1994 PU 22RE running lean

[BG88]

 Hello to everyone, I'm new here so still trying to figure this out.

Truck info.. 1994 Toyota PU regular cab, manual 5 speed, 4.10 gears 31x10.5 tires, stock suspension.

What's been done so far..
Rebuilt engine has around 10k on it, compression as of now  is 185 psi on all cylinders.
Cyl. Head, valve train, cam already assembled from 22RE performance.
Dual row timing chain kit from LCE
Upper and lower intake with big bore throttle body bored to match from 22RE performance (TPS already installed)
Fuel.. new tank, OEM pump and filter, injectors from 22RE Performance, cleaned out lines and fuel rail.
Ignition.. new OEM distributor, plugs, wires, igniter, coil is from advance.
Intake.. Cold air intake from LCE, but have swapped back to OEM. No difference in performance.
Misc.. new OEM PCV valve and all hoses and lines associated with vacuum, brake booster, both coolant temp sensors, denso 02, negative battery cable, alternator.
Exhaust.. LCE header, header back 2.25 from LCE, no converter. Have swapped muffler out to quieter one but no change in performance.
EGR delete, code 71 EGR system failed is present.
New radiator with engine build.

So my conclusion is that my truck is running lean. I feel this way bc the original engine seemed to have more power and when towing pulled stronger. It only seems to have 1/4 to 1/3 of throttle response, after that just seems like all I'm doing is giving it to much air and bogs.

Truck history.. bought the truck 7yrs ago could tell it had been in the mud but didn't took horrible. Drove it for 3yrs before the timing chain broke. Wanted to rebuild it right and be problem free for many yrs to come I dug in replacing anything that potentially would come back on me.

Ordered a stage 2.5 fully blueprinted engine along with numerous parts from 22RE Performance. After install and cam break in I started down the road. The half mile or so down the road the truck ran amazing, pushed me back in the seat very nice. Turned around to go back to recheck everything hasn't ran that way since.

So I put around 500 miles on that engine when the coolant hose blew off under the throttle body. Believing that it did indeed run hot and needed repair I sent it back to 22re performance.

In the meantime I had another engine that I had built with parts from 22re performance in a card truck that had recently been T- boned I swapped in that engine. Which is still in it now. When that engine was carbed it ran better than it does now.

So now to my knowledge the only thing left that could be causing my lack of power/ lean concern is the AFM, engine harness or the ECU. I've opened the AFM and played with the gear felt on significant gain, cleaned returned to stock and resealed. I've opened my ECU for any corrosion, water damage, anything burnt, damaged pins or connectors. None found.

So back to the mud, engine harness as I've opened it has mud in it, mud under carpet, ECU had mud on it. Mud was even behind the dash on the instrument cluster. The reason I mention this is I think water damage is my problem but I can't find it and I hate guess work or throwing parts at something.

Any advice will be very much appreciated, and thanks to everyone in advance.

[gnob]

Sounds like you are guessing its lean.  Too much fuel will cause bog too.
You need to start by either getting a dmm on the o2 sensor or taking it to someone with a gas analyzer.
Based on what you said i would also be looking at fuel filters and verify that the chain didn't skip

[BG88]

Forgot to add that I have checked the TPS a few times, ohm out the AFM, tested good. And under full throttle sustained for a few miles the temperature gauge rises form 1/4 to 1/2.

[BG88]

I've also played with the timing, advanced till pinging was heard under loan the backed off a few degrees which was around 12-14 with the jumper installed, all the way back to 5 degrees retarded which ran worse. Currently at 8 degrees BTDC. When jumper is pulled timing goes to around 12. If you give it throttle the timing mark goes almost out of sight.

[BG88]

You need to start by either getting a dmm on the o2 sensor

So I hooked up to the Ox1 and Ox2 at the data link connector to monitor the voltage as gnob suggested. My DMM for DCV V settings that I used were 200m, 2 and 20. On 20 setting no voltage was seen. On 2 setting voltage was .000-.003. On 200m setting the voltage was 00.1-06.4 and was very sporadic.

If I'm doing it wrong or have any suggestions it would be very much appreciated.

[BG88]

I want to add that I am this weekend changing the fuel filter, plugs and wires.

[BG88]

Did the fuel filter and oil change. Test drove no difference. Checked O2 data ports again at 2 DCV V setting and .000-.003 was the same reading.

Also at idle the truck runs smooth a few seconds and then it sounds kinda like popcorn popping for a few seconds. It will do this at any RPM you hold it at.

[gnob]

With the voltage that low its showing lean.
Did you inspect the sensor wiring?
Are you certain there is no vacuum or exhaust leaks.

Next i recommend unplugged o2 sensor to see if you get change.  I would also sample sensor while unplugged from harness while truck is running

[Snowtoy]

The EGR delete with the stock ecu could be part of the running issue at non WOT running conditions, as well as not having a cat if you have two O2 sensors, one before and one after the cat.

I would check the rest of the intake system for leaks, from the AFM through the intake manifold, the accordion section is prone to leak with age as cracks develop along that section.
   
You said the current engine was from a carb'd truck, did you install the knock sensor on the engine?  Not getting a signal from the KS will also cause poor performance of the engine above 2000rpms.

If you have no leaks in the intake system, you might reinstall the egr system, along with the cat if you have the two O2 sensors system(not sure if it was just a CA smog setup or Fed '91-forward), just to eliminate them from being part of the problem.  The ecu was designed to function with them, not getting the input it expects to see, causes its own issues, and eliminating them as the cause will help to narrow down the possible cause.

One of the issues you may have with performance, is the exhaust system, "Exhaust.. LCE header, header back 2.25 from LCE, no converter. " makes for a high flowing set-up, great for upper rpms/WOT but not so much for regular driving conditions or for towing, as it reduces the velocity of the exhaust flow.  Adding the cat to the system and running a turbo muffler or a smaller exhaust tip or one that narrows toward the tip will help improve velocity at lower rpms and under normal driving conditions. 

The popping you are hearing in the exhaust, if not due to a leak, is likely from the change in the scavenging of exhaust gasses between the oem system and the headers/larger tube.

[BG88]

The EGR delete with the stock ecu could be part of the running issue at non WOT running conditions, as well as not having a cat if you have two O2 sensors, one before and one after the cat.

I would check the rest of the intake system for leaks, from the AFM through the intake manifold, the accordion section is prone to leak with age as cracks develop along that section.
   
You said the current engine was from a carb'd truck, did you install the knock sensor on the engine?  Not getting a signal from the KS will also cause poor performance of the engine above 2000rpms.

If you have no leaks in the intake system, you might reinstall the egr system, along with the cat if you have the two O2 sensors system(not sure if it was just a CA smog setup or Fed '91-forward), just to eliminate them from being part of the problem.  The ecu was designed to function with them, not getting the input it expects to see, causes its own issues, and eliminating them as the cause will help to narrow down the possible cause.

One of the issues you may have with performance, is the exhaust system, "Exhaust.. LCE header, header back 2.25 from LCE, no converter. " makes for a high flowing set-up, great for upper rpms/WOT but not so much for regular driving conditions or for towing, as it reduces the velocity of the exhaust flow.  Adding the cat to the system and running a turbo muffler or a smaller exhaust tip or one that narrows toward the tip will help improve velocity at lower rpms and under normal driving conditions. 

The popping you are hearing in the exhaust, if not due to a leak, is likely from the change in the scavenging of exhaust gasses between the oem system and the headers/larger tube.

With the voltage that low its showing lean.
Did you inspect the sensor wiring?
Are you certain there is no vacuum or exhaust leaks.

Next i recommend unplugged o2 sensor to see if you get change.  I would also sample sensor while unplugged from harness while truck is running

I checked a buddy's voltage on 93 model his voltage was 1.0-0.7 on the 200m setting. For the vacuum leak I've sprayed brake clean on anything pertaining to vacuum. And to verify I gave the air filter box a squirt and the engine revved up.

For the 02 wiring I removed the loow up to the transmission didn't see anything obvious. Also checked voltage w/ 02 unplugged showed 200m 0.0-0.3, same after I plugged it back in also.

[BG88]

No exhaust leaks heard and no soot found anywhere. My yr model only has one 02 sensor and it's before the cat. Talking to the guys at LCE on of the Tech's recommended I put in a choker pipe to see if the back pressure had anything to do with it.

[BG88]

It also runs the same with the factory air box and the Cold air intake from LCE.

The knock sensor was transferred.

[BG88]

Would anyone have the wiring schematics for a 94 engine harness and ECU pinout chart?

[BG88]

Truck had code 21 (Open or short in heater circuit of heated oxygen sensor for 0.5 sec. or more) from being unplugged. Cleared code, hasn't came back on yet.

[BG88]

Replaced the spark plugs with NGK BPR5EY V-Power and NGK plug wires this wknd, no difference seen.

[Snowtoy]

What do the old plugs look like, should be able to tell if you are running rich or lean.

[BG88]

What do the old plugs look like, should be able to tell if you are running rich or lean.

Tried to upload a pic but couldn't get it small enough.
But they were white on one side and a little more brown on the other. The central electrodes were worn down a bit on the sides.

[Snowtoy]

How do they look compared to this?



If you use a program like VVCAP for screenshots, or host the pic, you can link the pic to the forum w/o needing to meet the forum max pic size.

[BG88]

https://ibb.co/D4mL2nv
https://ibb.co/318yQ3T
https://ibb.co/5LNbkJP

[Snowtoy]

So that others can see them all at once





How long have they been in?

[BG88]

Around 5-7K

[BG88]

Why would it have the half and half color change?

[Snowtoy]

Could be just due to age, not sure how long it takes the insulator to completely tan under normal conditions.  Looking at some of my old ones from my '91, nearly the entire insulator was tan, not sure on the mileage though, as the engine tends to log more hours running a year than miles.

Could also be indicative of running lean, Bestgen or Gnob will have a better idea what the plugs are showing, not sure if running lean after will actually clean the insulator up.

Might pull the injectors and test them, there is a how to video on youtube, it is cheap pretty simple to set-up. 

Do you still have the oem coil, might swap that in and see if it helps any, the Advance one might not be putting out the voltage necessary under load.

[BG88]

I still have it, I'll give it a try

[gnob]

Do you have another o2?
I really don't like seeing 0 volts there ever.


Those plugs look fine or lean.

Try this for shits and grins.
Run truck to temp and sample o2.  While testing, block/pinch the fuel return line. This should spike the sensor.  In a correctly working system, simply blocking the vacuum line to the fp reg should spike voltage.

[gnob]

Did you reinstall the brake booster check valve?

[BG88]

Do you have another o2?

I have my old o2.

Did you reinstall the brake booster check valve?

I didn't remove it when I did the brake booster

[BG88]

So I checked the voltage for the O2 at idle 00.0-00.4, then removed vacuum line from FPR rpms went up voltage stayed the same.

So for shits and grins I took the charcoal canister vacuum line off and hooked a intake line (with vacuum at idle) to it voltage went up 00.3-01.0, so let it run like that for a min the voltage started to drop. Removed fuel cap voltage went up a bit. Put fuel cap back on and the vacuum lines correctly and the voltage stayed 0.02-01.1

Went for a test drive (1 mile or so) drove about the same. Came back checked voltage again now it's  -00.5-00.3 WTF.

[BG88]

Alright so an update for the O2 testing, I hooked up my DMM wrong at the data link connector. I miss interpreted the 02 test.

The two pins to connect to is Ox1 and E1 to check for voltage.

I have a 4 wire 02 sensor ( two black, one blue, one white) to check the heater portion I disconnected the O2 and measured resistance of two black wires spec. being 5.1-6.3 ohms at 68°F mine was 6.2 ohms.

I then checked the oxygen sensing portion by voltage, I removed the 02 from exhaust, connected to the white and blue wire, voltage was .000 when I heated the sensor after it reached what would be operating temp voltage went up to 1.0 volt.

I then connected to data link connector Ox1 and E1 and heated the sensor and got the same results.

So now that I (as far as I know) have verified that my O2 sensor and wiring to the data link connector are working properly it time to go for a drive again and monitor the voltage, so the results listed above are all inconclusive.

P.S. the sensor creates its own voltage, you don't have to supply any voltage to get a reading. My battery was disconnected while I was testing.

[BG88]

So I've put about 20 miles on the truck now while monitoring the voltage.

At idle the voltage is .2-.8 volts transitioning smoothly

While driving in any gear around mid throttle voltage is .3-.7

In first through fourth gear while cruising the moment I hit full throttle voltage goes up to .960 volts and stays there

In fifth gear voltage only makes it up to .880 volts, I think this is due to the rpms just not getting as high.

As far as my temp goes there's this 10 mile stretch I run full throttle every day, my temp gauge would go from 1/4 to 1/2 or a bit over. Now it only makes it up to 1/3 or so but not 1/2. The only thing I changed was plugs, wires and found a piece of foam to fit btwn the radiator and radiator support.

The plugs were from the original carb set up and may have been a hotter plug, not sure, someone correct me if I'm wrong.