Recent Rebuild Poor MPG
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84 yota dude (03-23-2020)
#22
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Thread Starter
Sweet, thanks.
I will note that we used the 1989 22re fuel pressure regulator and fuel rail which does not have the fuel pressure damper found on the '87 rail.
I sourced some '87 plug type injectors which were rebuilt. I wanted to send my originals in to witch hunter but we wanted to setup our rebuilt engine for a plug and play so we could drop it in.
I do not think any injectors are stuck open because the oil does not smell like gas and the engine runs great. However, I still need to check the plugs.
I will note that we used the 1989 22re fuel pressure regulator and fuel rail which does not have the fuel pressure damper found on the '87 rail.
I sourced some '87 plug type injectors which were rebuilt. I wanted to send my originals in to witch hunter but we wanted to setup our rebuilt engine for a plug and play so we could drop it in.
I do not think any injectors are stuck open because the oil does not smell like gas and the engine runs great. However, I still need to check the plugs.
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84 yota dude (03-23-2020)
#24
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I've read about witch hunter on yotatech but I didn't know that. Good to know!
#25
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There are zero, hear it again, ZERO adjustable or replaceable parts to your fuel injectors. Any where you send it all they are going to be able to do is clean it, change the filter and flow test it. There is nothing to warranty. They didn't do anything you can not do at home..
..
The fuel pressure regulator difference (rail pressure at the injector) you guys are looking at is well within the 15% of the ECU's adjustment threshold before it throws a code.
If you want to disprove this your going to need to scope and log the injector trigger pulses and oxygen sensor..
The oxygen sensor flipping between rich and lean tells you that the system is working as intended.
..
You should start looking at things like, wheel bearing preload, brake drag, and other such sources that will eat HP..
..
PS from what I recall the fuel pressure regulator has the same threads in all of these so you can just swap back in the 87 version. I'd be looking at things like the "trust" of the IAT, VS, and VTA and then the mechanical bits like the bearings and brakes.
..
The fuel pressure regulator difference (rail pressure at the injector) you guys are looking at is well within the 15% of the ECU's adjustment threshold before it throws a code.
If you want to disprove this your going to need to scope and log the injector trigger pulses and oxygen sensor..
The oxygen sensor flipping between rich and lean tells you that the system is working as intended.
..
You should start looking at things like, wheel bearing preload, brake drag, and other such sources that will eat HP..
..
PS from what I recall the fuel pressure regulator has the same threads in all of these so you can just swap back in the 87 version. I'd be looking at things like the "trust" of the IAT, VS, and VTA and then the mechanical bits like the bearings and brakes.
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RASALIBRE (03-24-2020)
#26
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Thread Starter
Ok.
I know for certain that there is nothing mechanical causing poor efficiency. Because nothing was touched on the drivetrain during the engine swap and the truck got 20 mpg last summer on a 1000 mile road trip with the original engine.
The tail pipe is black and the engine is definitely running rich. It would fail an emissions test.
IAT=inlet air temp? How is this checked without cutting open the AFM?
What is VS and VTA?
I know for certain that there is nothing mechanical causing poor efficiency. Because nothing was touched on the drivetrain during the engine swap and the truck got 20 mpg last summer on a 1000 mile road trip with the original engine.
The tail pipe is black and the engine is definitely running rich. It would fail an emissions test.
IAT=inlet air temp? How is this checked without cutting open the AFM?
What is VS and VTA?
#27
Registered User
Have ya done that compression check yet?
Compression/leak down test one or both needs to be done.
Again, I wouldn’t assume anything until tested and verified functional.
Compression/leak down test one or both needs to be done.
Again, I wouldn’t assume anything until tested and verified functional.
#28
Registered User
Your sensor signal is switching back and forth between rich and lean? This tells you it is in fact running in closed loop. This means your fuel delivered is calculated based on VS (load from vafm), VTA (throttle angle from tps).
Make sure those are giving nice clean and smooth signal levels by checking the resistance or voltage as they sweep from open to closed.
Make sure those are giving nice clean and smooth signal levels by checking the resistance or voltage as they sweep from open to closed.
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84 yota dude (03-25-2020)
#29
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Thread Starter
Thanks.
I have not done a compression test, have been feeling sick the past week. Nothing serious thankfully.
How is the inlet air temp sensor tested without hacking into the afm?
I have not done a compression test, have been feeling sick the past week. Nothing serious thankfully.
How is the inlet air temp sensor tested without hacking into the afm?
#30
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iTrader: (-1)
Do that cylinder leak test, you need to know that the valves and such are working as they should.
Check your drive line (tires, wheel bearings, brakes, ujoints etc) regardless of what you think it's state of functionality. Things happen when vehicles sit idle.
Unless your 20mpg trip and 13mpg trip were over the same roads in the same wind at the same speed it's not a fair comparison.. I get vastly different milage driving out of Denver compared to driving into Denver for example.
PS. Might be worth changing the o² sensor out for a clean one. You've verified the ECU is seeing a rich lean switch, so we know it's working but we don't know that it's not skewed due to buildup on the element or external port.
Last edited by Co_94_PU; 03-26-2020 at 08:42 AM.
#31
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#32
Registered User
Thread Starter
Does the FSM outline the AFM temp sensor test?
Update:
I tested the voltage of the throttle plate at the ECU and according to the '87 FSM the first reading (IDL-E2) for open is 4-10v. Meter read 11.75v. However, when looking at the '88 FSM for the same measurement the range is 8-14v. I should note the FSM specifies "open" not "fully open" for the IDL-E2 check. I had the throttle plate fully open. Which can explain why the voltage is possibly higher. In fact Toyota might have noted this and made an edit for the '88 FSM. However, I do understand the 22re electrical systems vary by year. I am going to test again with the throttle plate not fully open.
Second, throttle plate fully open (VTA-E2) range should be 4-5v, meter read 3.8v.
I checked the voltage for the AFM closed and it checked out. However, the manual notes to check the AFM with the "measuring plate fully open" with the ignition on.
My question is as soon as I moved the measuring plate, I could hear the injectors spraying fuel, this is normal correct? Why would the test be completed if fuel is dumping into the engine? Engine was obviously not running.
I did not complete the test because I did not want to dump fuel into the engine.
Another note, the intake smelled like raw gas. I did not see the cold start injector leaking when looking inside.
I will make a table of my measurements so it is easier to understand.
Update:
I tested the voltage of the throttle plate at the ECU and according to the '87 FSM the first reading (IDL-E2) for open is 4-10v. Meter read 11.75v. However, when looking at the '88 FSM for the same measurement the range is 8-14v. I should note the FSM specifies "open" not "fully open" for the IDL-E2 check. I had the throttle plate fully open. Which can explain why the voltage is possibly higher. In fact Toyota might have noted this and made an edit for the '88 FSM. However, I do understand the 22re electrical systems vary by year. I am going to test again with the throttle plate not fully open.
Second, throttle plate fully open (VTA-E2) range should be 4-5v, meter read 3.8v.
I checked the voltage for the AFM closed and it checked out. However, the manual notes to check the AFM with the "measuring plate fully open" with the ignition on.
My question is as soon as I moved the measuring plate, I could hear the injectors spraying fuel, this is normal correct? Why would the test be completed if fuel is dumping into the engine? Engine was obviously not running.
I did not complete the test because I did not want to dump fuel into the engine.
Another note, the intake smelled like raw gas. I did not see the cold start injector leaking when looking inside.
I will make a table of my measurements so it is easier to understand.
#33
Registered User
iTrader: (-1)
When you open the vane in the VAFM the fuel pump turns on. Sound like you've found out you have injectors leaking. To confirm this, and identify which injectors, you'll have to remove the upper intake then put slips of paper down the intake runners and run the fuel pump. You can confirm its an injector mechanical problem and not an electrical issue by unplugging the ECU, injector resistor, or at the injectors. I would start with the ECU, which removes the ground path, this confirms it's not a CPU problem with a transistor. If they are still open maybe it's conducting on the #10/#20 wire which runs from the ground side of the injectors to the ECU, so unplug the injectors or the resistor which will cut all power and isolate it to mechanical or electrical.
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84 yota dude (04-06-2020),
old87yota (04-03-2020)
#34
Registered User
Thread Starter
Ok. Thanks for the test info.
I am still confused about the fuel injector noise. Why would they not spray when the ignition is in the ON position?
You're saying that possibly one or more of these injectors is open? Correct?
I am still confused about the fuel injector noise. Why would they not spray when the ignition is in the ON position?
You're saying that possibly one or more of these injectors is open? Correct?
#35
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iTrader: (-1)
"Why would they not be spraying?" Because they aren't supposed to open unless they have power and are commanded to by the ECU (supplied ground).
#36
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Thread Starter
Ok. That makes sense. Thank you.
#37
Registered User
Thread Starter
Update: fuel issue and high idle at cold start solved!!
Had my original injectors serviced by mrinjector in Idaho. Would definitely recommend this business. Bill, the owner, did an excellent job and provided documentation (flow rate, leak test) unlike the injectors I bought last year.
When we pulled the upper intake there was a puddle of fuel in each intake runner. Do not think that is normal. Hard to believe all injectors were leaking..
Highway mpg now up to 22.5mpg!
Also, now there is the high idle, around 1200rpm, at cold start. Ended up buying a new IACV. Bought a new one as a reference to see what factory setting was at, but decided to keep it as there is obviously no corrosion on the coolant pipes compared to old one.
Out on the test drive. Love this thing!
Fuel in lower intake runners.
Natural habitat
Had my original injectors serviced by mrinjector in Idaho. Would definitely recommend this business. Bill, the owner, did an excellent job and provided documentation (flow rate, leak test) unlike the injectors I bought last year.
When we pulled the upper intake there was a puddle of fuel in each intake runner. Do not think that is normal. Hard to believe all injectors were leaking..
Highway mpg now up to 22.5mpg!
Also, now there is the high idle, around 1200rpm, at cold start. Ended up buying a new IACV. Bought a new one as a reference to see what factory setting was at, but decided to keep it as there is obviously no corrosion on the coolant pipes compared to old one.
Out on the test drive. Love this thing!
Fuel in lower intake runners.
Natural habitat
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84 yota dude (06-05-2020)
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84 yota dude (06-09-2020)
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