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Discussion Starter · #1 ·
After months I finally gotten the MR Two on the road. The only problem is it has a slow acceleration almost like a resistance when pressing the pedal.

I’ve gotten the codes P0010, P0013, P0020, and P0023. I had changed all the sensors and it still won’t go away. I have changed the oil to 5w-30 instead of 0w-20. I don’t know if that is what is causing the codes to appear.

Car hasn’t gotten the spark plugs changed as well
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P0013 and P0023 look like circuit codes. I would double check continuity from the VVTi control valves back to the ECU, and double check that everything is pinned right at both ends (doubly so since the harness appears to be custom).
 

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I don't see any of the ground terminals that a factory engine harness bolts to the valve covers. Probably you are missing the ones that go the the cylinder heads above the transmission. I don't see the noise filters that ground the ignition coils. Here is a simplified Engine Control System Diagram. I would check that your harness provides all the grounds indicated. You may wish to check a more complete Engine Control Wiring diagram that calls out the locations of the ground points.
 

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Discussion Starter · #4 ·
I don't see any of the ground terminals that a factory engine harness bolts to the valve covers. Probably you are missing the ones that go the the cylinder heads above the transmission. I don't see the noise filters that ground the ignition coils. Here is a simplified Engine Control System Diagram. I would check that your harness provides all the grounds indicated. You may wish to check a more complete Engine Control Wiring diagram that calls out the locations of the ground points.
There’s a bundle of ground wires that are ground to bank 1. I’ll send a photo once I get home. Each valve covers are grounded with a 4 gauge wire. The bottom photo is the ground wire that runs from the transmission case (it’s an old ground wire from the previous engine)
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There’s a bundle of ground wires that are ground to bank 1. I’ll send a photo once I get home. Each valve covers are grounded with a 4 gauge wire. The bottom photo is the ground wire that runs from the transmission case (it’s an old ground wire from the previous engine)
Yes I did notice that you have some fat ground wires running from the engine to the frame. Those are complete overkill. Other than possibly the ground wire from the trans to the frame, that serves the return of the starter current, nothing else needs to be of that size. The crucial grounds you may be missing are those for the sensors, the ECU, and the shielding. Those are within the engine harness.

I would suggest that you grab a pocket oscilloscope, and check the quality of the waveforms for the OCV's and also the crank and cam sensors. I don't think that simple continuity checks are going to help you find the issue. In fact if you pass the simple continuity tests suggested in the factory service manual, the only remaining indication is to replace the ECM, but this would be assuming that you have a properly constructed undamaged harness (see attachment).
 

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Discussion Starter · #8 ·
Yes I did notice that you have some fat ground wires running from the engine to the frame. Those are complete overkill. Other than possibly the ground wire from the trans to the frame, that serves the return of the starter current, nothing else needs to be of that size. The crucial grounds you may be missing are those for the sensors, the ECU, and the shielding. Those are within the engine harness.

I would suggest that you grab a pocket oscilloscope, and check the quality of the waveforms for the OCV's and also the crank and cam sensors. I don't think that simple continuity checks are going to help you find the issue. In fact if you pass the simple continuity tests suggested in the factory service manual, the only remaining indication is to replace the ECM, but this would be assuming that you have a properly constructed undamaged harness (see attachment).
I’ll get an oscilloscope and get back to you on how it goes. Photo below is the grounds for the harness itself
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I’ll get an oscilloscope and get back to you on how it goes. Photo below is the grounds for the harness itself
How does the engine run if you disconnect the OCV's entirely. Same? Or different?

How does it run if you disconnect the MAF. Should fire after a couple of crank attempts, and run with a 3000 rpm rev limit.
 

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Discussion Starter · #12 ·
How does the engine run if you disconnect the OCV's entirely. Same? Or different?

How does it run if you disconnect the MAF. Should fire after a couple of crank attempts, and run with a 3000 rpm rev limit.
If I disconnect the OCV’s it still runs the same :/. I’ll disconnect the MAF sensor when I get home and tell you how it goes
 

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You can also try disconnecting the primary O2/AFR sensors. Engine will run in open loop. This affects only the AFR's at idle and cruise. Behavior under acceleration (open loop) should be close to normal. The ECU monitors a tiny milliamp current for the AFR sensors, very small variations in current give the measured variation in AFR - this is to say they are vulnerable to interference.
 

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Discussion Starter · #14 ·
You can also try disconnecting the primary O2/AFR sensors. Engine will run in open loop. This affects only the AFR's at idle and cruise. Behavior under acceleration (open loop) should be close to normal. The ECU monitors a tiny milliamp current for the AFR sensors, very small variations in current give the measured variation in AFR - this is to say they are vulnerable to interference.
So I noticed the SPD wire on my car is cut. I don’t know if that’s what’s causing the code but the Speed signal does show up on the diagnostic for OCV
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The custom harness I have has the SPD wire but it doesn’t run off to a speed sensor…
 

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Hm interesting possibility the speed signal is known to have something to do with the rev hang when you let off the accelerator.

Having the vss hooked up does make RPMs hang a bit with the clutch in at speed. This is a side effect of the automatic transmission stuff going on.
But not having it has never been known to cause any problem.

What do you have going on with your PRNDL wires. Optionally your choice either N or D should be getting 12v.
 

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Hey mark, sorry about this, its a much simpler issue. We were discussing this on reddit and the fuel injector connectors are just on the wrong bank. With these photos I can clearly see now they need to be swapped so the harness is installed correctly. Tan, yellow, purple are cyl 5, 3, 1 and are not supposed to be on 6, 4 , 2. Unfortunately things got a bit silent and I have no idea if anything has been done since.
I can also see that practically every vvt connector and is connected to the wrong part. It would really help if Rvin16 would respond back to me so I can actually help you get this working.

Rivn16, as I said on reddit, take off the plastic intake manifold. Take pictures of how you have things connected, show them to me and I’ll have you connect the correct plugs to the correct devices.
if you don’t respond, then at least for me, bolt down the harness. If you leave it just draped on the engine its eventually going to wear into the harness.
 

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Discussion Starter · #17 ·
Hey mark, sorry about this, its a much simpler issue. We were discussing this on reddit and the fuel injector connectors are just on the wrong bank. With these photos I can clearly see now they need to be swapped so the harness is installed correctly. Tan, yellow, purple are cyl 5, 3, 1 and are not supposed to be on 6, 4 , 2. Unfortunately things got a bit silent and I have no idea if anything has been done since.
I can also see that practically every vvt connector and is connected to the wrong part. It would really help if Rvin16 would respond back to me so I can actually help you get this working.

Rivn16, as I said on reddit, take off the plastic intake manifold. Take pictures of how you have things connected, show them to me and I’ll have you connect the correct plugs to the correct devices.
if you don’t respond, then at least for me, bolt down the harness. If you leave it just draped on the engine its eventually going to wear into the harness.
Hey I’m sorry for the very late response and dead silence. I appreciate the help you have given me. I had my media devices stolen recently but that has been resolved. I still owe you a reward as I promised on reddit

But yes, I have swapped the fuel injectors to their correct cylinders. The photo shown below is before I changed the fuel injectors connectors.
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The car accelerates much better now and doesn’t overheat as it did before. The only problem is when I drive in 5th gear it stops going past the 4k rpm mark. If I rev it higher in lower gears it still revs but at a slow rate. The car also has random backfires as well. Possibly from vacuum leaks

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The photo shown above is what I used to pinout the wiring to the OCV. I can provide a better picture tomorrow morning on OCV connectors to see if they’re plugged in correctly.

Once again I apologize for the dead silence.
Thank you again
 

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Glad its going better now.
Next up you'll want to check the ACIS (intake manifold) and VVT solenoids. Its very likely you have the ACIS connector plugged into one of the VVT Solenoids since toyota used the same plug for all of them. If you have a photo of what wires are connected to which we can get that sorted out next.
ACIS (on the side of the intake manifold): Red & Gray Wires
Bank1 Intake VVT Solenoid (Trunk side of the engine, solenoid closest to the intake manifold): Purple & Dark Green Wires
Bank 1 Exhaust VVT Solenoid (Trunk side of the engine, solenoid closest to the trunk): Dark Blue & Gray Wires
Bank 2 Intake VVT Solenoid (Headlight side of the engine, solenoid closest to the intake manifold): Tan & Light Green Wires
Bank 2 Exhaust VVT Solenoid (Headlight side of the enigne, solenoid closest to the headlights): Yellow & Light Blue Wires

Pictures are very welcome, it helps verify things look correct when diagnosing
 

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Discussion Starter · #19 ·
Glad its going better now.
Next up you'll want to check the ACIS (intake manifold) and VVT solenoids. Its very likely you have the ACIS connector plugged into one of the VVT Solenoids since toyota used the same plug for all of them. If you have a photo of what wires are connected to which we can get that sorted out next.
ACIS (on the side of the intake manifold): Red & Gray Wires
Bank1 Intake VVT Solenoid (Trunk side of the engine, solenoid closest to the intake manifold): Purple & Dark Green Wires
Bank 1 Exhaust VVT Solenoid (Trunk side of the engine, solenoid closest to the trunk): Dark Blue & Gray Wires
Bank 2 Intake VVT Solenoid (Headlight side of the engine, solenoid closest to the intake manifold): Tan & Light Green Wires
Bank 2 Exhaust VVT Solenoid (Headlight side of the enigne, solenoid closest to the headlights): Yellow & Light Blue Wires

Pictures are very welcome, it helps verify things look correct when diagnosing
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So I made sure every connector is plugged to the correct Solenoid. The CEL still pops up for all four oil control valves and instantly when I clear the codes. The solenoids are within ohm specs and operate when applied 12 bolts.

I’m starting to believe I may have fried the ECU a couple months back when I blew the ECU-B & AM2 fuse…

I checked the resistance on the ECU pins themselves and I only get continuity between pin 49 and 51. The resistance came out to be 1.3 ohms. If I check between 56 and 55 no continuity is shown.
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Based on your pictures and testing notes it looks like you’ve been able to independently verify that the vvt solendoids are connected correctly which is great. The pictures you provided look good.
As far as checking continuity on the ECU pins, for the vvt solenoids one side is a high side driver (connects each vvt+ to 12v) and the other is low (connects each vvt- to gnd) I’m not sure that I would test between each vvt+ & - for an individual driver pair but your test clearly indicates inconsistent behavior on 4 identical circuits within the ECU. Your continued codes even after you have verified the rest of the electrical system is operating within spec and strange engine characteristics certainly lead me to conclude the same thing you are suspecting, that the only remaining likely cause is the ECU.

However, if you want to address the vacuum system I can try and help with that. For the purposes of testing. There should be only the vacuum brake booster connected the the black manifold. If you dont want power brakes, you can plug that too. You can plug all other extra ports on the manifold & intake. For now lets leave the PCV system disconnected. For diagnostic purposes this won’t cause any issues but it will be a good idea to get them re-connected when you’re done.
Lets also disconnect the VVT solenoids. The engine should run at its normal camshaft timing for the whole rev-range and this is fine. For maximum power output we’ll want them reconnected but for diagnostics its not an issue.
In your intake, make sure your MAF sensor is mounted vertically where the little sensor elements are hanging from the roof of the intake pipe, not poking up from below.
Make sure your engine is filled with water/coolant and the temp sensor is connected.
In this configuration, should everything be operating correctly, the engine should idle and rev just fine in neutral with not a care in the world.
One thing I’d like you to test is if the crankshaft position sensor connector is fully seated. If you unplug the connector, check for any obvious debris inside the connectors and then re-connect them until the little white plastic licking tab springs back into place with a shark click.
 
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