Build US Spec. February 1990 Poverty 80 2uz/h151f swap

[Tank5]

I need to write this out as part of the thinking process. Currently the engine has no power. If I floor it it doesn’t respond, it will slowly increase speed like it is in some sort of limp mode.

• Just received the harness back from the stand alone builder. The wiring was completely redone.
• The engine ecus as far as I know were not changed.
• I don’t have any trouble codes or pending codes that I see in techstream
• Fuels Trims look good
• The air intake is clean and unobstructed.
• The throttle plate is opening all the when I tested it
• Fuel Pressure is 41-44 psi
• The spark plugs are new and don’t show anything abnormal
• A compression test for each cylinder was completed earlier in this thread and compression was within spec.
• Checked timing again and it looks correct.

It has fuel, air, and spark, further the ecu appears to be happy, but it doesn’t drive like it is happy.
The engine mechanically appears to be fine. The harness has been gone through and as a stand alone harness it only needs three wires wired to run the engine. 12v IGN to the ecu another 12 volts to the starter and ecu to the fuel pump trigger. With that I should be able to run it down the road.

What am I missing?

 

[Tank5]

Have you ever taken the cams out?

I have not removed or done anything with the cams..

 

[Skter505]

Sure sounds like you are in limp mode, that is exactly how it feels. Real strange there are no codes though. Have you checked your readiness monitors? I'm betting it's something with the secondary air injection.

 

[Tank5]

Sure sounds like you are in limp mode, that is exactly how it feels. Real strange there are no codes though. Have you checked your readiness monitors? I'm betting it's something with the secondary air injection.

I agree it seems like it is in some sort of limp mode. It is odd though that there are no trouble codes.

I have a Silverado work truck that was having a transmission issue and when the issue would surface it would go into a reduced throttle mode. In this mode it would accelerate but very slowly. Even if you push the pedal to the floor it would not really respond but would slowly accelerate.

The 80 is pretty much acting the same way. Press the pedal to the floor and it will slowly speed up but it will top out depending on the terrain. I never got it above 3 rd gear on the most recent drive.

 

[Skter505]

The tuner is absolutely sure all the automatic logic is flashed out of the ECU? I didn't realize how long youd been fighting this. The Air injection is a common bypass, not sure how common manual swaps on VVTI equiped 2UZ's are though. I'd be assuming there's some problems somewhere along those lines. With the manual swap does it still require a speed sensor from the output shaft, and you have one? It's possible a simple Park/Neutral fooling of the ECU isn't enough for the more modern ECU.

I don't have any experience with swapped 2UZ's and ECU tuning, only on the OE side so sorry I can't be more help.

 

[Tank5]

The tuner is absolutely sure all the automatic logic is flashed out of the ECU? I didn't realize how long youd been fighting this. The Air injection is a common bypass, not sure how common manual swaps on VVTI equiped 2UZ's are though. I'd be assuming there's some problems somewhere along those lines. With the manual swap does it still require a speed sensor from the output shaft, and you have one? It's possible a simple Park/Neutral fooling of the ECU isn't enough for the more modern ECU.

I don't have any experience with swapped 2UZ's and ECU tuning, only on the OE side so sorry I can't be more help.

I have asked the tuner about the possibility of the transmission delete having an issue and he seems adamant it is not the issue. I am not saying it is but I cannot say it isn’t. I did just get the ECUs back and I am not aware there there were any changes made to the ecu.

I’m talking with another member out side the forum who is also curious about the transmission bypass delete being a possible culprit.

 

[ceylonfj40nut]

Do you know of another tuning/ ecu flashing outfit that could reset your ECU to your needed specs?

 

[Tank5]

There is another and I am considering just buying an additional tune ecu. It is not cheap though, so I have not jumped on it yet. It is definitely an option I have been considering.

 

[ceylonfj40nut]

So is one lesson here for us mortals is that vvti engines are more tricky to swap than non- vvti?

 

[Broski]

So is one lesson here for us mortals is that vvti engines are more tricky to swap than non- vvti?

I would say it's more to do with the 5 speed manual swap going in at the same time IMO

 

[Tank5]

So is one lesson here for us mortals is that vvti engines are more tricky to swap than non- vvti?

It would appear that there is something tricky about the vvti. I do know of at least one member who swapped a manual 2uz VVTI into a 40 series, so it can be done. I feel closer than I have been.

 

[thepinktaco]

Don’t know how he modifies the ecu for manual swap but I wonder if it has a rev limiter when in park. Cant remember if the 2uz does or not but that would usually limit to 3500ish rpm’s. If the data list shows park maybe this is the issue and triggering the drive signal to the ecu might change it.

 

[Tank5]

Don’t know how he modifies the ecu for manual swap but I wonder if it has a rev limiter when in park. Cant remember if the 2uz does or not but that would usually limit to 3500ish rpm’s. If the data list shows park maybe this is the issue and triggering the drive signal to the ecu might change it.

The ecu is wired so that it always thinks it is in gear. It will rev above 3500 rpm just not under load unless I have a long down hill section of road that will allow it to slowly get up to speed to rev that high.

 

[matzell]

Any restriction in exhaust? I know you have checked fuel pressure. What is factory pressure spec? Is volume good? What size fuel line are you using?

 

[Tank5]

Any restriction in exhaust? I know you have checked fuel pressure. What is factory pressure spec? Is volume good? What size fuel line are you using?

No restrictions in the exhaust, Factory fuel pressure is between 38 and 44 psi. My fuel pressure is consistently within that spec on the higher side. It maintains fuel pressure under load as well. I am using the factory 80 series fuel lines.

I don’t think volume is an issue as the pressure is maintained under load. It doesn’t drop due to demand which I would expect it to if there was not enough volume. I have also tried clamping the return line and that made no difference.

 

[mrsleeve]

Since your going manual and the lack of slush box. I know Tim was supposed to handle all of it on his end, have you thought about emulating the TCC sensor, the input/output speed sensors or the foot on break safety before shifting into gear switch ? Or some combination of existing sensors or switch’s sending conflicting info to your current ecm and not playing nice ?

 

[Tank5]

Since your going manual and the lack of slush box. I know Tim was supposed to handle all of it on his end, have you thought about emulating the TCC sensor, the input/output speed sensors or the foot on break safety before shifting into gear switch ? Or some combination of existing sensors or switch’s sending conflicting info to your current ecm and not playing nice ?

I have considered that there may be something such as you have suggested that the Cubs looking for and not getting. I have not tried to wire anything extra into the ecu that it has not presented a trouble code for. Tim’s harness as build does not specify the need to wire in either of the sensors you identified. I know that some of the systems Tim has deleted the need for in the programming and I am hesitant to add circuits or sensors to the ecu and complicate it more should I cross something up.

I am very reliant on Tim to get his part right for this to work. I know he is looking at getting some other programming specs for the ecu and is going to reprogram my second ecu with a new program.

 

[matzell]

Do you have a decent scanner so you can watch what the timing is doing while driving? I wonder if the VVT is working as designed. May not be getting timing advance as needed?

 

[alia176]

Do you have a decent scanner so you can watch what the timing is doing while driving? I wonder if the VVT is working as designed. May not be getting timing advance as needed?

he reported multiple times about using Techstream do all this troubleshooting.

 

[matzell]

he reported multiple times about using Techstream do all this troubleshooting.

Thank you. That answers part of it. The main question is does the timing change with rpm? Vvt will act like this of not working properly.

I am not guessing, I work on cars for a living. Fyi.