wide band controller / gauge are you running? Are you running in air/fuel ratio or lambda? When you say 9 do you mean .9 lambda or do you mean 9:1 AFR for gasoline (where 14.7 is stoichiometric)? 0.9 lambda is fine.. AFR of 9:1 is crazy rich. Have you changed the clicks on the AFM as far as that internal coiled up spring goes? That little adjusting screw on the AFM is a fine tune adjustment at most. 10 MPG sounds like something is very wrong. Just to give you an idea, with my truck, I am running 4.11 in the back with a W58 gaerbox and 29" wheels (granted, they are on very light weight forged racing wheels). Each tire/rim combo is ~ 45 lbs on my truck, whereas 33's and heavy rims could be pushing more for your rig. But I drive pretty hard and still manage 20 MPG around town (91 octane) and usually 24-26 MPG cruising 75-85 on the highway. Are you adjusting for the gear ratios and wheel ratios and all that? On my truck, my speedometer reads off by 5% so I have to compensate for that when dividing out miles at each fill up vs. gallons of gas going into the tank.

[@regularguy8592]

you should shoot some video of the afr gauge response with and without this switch setup

[@ray5961]

I might use that as a pickup line: "Hey baby, wanna help me make a KZbin video about my wide band O2 gauge?". Video taping and driving with one hand is a bit tricky over here sometimes.

[@bzerob3400]

Hey Ray. I'm new to the channel anyway I just bought a 91 pickup and have started the resto. I was watching a video of yours from 2 years ago and noticed your speedometer cluster looks brand new. Just was wondering if you had it rebuilt, bought a new/used one or did you just get a good one to start with. By the way good stuff.

[@ray5961]

Hey congrats on the truck. On my dash I bought a used SR5 dash off ebay and cleaned it up a bit before install - also used LED bulbs

[@scrappyjackalope9558]

You have done a lot of mods, but your head, exhuast and cam are now being limited by the stock intake, plenum afm and plastic tube. 22re performance has done a lot of dyno work finding that out as I am sure LCE has as well. Are you in an area where you have to smog? Reason being you are limited out at this point and if you really want to make real improvements on your 22re you need to do some real changes with your intake system. Also with your love of tuning etc I would go the a aftermarket Haltech ecu like Gabe with SNP uses(which LCE works with) At some point you get to diminishing returns with your current bottle neck. Have fun..

[@ray5961]

This is about it for the 22RE motor. I'm working on a 3RZ turbo to replace it. On that motor, I'll probably run the Link ECU instead of the Haltech stuff. Yeah, Gabe does nice work at SNP and I enjoy following his tuning stuff. On my 22RE I did port match the intake manifold, but as you say, the stock throttle body and plastic intake tube is probably not helping - although I don't believe there is any vacuum being pulled at WOT, so it's hard to say. With the current modifications, the 22RE runs nice. I'd actually be really curious to see how this particular motor would run with dual side draft carbs :-)

[@regularguy8592]

hey Ray I second the motion with you going to Haltech ecu, that way by the time I change mine over you will have all the bugs worked out and tuned in all I have to do is watch the videos 😁

[@ray5961]

@@regularguy8592 Haha perfect! I think I'm probably going to run the Link ECU. I do love the Haltech dash though.

[@poivre22]

Fantastic hack! 👍 what kind of bump do you guesstimate you’re getting when you’re up in the revs? 10 HP?

[@ray5961]

With the modifications I have on the motor, I would guess I'm making around 135HP or so. This modification doesn't add power, but rather it prevents the motor from going lean and causing power to drop off. Before this modification, if I gave the truck full throttle, it would lag (kinda like turbo lag back in the 80's or 90's). The A/F would go very lean and it would take maybe 3 or 4 seconds for the motor to get back into a reasonable A/F ratio for acceleration. But with this mod, it's pretty much instant now: if I hit the accelerator (full throttle), the A/F ratio immediately go down to .90 lambda (or so) and the truck accelerates very smoothly. It feels much more like a rocket now.

[@poivre22]

@@ray5961 makes sense. You better be careful though. Any more neat mods like this and you’re not going to want to ditch it for a 3RZ turbo. 😉

[@ray5961]

@@poivre22 haha that's no joke! I love the little 22RE, but it's gonna have to make room for the turbo 3RZ one day. But I'm thinking I might buy a 1st gen 4Runner down the road for my daughter, then teach her how to rebuild motors by tearing down the 22RE and refreshing it and putting it into the 4Runner w/ her.

[@cbh148]

Does your truck still have the factory VSV setup for the fuel pressure up? Not sure how much of a factor it is as I removed it from my '94 when I had the engine out and everything apart years ago.

[@cbh148]

Also, I can't remember if that fuel pressure up VSV being triggered is what the "fuel enrichment" flag on the stock ECU's data stream corelates with, or if that flag was just something added on top of whatever the fuel table's lookup value instructs, but I know when I connect my ToyOBD1 bluetooth dongle thing to the truck and watch the data stream, it triggers that function when I give it lots of throttle.

[@ray5961]

I no longer have the fuel up VSV in the loop; the vacuum hose runs direct to the regulator.

[@abregochristopher]

Is it just keeping the cold start injector on also when you go WOT since its goin off the coolant temp?

[@ray5961]

No what it's doing is increasing the pulse duration of the main injectors

[@haanichargualaf7293]

Is it possible to use this kind system for bigger cam n valves that ecu can’t handle or custom intake with stock maf n tps?

[@ray5961]

Usually the issue with bigger cams (with a lot of overlap) is related more to vacuum (or lack thereof) issues I think. But if you mean just in general with cams and heads that are not recommended for the stock ECU, it's hard to say for sure. I think the LCE tuning module might work better than what I have setup here, since it modifies the fuel tables across the board. However, when it comes to wide open throttle, this modification would help for sure (i.e. when running in open loop). I'm not sure where the dividing line between "being able to get the stock ECU to work" vs. "needing to run a full blown custom engine management ECU" is. I think the only way to know for sure is to run a wide band controller and see how the A/F ratios respond. I do think it's interesting to note that on my motor (which is modified, cam, valves, exhaust, etc.) the best A/F ratio for cruising is achieved by running my AFM one click leaner (although I do have a re-manufactured AFM from Napa, so who knows it if came out of the box matching Toyota's factory settings). It does seem like you can get the motor to run quite well by tweaking the AFM and also hacking the THW signal. I don't know if that's as good as running a Link ECU or Haltech or something, but my truck runs amazingly well off the stock ECU.

[@haanichargualaf7293]

I actually have the tuning module from LCE with a wideband but I was worried about afr at wide open throttle haven’t set it up yet but thank you for confirmation I’m in the right direction 👌🏽

[@ray5961]

@@haanichargualaf7293 If you already have the LCE pro tuning module, that's a good start. What you really need though is a wide band O2 sensor and gauge, so you can monitor exactly what is happening. Without that, you are kind of just flying blind. But if you have that, then I think I would install the LCE pro tuning module and see how the motor does cruising in closed loop operation and then see what happens when you go WOT on flat ground. If the truck hesitates and the A/F ratio goes real lean, then doing the upgrade I did on top of the LCE module would certainly be possible; you can just stack their potentiometer in series with an additional one that triggers only at WOT. That's basically how I have mine setup.. it adds the resistance on top of the coolant sensor. You could setup something which works similar, although there is a limit to the total resistance range the ECU will adjust for. Having the wide band O2 sensor really helps you tune things though. Without that, it's very hard to see what the ECU is attempting to do in terms of A/F ratios under different operating conditions on the road.

[@dustinn5490]

I know you have more important things to do in life, but I’d buy that as a kit if you were to offer them 😉

[@ray5961]

Thanks! I probably won't be going into the Toyota custom parts business anytime soon, but I appreciate the vote of confidence :)