Hope you can check vacuum somehow. Are there other 2uz tuners out there that you could send ecu to?
Builds US Spec. February 1990 Poverty 80 2uz/h151f swap
- Thread starter Tank5
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Tank5
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- #322
I purchased a vacuum gauge and might get to test that tonight after the gas smell in the garage dissipates. I talked to another shop that tunes 2uz’s and they said the chance of two ecus failing the same way are extremely unlikely. We talked about the differences in the LC/GX470/4runner even 2uz VVTI and he says it is extremely unlikely it is a programming issue. He was supper helpful and talked me out of sending my ecu to him to have it checked or re-tunned.
I shared the issues I am having and he thought it sounds like a fuel volume issue, so either a bad pump or obstruction. So I tested for that.
Tank5
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- #323
It was suggested my lean issue might be a volume issue, meaning I might have an obstruction or bad pump. In order to test this I took a second working pump for a 2uz that I had, attached to a spare sending unit and dropped it in a gas can. I then bypass all the fuel lines and ran the sending unit directly to the fuel rail with a new filter inline before the rail. I hooked the fuel line up using a canabalized banjo fitting from my other parts engine. So it was delivering fuel at the rail like the oem set up.
I hooked up a fuel pressure gauge to track that. Fuel pressure stayed strong and consistent. It was reading a little higher this time 49-50 opposed to 45-46.
I ran it at idle and there was no improvement in the fuel trims compared to pretest data.
Live Data at idle.
Live Data holding 3100+ rpms for more than 10 seconds to see if the FTs improved, suggesting a vacuum leak. They did not.
I am using the right pumps for the engine. Both pumps perform equally, so I think the pump is working as it should. Having eliminated the entire fuel line to the rail, I don’t believe there is an obstruction.
I hooked up a fuel pressure gauge to track that. Fuel pressure stayed strong and consistent. It was reading a little higher this time 49-50 opposed to 45-46.
I ran it at idle and there was no improvement in the fuel trims compared to pretest data.
Live Data at idle.
Live Data holding 3100+ rpms for more than 10 seconds to see if the FTs improved, suggesting a vacuum leak. They did not.
I am using the right pumps for the engine. Both pumps perform equally, so I think the pump is working as it should. Having eliminated the entire fuel line to the rail, I don’t believe there is an obstruction.
Tank5
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- #324
@ceylonfj40nut I hooked up the vacuum gage to the port right above /behind the throttle body.
With the engine idling it hold steady at 16. When I rev the engine it drops almost to zero and snaps back to 19-20 and then slowly settles back to 16. My learners permit here says this seems ok but please correct me.
I live at 7800 feet and I read that you subtract 1hg for every 1000 feet from the reading. I am not sure how to apply this to my results. Does it mean my normal reading at 7000 feet should be 7hg lower as acceptable or my test minus 7hg is what my test actually is?
I will do some research.
With the engine idling it hold steady at 16. When I rev the engine it drops almost to zero and snaps back to 19-20 and then slowly settles back to 16. My learners permit here says this seems ok but please correct me.
I live at 7800 feet and I read that you subtract 1hg for every 1000 feet from the reading. I am not sure how to apply this to my results. Does it mean my normal reading at 7000 feet should be 7hg lower as acceptable or my test minus 7hg is what my test actually is?
I will do some research.
My vac experience is on 2Fs in DFW. Good motor usually pulls 18-21” of vac and needle should be steady. If the needle flutters at idle, it means other issues in the body engine. Looks like your altitude adjusted value is about right and seems steady. Vac typically drops and snaps back when you increase rpm/ throttle.
Vacuum is created by piston action on the downstroke. If your smoke tests and vac tests show things are good, only way I see to have a lean condition is a restriction in the air intake at higher rpm or a sensor sending a false output to the ECU.
Can you trick the ECU to show primary O2 sensors that play a part in AFR adjustments are “not lean”? See what that does? I cant recall what was stated prior, did you swap out primary O2 sensors to eliminate that possibility? Is the wiring/ connections for O2 sensors all good?
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Tank5
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- #327
@ceylonfj40nut Thanks for the advice and read on my results, the vacuum test makes sense and does rule some possible causes out.
After posting last night I did some more reading regarding how it is affected at altitude. Considering I am at 7800 feet my reading stead at 16 hg indicates the vacuum is in the acceptable range. The needle doesn’t flutter or wonder at all.
After posting last night I did some more reading regarding how it is affected at altitude. Considering I am at 7800 feet my reading stead at 16 hg indicates the vacuum is in the acceptable range. The needle doesn’t flutter or wonder at all.
Tank5
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- #328
I did have to diagnose the A/F sensor issue which I solved but in doing so I purchased new oem sensors and installed them.
While watch the tech stream I can view the A/F sensor reading and force them in to a lean reading by continuously pump the brakes. Then as soon as I stop the A/F sensors return to their original reading. This I can see the A/F sensors working in real time to confirm they are functioning properly. I have accepted this test as confirmation the A/F circuit and sensors are working correctly.
Tank5
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- #329
I feel like I have about exhausted the list of tests I have the tools to work through to diagnose this issue. Mechanically I cannot find a cause for the lean condition which leads me too lean into the ecu or harness?
Currently contemplating starting over with a new harness and ecu and same engine or pulling the VVTI and installing a non-VVTI engine. I have an AU spec. OEM ecu for a manual transmission non-VVTI ecu, so I would just need to build a harness for it. Well and buy another engine.
I‘Ve invested a bunch on this engine, so it is hard to just throw that away at this point. It is pretty annoying. I need to step away for a little bit, think and regroup to figure out what my next steps are.
I really appreciate all help I have gotten on the forum and those that I have talked with outside of the forum. I am not giving up on this build but I do need to figure out what direction to pursue at this point.
Currently contemplating starting over with a new harness and ecu and same engine or pulling the VVTI and installing a non-VVTI engine. I have an AU spec. OEM ecu for a manual transmission non-VVTI ecu, so I would just need to build a harness for it. Well and buy another engine.
I‘Ve invested a bunch on this engine, so it is hard to just throw that away at this point. It is pretty annoying. I need to step away for a little bit, think and regroup to figure out what my next steps are.
I really appreciate all help I have gotten on the forum and those that I have talked with outside of the forum. I am not giving up on this build but I do need to figure out what direction to pursue at this point.
Looping in @Zjohnsonua
You said it popped p0430. Which is a cat code. Which with the rear o2 sensor deleted from the r ecu there should be no way for it to determine that they are bad. Front a/f sensors “run” the af ratio along with other inputs. The rear o2’s are really just checking that the cats are doing their job. That’s what over seas trucks don’t have rear o2’s. Another variable possibility is u have headers. Is the ecu tuned? For the head mod especially with so many related systems on the headers deleted? It is very possible that the extra flow in the exhaust can be causing the issue. The ecu is simply trying to compensate for the flow. Which is where a tune comes into play.
Like someone said earlier. Sounds like an ecu issue. Not that it’s bad. But how it’s set up.
Like someone said earlier. Sounds like an ecu issue. Not that it’s bad. But how it’s set up.
Glad to hear you still want to finish it off even it means a pivot and worse case a different 2UZ.
With that said, I noticed on North West Toys website lists Off Road Solutions in Colorado as their partner for engine harnesses. It seems like they also have a shop as well, so they might be able to help with diagnosing as well. Might be worth an inquiry, but also get starting with a fresh set up.
Tank5
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- #334
Thanks to @thabruiser who noticed that my atmospheric pressure seemed off and after he talked me through what that meant I had much better understanding of how it should probably read. This conversation sent me researching and I figured out that my MAP sensor is not hooked up to the planum as it should or so I think.
Originally I installed a SAI deleted kit which allowed me to remove all of the SAI parts but the map sensor, I didn’t know at the time that is was the map sensor and figured it was a part of the SAI system that had to stay to make the delete kit work. So I left it in place. Later I learned the the ecu programmer could delete the kit all together, so I did that and removed the delete kit but left the sensor in place because I didn’t want to pull the intake off.
The MAP sensor has been sitting like that taking its reading from the atmosphere and not hooked up to the planum. My research showed that a bad or failing map sensor can produce a number of symptoms like what I am experiencing.
Looking at the diagram that little vacuum hose nipple was plugged into the SAI pump, I am going to hook it up to the bottom of the planum and see what happens.
Will this solve the issue, don’t know and I am not getting my hopes but it appears not to be setup like it should be, sooo…
Originally I installed a SAI deleted kit which allowed me to remove all of the SAI parts but the map sensor, I didn’t know at the time that is was the map sensor and figured it was a part of the SAI system that had to stay to make the delete kit work. So I left it in place. Later I learned the the ecu programmer could delete the kit all together, so I did that and removed the delete kit but left the sensor in place because I didn’t want to pull the intake off.
The MAP sensor has been sitting like that taking its reading from the atmosphere and not hooked up to the planum. My research showed that a bad or failing map sensor can produce a number of symptoms like what I am experiencing.
Looking at the diagram that little vacuum hose nipple was plugged into the SAI pump, I am going to hook it up to the bottom of the planum and see what happens.
Will this solve the issue, don’t know and I am not getting my hopes but it appears not to be setup like it should be, sooo…
Sure hope you found your issue!
Fingers crossed!!!!!
Did map sensor adjustment work?
Tank5
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- #340
I was able to hook the sensor that is in place under the planum to the planum but it did not change the engine response, FTs or the atmospheric reading. It is possible the sensor is damaged, so I am waiting on a new oem replacement to arrive and a filter to protect the sensor. When the new parts arrive I will get them installed and know for sure whether it changes anything.
