Running rich and poor acceleration - running like crap
#22
LOL! Adjusting the idle screw is not going to make a vehicle not OEM. The ability to make fine-tune adjustments are absolutely necessary for any mass produced vehicle. Do you really think they can stamp out thousands of throttle bodies that idle exactly the same without any fine-tune adjustments?
I realize that we are talking about Toyotas, but most motorcycles and ATVs can be adjusted to run much better by adjusting the air/fuel screws differently than how they came stock. Manufacturers (Toyota included I would imagine) have to pass certain EPA specs. A common way of doing that is by making the motor run slightly lean at a certain RPM. It gets it to pass EPA spec, but is not optimal for smooth running or throttle response.
I realize that we are talking about Toyotas, but most motorcycles and ATVs can be adjusted to run much better by adjusting the air/fuel screws differently than how they came stock. Manufacturers (Toyota included I would imagine) have to pass certain EPA specs. A common way of doing that is by making the motor run slightly lean at a certain RPM. It gets it to pass EPA spec, but is not optimal for smooth running or throttle response.
Bottom line Is theres still and issue and its not just a matter of adjusting a screw and going unless they have been adjust before and are wrong? Timing somewhere between 0*-5* and idle 750-850 then theres another issue realting sensers. Check EGR unplugg and see if it helps? Vac leaks? Intake hose? Got a vac gauge? Check manifold vac and let us know the movement of the needle and how. I need to quit typing now.....................
#23
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Being as the O2 is directly related to fuel mixture...yes, it can cause a motor to run rich....
Heres a link to the FSM.... scroll down to the "Heated Oxygen sensor" section, and start testing.....
http://www.ncttora.com/fsm/1990-1995...es/repair.html
BTW.... a faulty O2 sensor will NOT always throw a code, the only time it will throw a code is of there is a short in the wire, or the "heater" goes out, or if you have a really lean/rich condition, that the ecu has run outta pre-programmed adjustments compensate for.
Last edited by Team420; 06-13-2010 at 07:14 AM.
#24
So I replaced both the AFM and o2 sensor and no improvment. Tonight I attempted to replace the coolant temp sensor, but I accidently removed the "cold start injector time switch". These two parts look quite similar... And I tell ya, this area of the engine is not easy to work in! As I was russling around trying to get a good position to remove the harness for the coolant temp sensor, (which I believe is the 4th sensor in the row?) I knocked out the line running to the 3rd sensor.
I know that sounds kind of confusing, so I will clarify. If you are facing the engine head on from the front of the vehicle - along the backwall thermostart housing area you have those 4 sensors ( I believe they are all sensors?) I'm not sure what the 1st one is - the 2nd is the cold start injector time switch - I dont know what the 3rd is - and the 4th I believe is the coolant temp sensor ?? Can someone please clarify?
So what I need to do now is replace the cold start injector time switch that i accidently removed, fix the wire that popped out of the harness on the 3rd sensor - and finally replace the coolant temp sensor.
I hope that all made sense - and just to be sure - the 4th one is the coolant temp sensor right?
I know that sounds kind of confusing, so I will clarify. If you are facing the engine head on from the front of the vehicle - along the backwall thermostart housing area you have those 4 sensors ( I believe they are all sensors?) I'm not sure what the 1st one is - the 2nd is the cold start injector time switch - I dont know what the 3rd is - and the 4th I believe is the coolant temp sensor ?? Can someone please clarify?
So what I need to do now is replace the cold start injector time switch that i accidently removed, fix the wire that popped out of the harness on the 3rd sensor - and finally replace the coolant temp sensor.
I hope that all made sense - and just to be sure - the 4th one is the coolant temp sensor right?
#25
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iTrader: (5)
I'm not good to you on this one....I have 3 in that general area. BVSV(vertical out of the top/front of intake), CSI to left and Coolant Temp Sensor on right.
Guys, aren't the CSI time switches brown in the 3.0, too, and the Coolant temp Green? I'm guessing he has more than mine in that location, and that they're obviously harder to get to than on my 22rec....
Hoping someone can throw a link to the Diagram you need, 4runner!
Guys, aren't the CSI time switches brown in the 3.0, too, and the Coolant temp Green? I'm guessing he has more than mine in that location, and that they're obviously harder to get to than on my 22rec....
Hoping someone can throw a link to the Diagram you need, 4runner!
#27
Registered User
So I replaced both the AFM and o2 sensor and no improvment. Tonight I attempted to replace the coolant temp sensor, but I accidently removed the "cold start injector time switch". These two parts look quite similar... And I tell ya, this area of the engine is not easy to work in! As I was russling around trying to get a good position to remove the harness for the coolant temp sensor, (which I believe is the 4th sensor in the row?) I knocked out the line running to the 3rd sensor.
I know that sounds kind of confusing, so I will clarify. If you are facing the engine head on from the front of the vehicle - along the backwall thermostart housing area you have those 4 sensors ( I believe they are all sensors?) I'm not sure what the 1st one is - the 2nd is the cold start injector time switch - I dont know what the 3rd is - and the 4th I believe is the coolant temp sensor ?? Can someone please clarify?
So what I need to do now is replace the cold start injector time switch that i accidently removed, fix the wire that popped out of the harness on the 3rd sensor - and finally replace the coolant temp sensor.
I hope that all made sense - and just to be sure - the 4th one is the coolant temp sensor right?
I know that sounds kind of confusing, so I will clarify. If you are facing the engine head on from the front of the vehicle - along the backwall thermostart housing area you have those 4 sensors ( I believe they are all sensors?) I'm not sure what the 1st one is - the 2nd is the cold start injector time switch - I dont know what the 3rd is - and the 4th I believe is the coolant temp sensor ?? Can someone please clarify?
So what I need to do now is replace the cold start injector time switch that i accidently removed, fix the wire that popped out of the harness on the 3rd sensor - and finally replace the coolant temp sensor.
I hope that all made sense - and just to be sure - the 4th one is the coolant temp sensor right?
#28
So I replaced the following and I still havent fully resolved my problem. AFM, o2 Sensor, coolant temp sensor and fuel pressure regulator. I am no longer getting the "popping" sound from the exhaust or the bucking while driving, but she is still running rich and very rough. It feels like she has half the power of what she normally does. I went ahead and dropped her off at my local shop to get checked out. I told them all the symptoms and what I have replaced already, they said it might be the fuel pump. They are going to check it out in the morning and give me a call...
#29
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iTrader: (5)
316, forgive me if I've skimmed right past it...but did you check the Fuel Pressure while replacing the FPR? I would think if you checked the Fuel Pressure you should be able to tell if the Fuel Pump is ok......Sorry, redundant for now, lol...I guess we'll see what he says by the afternoon.
Thook......does this sound like it may be the Knock Sensor to you? Wouldn't those symptoms be TOTALLY retarded timing, less power, maybe a rich condition because it's premature on the burn? Just asking...don't throw anything at me, k? lol.
Thook......does this sound like it may be the Knock Sensor to you? Wouldn't those symptoms be TOTALLY retarded timing, less power, maybe a rich condition because it's premature on the burn? Just asking...don't throw anything at me, k? lol.
#30
I never actually tested the fuel pressure. The Haynes manual says to "listen" to the regulator for a "pulsing" sound and if it is silent then replace. I put a tube up to it and listened and couldn't hear anything. So I decided to replace.
#31
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iTrader: (5)
Not sure about the tube, ....I just use a straight long pry bar, cup it near my ear and place it on the regulator and 'TICK-TICK-TICK-TICK-TICK'n away is good, nothing is bad. I'm told that usually there is fuel inside the vacuum line to the top of it when the diaphragm bites the dust. But I think the only way to be sure is to test it at the CSI fuel line.
The FPR does just that, ....regulates pressure so that you don't constantly RAM FUEL in that rail. So, when you replaced it, did it seem to not be AS RICH as before? If your performance improved, it could be that you've partially solved the problem...but if you still have a bent line or heading south pump....now, I would think you would be MORE lean, not less, seeing as the FPR reduces the pressure being forced into the injectors....RIGHT GUYS?
Another GREAT reason to get into that fuel line a lil more, 316, is that you can STILL have tons of crap in the lines. I replaced EVERYTHING in mine, including pump and filter, had RC Injector service to 'EXCELLENT' rating....but after THE FIRST TURN of the key, with a good pump, regulator and new CSI, something dislodged and went RIGHT INTO #2 INJECTOR, causing it to stick closed, instantly! LOL. I had to tear down the entire intake again, yank them all and they found a big blob of crap came out of that injector.
Might not have much relation to your issue, ...maybe it does...I'm just trying to share just how many STUPID LIL THINGS can go wrong and you NEVER KNOW until you start diggin in there.
RICH, EH? hmmmm. You're SURE your TPS is adjusted right?
The FPR does just that, ....regulates pressure so that you don't constantly RAM FUEL in that rail. So, when you replaced it, did it seem to not be AS RICH as before? If your performance improved, it could be that you've partially solved the problem...but if you still have a bent line or heading south pump....now, I would think you would be MORE lean, not less, seeing as the FPR reduces the pressure being forced into the injectors....RIGHT GUYS?
Another GREAT reason to get into that fuel line a lil more, 316, is that you can STILL have tons of crap in the lines. I replaced EVERYTHING in mine, including pump and filter, had RC Injector service to 'EXCELLENT' rating....but after THE FIRST TURN of the key, with a good pump, regulator and new CSI, something dislodged and went RIGHT INTO #2 INJECTOR, causing it to stick closed, instantly! LOL. I had to tear down the entire intake again, yank them all and they found a big blob of crap came out of that injector.
Might not have much relation to your issue, ...maybe it does...I'm just trying to share just how many STUPID LIL THINGS can go wrong and you NEVER KNOW until you start diggin in there.
RICH, EH? hmmmm. You're SURE your TPS is adjusted right?
Last edited by ChefYota4x4; 06-15-2010 at 09:36 PM.
#33
Registered User
So I replaced the following and I still havent fully resolved my problem. AFM, o2 Sensor, coolant temp sensor and fuel pressure regulator. I am no longer getting the "popping" sound from the exhaust or the bucking while driving, but she is still running rich and very rough. It feels like she has half the power of what she normally does. I went ahead and dropped her off at my local shop to get checked out. I told them all the symptoms and what I have replaced already, they said it might be the fuel pump. They are going to check it out in the morning and give me a call...
Chef......I don't know about the knock sensor. It could be a number of things. That's the fussy part about EFI's, eh.
#34
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iTrader: (5)
Yeah Thook,
I know Flecker had a HELL of a time with his Knock Sensor. He ended up modding the location, because he'd got it back together and .....BLAMMO, same code again with a brand new one. His was a 3.0 as well. Yeah, it should have a Knock sensor code, right? ....UNLESS his ECU is doing what mine was....NOT THROWING CODES!
Watching and waiting for update, 316....Hope it's a simple fix. Many on that engine aren't, but....one can never know.
I know Flecker had a HELL of a time with his Knock Sensor. He ended up modding the location, because he'd got it back together and .....BLAMMO, same code again with a brand new one. His was a 3.0 as well. Yeah, it should have a Knock sensor code, right? ....UNLESS his ECU is doing what mine was....NOT THROWING CODES!
Watching and waiting for update, 316....Hope it's a simple fix. Many on that engine aren't, but....one can never know.
#35
Registered User
If the knock sensor's working, it should throw a code IF there was engine knock. If it's not working.....not sending a signal, then it should still throw a code. In which case, I think there's something else wrong. Hopefully, the mechanics can figure it out for him.
#37
Well, I just got an update from the shop. Cylinder 3 and 6 are not firing! They are going to wait for the car to cool down (I live in Phoenix) and then do a compression check. They said it could be something as little as a few bad plug wires or bad injectors, but of course it could only get worse from there. Possible blown head gasket or blown engine - but I highly doubt. She only has 150k miles and has never shown any signs of engine trouble... Doesn't burn any oil or smoke or anything funky like that. Hopefully there is good compression in the cylinders, it will be a cheap fix and I'll be back on the road.
#38
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iTrader: (5)
Man, crazy, you wanted a 6banger and wound up with a 4! lol, just to lighten your mood, 316, trust me, I know how stressful it is looking at HUNDREDS OF DOLLARS! ....but you're right, it could be that simple. If it's injectors, and they quote you a VERY high price, ...you doing it yourself? When I first turned over my BRAND NEW BUILD, as I said, some crap came loose in the fuel line and forced #2 injector to stick shut. I never thought to ask you to check for that, .....what you do is just quickly tap the pipe for that cylinder, and before 20 seconds or so you can tell that one will be ICE COLD. Had to tear mine down again to get the injector out, not sure about the 3.0....but once you get into it, it shouldn't be that big of a job if that's the deal. Still, I didn't like how high your compression is, ..but then again, I don't have a 6, so maybe that's normal.
One question...."NOT FIRING"??? or "Not getting fuel"??? HUGE difference. If they said not firing, I would imagine that means you're not getting spark to #3 and #6, ....but they might find just what I said. Easy test with a noid light to check for power to those injectors, and easier test to listen to them and see if they're firing. Did you do that, 316, when I said, "stick a prybar to each one(or long screwdriver) and listen for them clicking away.
Personally, I think they'll find they are firing, and that you're rich because they're pumping fuel in there that's not getting burned properly. Timing way off, maybe? Malfunctional dizzy? Does the 3.0 fire 2 injectors at a time, Thook, unlike mine? Should be in the book, no? If it fires 2 at a time, and 3 and 6 fire at the same time....well, that could be telling, eh? Maybe a bad driver in the ECU or bad wiring to those two off the split in the harness?
Sorry, I'm just interested, not trying to insinuate that I know what's likely wrong here. Just trying to spark some true Guru's here. lol.
One question...."NOT FIRING"??? or "Not getting fuel"??? HUGE difference. If they said not firing, I would imagine that means you're not getting spark to #3 and #6, ....but they might find just what I said. Easy test with a noid light to check for power to those injectors, and easier test to listen to them and see if they're firing. Did you do that, 316, when I said, "stick a prybar to each one(or long screwdriver) and listen for them clicking away.
Personally, I think they'll find they are firing, and that you're rich because they're pumping fuel in there that's not getting burned properly. Timing way off, maybe? Malfunctional dizzy? Does the 3.0 fire 2 injectors at a time, Thook, unlike mine? Should be in the book, no? If it fires 2 at a time, and 3 and 6 fire at the same time....well, that could be telling, eh? Maybe a bad driver in the ECU or bad wiring to those two off the split in the harness?
Sorry, I'm just interested, not trying to insinuate that I know what's likely wrong here. Just trying to spark some true Guru's here. lol.
#39
Just heard from my shop. Compression check went awesome. It must be an injector issue. My mechanic recommended sending the injectors to a specialty shop to get tested. We shall find out the results tomorow sometime!
#40
Registered User
Man, crazy, you wanted a 6banger and wound up with a 4! lol, just to lighten your mood, 316, trust me, I know how stressful it is looking at HUNDREDS OF DOLLARS! ....but you're right, it could be that simple. If it's injectors, and they quote you a VERY high price, ...you doing it yourself? When I first turned over my BRAND NEW BUILD, as I said, some crap came loose in the fuel line and forced #2 injector to stick shut. I never thought to ask you to check for that, .....what you do is just quickly tap the pipe for that cylinder, and before 20 seconds or so you can tell that one will be ICE COLD. Had to tear mine down again to get the injector out, not sure about the 3.0....but once you get into it, it shouldn't be that big of a job if that's the deal. Still, I didn't like how high your compression is, ..but then again, I don't have a 6, so maybe that's normal.
One question...."NOT FIRING"??? or "Not getting fuel"??? HUGE difference. If they said not firing, I would imagine that means you're not getting spark to #3 and #6, ....but they might find just what I said. Easy test with a noid light to check for power to those injectors, and easier test to listen to them and see if they're firing. Did you do that, 316, when I said, "stick a prybar to each one(or long screwdriver) and listen for them clicking away.
Personally, I think they'll find they are firing, and that you're rich because they're pumping fuel in there that's not getting burned properly. Timing way off, maybe? Malfunctional dizzy? Does the 3.0 fire 2 injectors at a time, Thook, unlike mine? Should be in the book, no? If it fires 2 at a time, and 3 and 6 fire at the same time....well, that could be telling, eh? Maybe a bad driver in the ECU or bad wiring to those two off the split in the harness?
Sorry, I'm just interested, not trying to insinuate that I know what's likely wrong here. Just trying to spark some true Guru's here. lol.
One question...."NOT FIRING"??? or "Not getting fuel"??? HUGE difference. If they said not firing, I would imagine that means you're not getting spark to #3 and #6, ....but they might find just what I said. Easy test with a noid light to check for power to those injectors, and easier test to listen to them and see if they're firing. Did you do that, 316, when I said, "stick a prybar to each one(or long screwdriver) and listen for them clicking away.
Personally, I think they'll find they are firing, and that you're rich because they're pumping fuel in there that's not getting burned properly. Timing way off, maybe? Malfunctional dizzy? Does the 3.0 fire 2 injectors at a time, Thook, unlike mine? Should be in the book, no? If it fires 2 at a time, and 3 and 6 fire at the same time....well, that could be telling, eh? Maybe a bad driver in the ECU or bad wiring to those two off the split in the harness?
Sorry, I'm just interested, not trying to insinuate that I know what's likely wrong here. Just trying to spark some true Guru's here. lol.