94 Fzj-80 Failed Emissions

[simps80]

That maf helped.
Unfortunately not enough.
It would be nice too see a graph of reading to rpm. If its rich throughout or not.
That high of co plus high hc but ok NOx is rich fuel mix prob from 02 failure. Or maf malfunction..but don't think so cause that was drastic change last night down to 50

Might be able to get it passed with no air filter and pull all the junk off the front....but i bet its o2 sensor

 

[Snowrun]

I ordered O2 sensors,PCV(with grommet), and a PAIR valve today. Should be in next week.
It looks like the MAF had a pretty dramatic effect of the low speed portion of the test in regards to CO.
It also threw another CEL 25 as a result of the test. I think it is interesting that only the emissions test seems to get the car to throw a code.
BTW sorry for the sideways pic. Not sure why it keeps getting turned when I upload it.

 

[treerootCO]

Found this on the internets

Most often a faulty TPS will cause high CO, as an engine's ECU always prefers to send more fuel rather then less, in an effort to avoid a lean fuel mixture and subsequently higher engine temperatures.

View attachment throttle.pdf

89452-22090
Europe, N. America 01/1990-12/1997 TOYOTA LAND CRUISER FJ80,FZJ80 84-04: ELECTRONIC FUEL INJECTION SYSTEM

22RE??? part number
Part 89452-14050 (SENSOR, THROTTLE POSITION (FOR E.F.I.))
Europe, N. America 01/1990-12/1997 TOYOTA LAND CRUISER FJ80,FZJ80 84-04: ELECTRONIC FUEL INJECTION SYSTEM

about $75

 

[Blindranger]

Found this on the internets

Most often a faulty TPS will cause high CO, as an engine's ECU always prefers to send more fuel rather then less, in an effort to avoid a lean fuel mixture and subsequently higher engine temperatures.

View attachment throttle.pdf

Part 89452-14050 (SENSOR, THROTTLE POSITION (FOR E.F.I.))
Europe, N. America 01/1990-12/1997 TOYOTA LAND CRUISER FJ80,FZJ80 84-04: ELECTRONIC FUEL INJECTION SYSTEM

about $75

Thank you Treeroot! I have been plagued by high CO, but within limits for everything else, this sounds like it might be a solution.

 

[bruce285]

When I get it back on. Putting new valve cover gasket and plug seals, replacing VSV and all vac hoses today. Still soaking the plenum and cleaning the TB. I'll include the EPA Inspection report.

 

[Snowrun]

Found this on the internets

Most often a faulty TPS will cause high CO, as an engine's ECU always prefers to send more fuel rather then less, in an effort to avoid a lean fuel mixture and subsequently higher engine temperatures.

View attachment throttle.pdf

Part 89452-14050 (SENSOR, THROTTLE POSITION (FOR E.F.I.))
Europe, N. America 01/1990-12/1997 TOYOTA LAND CRUISER FJ80,FZJ80 84-04: ELECTRONIC FUEL INJECTION SYSTEM

about $75

For my 94 It looks like the part number is 89452-22090. Just ordered one of those as well.

 

[treerootCO]

89452-22090
Europe, N. America 01/1990-12/1997 TOYOTA LAND CRUISER FJ80,FZJ80 84-04: ELECTRONIC FUEL INJECTION SYSTEM

 

[davework]

Just to add another possibility, I chased high CO all over the place for about 6mos after I rebuilt the engine in my 94. It had new everything except cats. The last thing I tried before replacing the cats was a new fuel pressure regulator. Instant pass. It's a relatively cheap part, and easy to swap. It doesn't come up often in emissions discussions, but I was out of options. Wish I had tried it sooner.

 

[LARGEONE]

Just to add another possibility, I chased high CO all over the place for about 6mos after I rebuilt the engine in my 94. It had new everything except cats. The last thing I tried before replacing the cats was a new fuel pressure regulator. Instant pass. It's a relatively cheap part, and easy to swap. It doesn't come up often in emissions discussions, but I was out of options. Wish I had tried it sooner.

I changed out the fuel pressure regulator on our manny's (not a typo, yes our nanny is a dude) Isuzu to bring his emissions into spec as well. This is a cheap part and might be worth doing.

 

[Snowrun]

Just to add another possibility, I chased high CO all over the place for about 6mos after I rebuilt the engine in my 94. It had new everything except cats. The last thing I tried before replacing the cats was a new fuel pressure regulator. Instant pass. It's a relatively cheap part, and easy to swap. It doesn't come up often in emissions discussions, but I was out of options. Wish I had tried it sooner.

I will add it to my parts list.

 

[treerootCO]

Scariest Jack O' Lantern ever!

 

[treerootCO]

Shotgun troubleshooting!

 

[treerootCO]

Didn't quite get done. The inside O2 sensor we got from Stevenson is defective. We plug the new one in and throw a code 28. If we plug in the old one, the code clears. It took a week to get this set so I'm not sure what to do.

 

[rover67]

I know you're a toyota guy but why not throw in a generic for the mean time?

 

[treerootCO]

It throws a code 28 with the old, the new, and the known good (the RH O2 can plug into either so we tried all three) now so we are thinking the wiring is suspect. We grounded the O2 sensor and John is going to check resistance through the plug and continuity as far up the harness as he can. We can plug the new RH O2 into the LH plug to prove the O2s are good if needed. John says the wires are not long enough to do that with the RH O2 installed.

Found a better way to clear the codes as well. With the EFI fuse pulled, you turn the key to the on position and wait for the CEL to go out. The key on drains the capacitor and forces the memory to be lost. Just pulling the EFI doesn't always clear the code.

Verified the wiring is correct and matches the harness. John might pull the wires on the ECU just to rule out a bad connection there. Not likely but easy enough to rule out.

O2 wire Color Code Mr. T - OE
Blue = Signal wire
White = Heater wire 1 (non polarity)
Brown = Heater wire 2 (non polarity)
Grey = Aux Ground

 

[rover67]

Interesting, sounds like it must be the wiring. does the aux ground go all the way back to the ECU?

 

[treerootCO]

John is dropping the 80 off at Slee tomorrow to have the harness rewired before he puts a 50cal round through the block.

 

[jps8460]

Be sure to load it up with tannerite first, you don't want it to limp away.

 

[Snowrun]

It passed!!!
I am extremely thankful for Joe at Slee. He found that the previous owner had hacked the wiring to the O2 sensors. He fixed it and resolved all of the codes.

 

[wesintl]

yay