drranch

I have a 94' 22RE , 195k, that seems to be sporatically dumping fuel into the engine, causing the motor to load up and caugh black smoke. It does it repeatedly when the operating temperature is about half way up to normal, once at normal operating temperature it will act up whenever it feels like for however long it feels like. Leads me to be something electrical. Never has the check engine light came on. Engine will idle rough and have next to no power till about 4000 rpm. Only way to get up that high is to pump the gas pedal. If I put the padal to the floor it is almost like you turned the key off. weather seems to play no role on this. some days it is perfectly fine others it is just a pain. City driving seems to make it act up more than open road. Unplugging air flow sensor seems to cause same symptoms only engine dies, however sensor test out good as specs in my Haynes Manual. EGR valve has been taken off and cleaned. It is free in working order

complete tune up about 8000 miles ago, timing chain service w/ water and oil pump about 7000 miles ago, Has been doing this for about 4000 miles, just changed the fuel filter.

Best lead I have now is a bad injector. I am having a hard time believing that being that all 4 plugs are black and covered with carbon, unless it's the cold start injector. Is there any way to test the vacuum advance?

Any help appreciated, about fed up to the point of trading it off. Especially after replacing 20' of brake line last night.

drranch

Also no CEL untill it loads up to the point it dies.

drranch

I have drove with the cold start injector electrically disconnected and still same symptoms. Drove with O2 sensor disconnected, same symptoms. Drove with TPS disconnected, same symptoms. Timing was set when timing chain service was done. I need to get that timing light back and try checking my timing when this thing is acting up.

My99

Take your AFM off and test the resistance compared to the factory manual recommendations. This is what was causing me issues (although it was ALL the time instead of off/on) a while back.

just a 22re

what about the coolant temp sencer not for the gauge but for the ecu maybe its bad?

air filter very dirty or cloged?


it seams that you have fuel and spark so it will be in the air flow perhaps you have a clog somewhere in the air intake check the box over really good cause the air filter maybe brand new and the box itself has alot of dirt in it getting sucked up to the airfilter so i would look over the air intake itself

drranch

AFM tested ok to specs in my haynes manual however the air temperature tested about 20 degrees high which I contributed to my truck being black and setting out in the sun. Air filter is fairly new but I will check air system for obstructions. Read the test procedure for checking coolant temperature sensor, will do that when I get a chance soon. With how sporatic this is (only lasting 10-20 seconds each time) if the cause will test ok unless I can catch it when I am having issues.

iamsuperbleeder

have you tryed to pull the codes yet? that would be my first step...

drranch

Will there be a code if the CEL does not come on? and if so what is the procedure of pulling the codes?

My99

Yes, there can be a code stored without the light being on. Try this link:

http://www.off-road.com/toyota/tech/codes/index.html

iamsuperbleeder

Well, you mentioned "no CEL untill it loads up to the point it dies", so reading that and assuming it did come on, the codes should be stored.

The diagnostic proceedure should be the same for my 91 as it is for you 94.

Attached to the fuse box under the hood, just behind the battery, there's a little port with "Diagnostic" or something similar (I can't remember for sure) stamped on it. Pop it open. You'll notice the lid portion has a layout of the pins in the diagnostic port. Using a small peice of wire (paperclips don't work many times because many have a plastic coating on them), jump teminals E1 and TE1 together. Now sit in the truck and get ready to count. Turn the key and watch the CEL flash. If it flashes constantly at about half a second incements, that's a normal code and means there are no codes stored. If it flashes a few times, pauses, then flashes some more, then there are codes stored and you need to take note of how many times it flashes. Decoding the flashes isn't that hard. If it flashes once, then pauses for a sec, then flashes 4 more times, then pauses for about twice as long, then that's a code 14. Basically, each flash is a number and each digit is separated by about a secong long pause. Each long pause is pretty much a break, and it will then either flash the same code again, or flash a different sequence if there is more than one code stored.



After typing all that, it may have just been easier to reffer you to the FSM...

drranch

Reads a code 41-TPS which as I noted above I have drove with TPS disconnected and had same symptoms. I believe I will try clearing codes, run for a while and pull the codes again later.

iamsuperbleeder

well, TPS may be bad, or just out of adjustment if you've mess with it and had it off in the past

drranch

only disconnected TPS electrically. mechanicall it is un-tampered. still has paint mark from original assembly indicating it is in the original location. I wen't off and left my good DMM at work over the weekend so I am going to attempt testing the TPS now with my back-up DMM

drranch

ok, TPS test to specs and e2-IDL opens at about .032" - .033" on the throtle stop screw. Any ideas on testing the coolant temp sensor without a thermometer?

drranch

For $30.00 I may just replace the coolant temp. sensor to rule that out. Odd the truck predictably acts up in a mid temp range while the motor is warming up. have to get this thing running right so I can get rid of it. While replacing brake lines I noticed 4 rather large holes in the frame. Already had to re-attatch a spring hanger and strengthen the frame last year.

abecedarian

have you pulled the plugs? if so, how do they look?
have you verified your timing is correct?

drranch

timing was set when I did the timing chain service. It was about two months later when this problem statred. All four plugs are black, covered with carbon.

abecedarian

when you checked the timing, you shorted the appropriate terminals in the diagnostic connector behind the battery with the engine running correct? when you shorted them, then engine idle speed dropped correct? what is the timing set to?

when was the last valve adjustment?

have you pulled the cold start injector out of the manifold and verified it's not leaking?

it's possible the O2 is starting to go out and sending slightly wrong signals to the ECU- my experience with the few I've had go bad is that don't go bad suddenly but rather take their time and slowly fade away.

drranch

yeah, engine did pull down when terminals were shorted on the diagnostics plug. Timing was set to 5 btdc as shown on tag under the hood. Can't tell you when the last valve adjustment was, I have had the truck since 120k. It's first timing service was done at the dealership with about 93k on it. Don't know if they set the valves then or not.

For the O2 sensor I have ran with it unpluged and it had no effects on the motor other than making the CEL come on. I would assume with the O2 unpluged the ECU would switch to some default setting for that input.

I have not pulled the cold start injector out to see if it's leaking; I assume run it up to temperature first then pull the injector out?

abecedarian

valve adjustment is important to the engine. improperly adjusted valves will affect the engine performance.
not having the O2 sensor connected will force the ECU into a fail-safe mode and will cause the engine to run rich. of note, a failing O2 sensor may not trigger a fault with the ECU until it has actually grossly gone bad so there is a range of operation that the O2 will appear to work in but in actuality it is bad.
checking the cold start injector should only require pulling it from the manifold and energizing the fuel pump by either turning the key on without starting the engine or jumpering the fuel pump so that it runs.