87tonkatoy

Alright so I have an 87 four runner w/22re. I have done so much to the engine and yet still battle with it running rich!!!

Heres what ive done to motor:

Head Gasket/Head Bolts
Valve Seals
new timing chain cover
new exhaust manifold
new TPS
new Denso O2 sensor
Injectors rebuilt and flow tested by Witch Hunter
tapped fuel rail and installed fuel pressure guage
new fuel pump
new fuel filter
new gaskets all over
new pcv valve
new exhaust muffler & pipe.......
new cap rotor wires plugs


Heres what Ive checked.....

TPS seems adjusted properly though it was tough to get all parameters to work at some time...

Water temp sensor checks out to FSM spec when cold(50F) and ran engine till hot and checked again... (170F?).

AFM checks out including air temp circuit resistance.

cold start system checks out and no difference when plug is pulled to cold start injector.....

timed with jumper in to 5BTDC.

So the engine now starts up great and sounds nice for the most part. But its visibly blowing out black smoke. Its much better from when I started but just wont run right!! Its also missing around 2000 to 3000 RPM.

Any Ideas?????????

myyota

Have you tried checking the ignition system, the pick up coil the igniter and coil ?, what about the AFM, does it look like its been opened up and adjusted ?, im just throwing out ideas, it seems like you have covered just about everything.

87tonkatoy

need to check the air gap on pick up in distributor again.... and the ignitor seems to function not sure how to check it without replacing with known good unit.... whats the test for coil? and I opened up the afm and it looks prety good there may be a tiny little bit of wear on the contact strips but only in very small amount of track.... might affect that spot but shouldnt affect while idle..... i dont think anyways...

I doubt it was opened before but who knows.... i thought about adjusting it more lean but seems like would be a band aid on bigger problem????

what all controls mixture? mind you it seems the same when cold and when warm.....

myyota

what all controls mixture? mind you it seems the same when cold and when warm.....[/QUOTE]

The things that i can think of that control air fuel mixture are, the 02 sensor, the TPS, and the computer. I just thought of something else, the thermostat. The stock thermostat is 195 degrees, if you have a lower temp thermostat than stock the engine might not be getting hot enough to go into closed loop.

tim a.

Fuel pressure regulator.

87tonkatoy

already replaced pressure regulator... (forgot to put in first post) so whole fuel system has been gone through...... not sure about thermostat i might just replace it anyhow. But even before it goes into closed loop it seems way too rich. I know during warm up there is alot more ar play than when in closed loop..... I read somewhere you can unplug water temp sensore and jump in a resistor of approriate ohms and fool comp into going into closed loop is that really possible?

myyota

No, you can`t do that. your thinking of the temp sensor for the egr, when you delete it those with a temp sensor use a resister to fool the computer.

myyota

Just for the heck of it, have you tried pulling the vacuum line off of the egr to see if that makes a difference ?.

Thelast83inNJ

As RAZED suggested above, check coolant temp sensor. Maybe it's telling the ECM it's 10 degrees all the time. My suggestion is unplug or isolate the evap canister maybe it's full of fuel.

87tonkatoy

Interesting. So as far as connection to water temp sensor it is good. I actually removed engine wire harness took inside opened up and inspected all splices, tested continuty on all circuits and retaped whole thing. It also threw a code 4 (water temp sensor circuit) when i unplugged it while running so circuit must be ok....

I ohm tested it at about 50 degrees F truck had been off all week so was good base line. was right in line with graph from FSM. Then warmed up engine and ohm reading seemed to be in spec though Im not sure exact temp of engine the ohm reading seemed to be where about it should be according to FSM for 170-190 or so. Its a curved graph with three lines so there is a bit of a window there.

Fuel pressure seems maybe a little high it was around 40 P.S.I on idle and moves around from bout 32 to 42 while reving up and down.... I need to go record more exact. I have also read that you can remove pulsation damper (replace with banjo bolt from where?) in fact toyota stopped using it on there fuel systems all together?

I checked the charcoal canister again to FSM spec.... and seems to do as fsm says. If I isolate it would I plug the purge line to intake all together? and should just open gas tank vent line?


Now as for the EGR...... so first of all the vacuum to the egr pipe was completly clogged when I started this project I cleared i and all other lines seem ok. Note when the vehicle was parked about 8 years ago it had just passed emissions. It had been drivin only about 5000 miles since emmisions test and then parked for eight years. So it had to pass with that line clogged i can ony imagine. Perhaps I opened a problem in fixing that line. Im still trying to fully understand the egr system. Alot of rubber compnents were toast from sitting but I have been systematically replacing them as I find them.

Thank you guys so much for input I will be a 22re master by the time Im done here (a broke 22re master that is)

tim a.

Ok you replaced regulator.Does it work?You have answered your own question.Fuel pressure is high,and i am running rich.Survey says....fuel control.Please put a vacuum tester on your FPR and and give it a little squeeze.I am betting fuel pressure comes down.I am not sure why anyone thinks the EGR system is going to make the engine run richer,I just cant connect those dots.All the EGR does is inject an inert gas to cool combustion chamber during high load situations to minimize nox formation.No fuel control there.Cant be 02 if you say its rich in cold loop.Thermostat?...not likely.Check your regulator and corresponding vac lines.Perhaps there is an issue with your pressure gauge instalation?

87tonkatoy

I will check the fuel pressure as soon a i have a chance to get out and work on it.... does vacuum to the regulator raise or lower pressure? and supposing the pressure was a little high would the o2 sensor account for that when in closed loop? the vacuum line goes from regulator to VFM thing which I tested and it functions as FSM says. then it goes to a little black three way (with other two capped) insert into manifold. have seen people on here talk about bypassing VFM all together and run vacuum straight to intake..... as for installation of fuel pressure guage (liquid filled) I drilled into rear end of fuel rail and tapped and installed a brass bushing then a brass 90 came up just high enough to see behing EGR. Looks real nice in there.

tim a.

vacuum pulls the regulator, lowering pressure.When you disconnect vac, regulator goes to highest pressure.Should be straight manifold vac,I will check mine to make sure.The o2 sensor will try to make adjustments,but you must realize this is a rudimentary f/i system.Its not as capable as obd 2.Put vac pump on regulator and put a little draw on it.I imagine your fuel pressure will go down,

87tonkatoy

havent checked anything yet but the thing the vacuum line goes through is a called VSV not VFM not sure where i got that from... to much to remember

greatskiiiier

how do you know its running rich? do you have a wideband on it? my truck smells like its running rich even when the wideband says 16:1 at idle

87tonkatoy

update..... I know its running rich from smell/black smoke..... consistant amount of black smoke through all rpms and a big puff when hit throttle hard..... it leaves black residue on the ground beneath tail pipe as well...... not head gasket no water or steam, rings may pass a little oil but that would be white right? and the thing passed emisions 8 years /5000 miles ago so I believe whatever is malfuntioning is due to time......

fuel pressure..... with fuel pump jumped and engine off 38psi.
running @idle 32-34psi.
reved up 34-38psi.
vacuum line pulled off regulator while running 38 psi.

i did not apply vacuum to regulator seperatly but it is reacting to manifold pressure.... now i just need to find if thats the proper pressure?

so any ideas now?????? could moving AFM gear one tooth towards lean help?

87tonkatoy

bump...

Hadmatt54

You are asking for ideas...You mentioned that the cold start injector is operating properly and you say that there is no difference when you disconnect the 12v from the cold start injector so that should also rule out if the start injector time switch is operating properly.
You don't have a heated O2 sensor so the ECU will ignore any return data from it until the engine is up to operating temperature, so that might be why you are seeing the rich condition at start up.
All the work that you have done I see no mention of the timing chain and gears. If your chain is slack you may not be holding the static timing and you might have some valve overlap, that could cause a rich condition.
Do you have any exhaust leaks? That can skew the O2 sensors ability to read the amount of oxygen in the exhaust, making the ECU unable to control a rich condition.
Are you running a header? Moving the O2 sensor farther away from it's stock location will also inhibit it's functioning ability.
What are you using for an air intake / cleaner? Your fuel might be right, but if you are not getting the proper amount of air to mix with it your air/fuel ratio will be off.
Do you have any leaks in the intake system where unmetered air can enter the intake system after the AFM? That will throw off your A/F ratio also.
Hope this leads to to the fix!

87tonkatoy

Exhaust is tight... brand new manifold (OEM replacment) all new studs & nuts. the cat had already been removed and a pipe welded in, the muffler was rotted out I put a pipe and muffer in myself all welded.......

intake seems good have a brand new FRAM air filter....

Interesting you mention timing chain. the reason I changed timing chain cover is because it was leaking water. when I pulled it off it was obvious that the timing chain had worn through the guides at some point and rubbed through into water chamber. someone had aluminum welded the hole which probably warped the cover so I replaced whole cover. There were guides installed so someone had replaced the guides at some point. when I pulled the oil pan the old guides were actually in there.... grrrr.... so previous owner did half a$$ job. I dont know if the chain or gears were replaced.... the tensioner seemed good. how can you tell if its slacked? it seem really really tight and I had to compress tensioner with long rod to get gear back on cam....

coule the valve adjustment do it? I adjusted them once cold but who knows......

Hadmatt54

With a single cam engine there is not the overlap possible that can occur in a dual cam setup, but if your chain is stretched or worn it can throw the valve timing off. Opening timing, valve duration or closing timing (cam and crank angle relationship in degrees) may change. A worn cam can change this relationship as well.
But before you go that route, I'd look at the pick-up (Ne) in the dist. You already said that you need to check the gap, but does it test ok according to the FSM? The 22re uses a VAST system to control spark advancement. The Ne signal is shaped by a control circuit in the igniter before it is sent to the ECU. The igniter also gives the ECU the IGT and IGF signals which the ECU uses in timing changes as well. There are some tests you can do on the igniter according to the FSM, but it may be easier to find another igniter and try that. There should be a ton of them around.