Mechanic's stumped.....

[Seth_O]

I have a buddy with a late-model 2wd toyota minitruck (22RE.) The truck runs roughly at idle, and smooths out under acceleration or when 25mph+ and has no noticeable loss of power.

However, it's failing nox at 25+; but passing at idle and 15mph (when it's running rough.)

He's done a full tune-up (new cap, coil and wires,) adjusted the timing and valves, checked the EGR, replaced the PCV, fuel filter and catalytic converter and checked for vacuum leaks.

My wrenching vehicle of choice is a '69 FJ40, so I am a little out of my league with emissions and fuel injection.

The local toyota mechanic is stumped, anyone have any ideas? It's his DD, so he's stuck until he can get it to pass emissions....

 

[cruiser88]

How did he check the EGR and did he check the idle air contol valve?

What about codes?

 

[Seth_O]

EGR check was a visual I believe, and the fact that it doesn't kill the engine when it's installed.

It's not throwing off any codes. I don't know about the idle air control valve - will look into it.

Any other thoughts folks?

 

[cruiser88]

Clean the intake and that EGR. You cannot just look at a EGR valve and say....its ok.

 

[Mace]

vac issues IMHO

 

[cruiser88]

I thought about that buttttt I just assumed the tech would have checked that......lol....you stalking me tonight

vac issues IMHO

 

[cruiser88]

oh crap....I just remembered .......I had a temp sensor do the same . Yes it was on my 62 but its worth a shot. The sensor was not bad but the wire/plug was. The blasted thing would run rich all the time because the computer thought it was(the engine) was cold.....and it did not throw a code

Sorry I dont have the fsm you would need but one of the guros in the am would help out

 

[Hank]

Get a new mechanic.


Need to see PIDS @ Idle and at elevated RPM where it passes. Compare related fuel trims and an astute technician will see the issue.

 

[Seth_O]

Good stuff guys, tks.

Cruiser88: how do I check the EGR and idle air control valve? Sorry if it's a no-brainer, but again - emissions & injection stuff is all new to me. If it were a carb I would have assumed a gummed up idle jet. Will also check the temp sensor.

Mace: checked for vaccum leaks with no finds, but will check again - tks.

Hank: PIDS? Not familiar with that one.

Originally the nox tested ~3500 at 15mph (vs 911ppm acceptable.) After all the work was done it brought it down to 1500ppm - much better but still too high to pass.

 

[Hank]

Each piece of information in a "mode 6" scan of live information is a PID (Parameter IDentification). Such as: Fuel trims, misfires, NO2 readings, baro pressures, etc.

 

[Seth_O]

I have a buddy with a late-model 2wd toyota minitruck (22RE.) The truck runs roughly at idle, and smooths out under acceleration or when 25mph+ and has no noticeable loss of power.

However, it's failing nox at 25+; but passing at idle and 15mph (when it's running rough.)

He's done a full tune-up (new cap, coil and wires,) adjusted the timing and valves, checked the EGR, replaced the PCV, fuel filter and catalytic converter and checked for vacuum leaks.

My wrenching vehicle of choice is a '69 FJ40, so I am a little out of my league with emissions and fuel injection.

The local toyota mechanic is stumped, anyone have any ideas? It's his DD, so he's stuck until he can get it to pass emissions....

Just to wrap this issue up - my buddy finally got his truck fixed. Ultimately the dealer was able to locate the problem as a bad Mass Air Flow Filter.

I wasn't aware the MAF had it's own filter (again no familiarity with fuel injection) so not sure if the owner misheard and it was a bad MAF sensor. $280 for a rebuilt unit + free labor from the shop that was originally unable to hunt down the issue and the truck runs like new and cleared emissions no problem.