Sounds like fuel delivery issue. Either through contamination in the tank or the pump failing.
Holy DTC code hell!!! 2008 Limited
- Thread starter alia176
- Start date
chitown40
Member
You keep saying it has to be a fuel delivery issue, but fuel delivery is heavily reliant on electronics (ECU) and other electrical inputs to the system. It may be a combination of fuel and electric, but he's still getting misfire codes which wouldn't normally set if it was purely a fuel delivery issue. Also, our 4runners can still run ok with poor quality fuel. It's not great to run junk fuel the computer should adjust the mixture as needed if it's not burning perfectly.
Update Aug 1, 2015
I have been driving the vehicle around for the past 7 days (after the last 'meltdown'). For several days not issues no OBD codes. Then the last couple days I can, intermittently, feel the hesitation, sluggishness, surging but, absolutely no OBD codes are showing up. So I'm having issues and there are no codes showing.
The outside temperature has been a high of 95 and a low of 67. I've experienced the hesitation, chugging sensation in both temperatures. Again no OBD codes.
It doesn't seem to be length of drive time. I've experienced the issue right when I get in the car after it's been sitting and after it's been driven for 30 + minutes. It's more common after it's been driven for awhile to have its issue.
It does seem more inclined to 'act up' when it's under load. And it seems to 'act up' when I'm coming from a stop and accelerating.
I have been driving the vehicle around for the past 7 days (after the last 'meltdown'). For several days not issues no OBD codes. Then the last couple days I can, intermittently, feel the hesitation, sluggishness, surging but, absolutely no OBD codes are showing up. So I'm having issues and there are no codes showing.
The outside temperature has been a high of 95 and a low of 67. I've experienced the hesitation, chugging sensation in both temperatures. Again no OBD codes.
It doesn't seem to be length of drive time. I've experienced the issue right when I get in the car after it's been sitting and after it's been driven for 30 + minutes. It's more common after it's been driven for awhile to have its issue.
It does seem more inclined to 'act up' when it's under load. And it seems to 'act up' when I'm coming from a stop and accelerating.
toyo
Member
Does your scan tool allow you to run in a "Live Data" mode? Or record at all? You need to be able to observe the many different components when it either starts acting up or throws a code.
Have you or Toyota followed the proper diagnostic steps for these codes. I would start with the 301 thru 308 codes since the ECM is definitely detecting that these are misfiring.
Have you or Toyota followed the proper diagnostic steps for these codes. I would start with the 301 thru 308 codes since the ECM is definitely detecting that these are misfiring.
Her unit is a scanner only but I have a scan gauge that tells me all that info. I also have a software that can be used to record but realistically, she isn't going to be operating all this crap when shit hits the fan.
P0171, p0174, & p0308
Today I drove my vehicle about 8 times without any issues at all. When I was commuting home, the issues started again.
Again the same chugging, sluggish,and loss of power.... I immediately plugged in the OBD and pulled P0171 & P0174. I pulled those 2 codes Consistently until I started up a steeper hill at which point the CEL & VCS track flashed on the dash display and code P0308 came up along with P0171 & P0174. I cleared the codes and the lights turned off but the power, chugging, slug issue remained all the way home.
I kept clearing the codes as they came up and was able to chug home.
I was able to maintain speed at the posted speed limit, but when I would come to a stop it was very difficult to get up to speed again. The vehicle really struggled to accelerate. I was going between 55 MPH and 45 MPH.
Today the temp was about 95. When this issue started the temp was around 85. I have half a tank of gas.
Today I drove my vehicle about 8 times without any issues at all. When I was commuting home, the issues started again.
Again the same chugging, sluggish,and loss of power.... I immediately plugged in the OBD and pulled P0171 & P0174. I pulled those 2 codes Consistently until I started up a steeper hill at which point the CEL & VCS track flashed on the dash display and code P0308 came up along with P0171 & P0174. I cleared the codes and the lights turned off but the power, chugging, slug issue remained all the way home.
I kept clearing the codes as they came up and was able to chug home.
I was able to maintain speed at the posted speed limit, but when I would come to a stop it was very difficult to get up to speed again. The vehicle really struggled to accelerate. I was going between 55 MPH and 45 MPH.
Today the temp was about 95. When this issue started the temp was around 85. I have half a tank of gas.
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BlackWorksInc
New member
No,I don't think it's the relay at least. The issue sounds very much like a fuel delivery issue. The question is where is the fuel starvation coming from?
The issue is going to be determining if it's a physical issues (i.e. pump, pressure-related, injectors physically failing to open/electrically failing, ect.) or a driver issue (i.e. ECM shutting down momentarily, ECM not firing injectors correctly, incorrect fuel mapping, ect.)
The issue is going to be determining if it's a physical issues (i.e. pump, pressure-related, injectors physically failing to open/electrically failing, ect.) or a driver issue (i.e. ECM shutting down momentarily, ECM not firing injectors correctly, incorrect fuel mapping, ect.)
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chitown40
Member
Alia176 and I spoke for a while about this and we were thinking it had to be something faulty that would affect all the cylinders due to the codes he was getting. I'm thinking more like TPS and throttle body motor. BlackWorks, you ever see one of those two components go bad and NOT throw a TPS specific code?
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BlackWorksInc
New member
Lets not refer to me by my porn name on the forum. lol j/k
Honestly I am not thinking TPS or Throttle because the codes that are showing up are Lean rather than rich; which is implying that the AFR/O2 Sensors are not seeing enough fuel in the mixture. If there was an issue with the throttle body/blade control you should see a richer mixture due to a difficulty in getting air into the engine, but plenty of fuel.
The vehicle is acting as if it is starving for fuel, at least based on the DTCs and symptoms.
Though to answer your question, we've had pretty good luck with them setting DTCs for the TPS/Throttle Body; but I suppose it might be possible if it were borderline.
chitown40
Member
Sorry about that BlackWorks. Stupid phone autocorrect. I keep forgetting to read the posts before I press send. LOL
She noted that the vehicle is maintaining speed above 55 mph. It's after she slows down that she's unable to accelerate again and the vehicle struggles to get up to speed. That symptom right there leads me down two paths.
First, that after she decelerates the throttle plate starts to close, then the TPS malfunctions and the throttle body motor does not close enough to maintain a good idle mixture, ex. too lean and then the engine quits. Throttle is then stuck in a position too far open because the TPS is malfunctioning and she struggles to accelerate do to another lean condition. This is just a common sense theory as I know there are many inputs into the ECM that adjust all the above.... but I'm just trying to think a little out of the box.
Theory two: Fuel pressure regulator is failing in the "too high" position. The FJ62's had a problem where the fuel pressure regulators would fail "high" causing the inability to start the vehicle when it was hot. This could be a similar type fail when after the fuel system gets hot it basically vapor locks. That would explain why when she had the system tested at the dealer it maintained pressure... but the vehicle was probably cold at the time which didn't really uncover the issue.
Thoughts?
BlackWorksInc
New member
If the Throttle blade is physically sticking, then a DTC for the TPS angle correlation would be set almost instantly. Conversely if the TPS was malfunction a correlation DTC between what the accelerator pedal sensors/commanded angle and the Throttle Blade Commanded Angle/Actual Angle would be set. A borderline issue might cause some minor rough idle, poor acceleration, ect. but most likely not something this catastrophic without setting a DTC. (this would also be easy to see with freeze frame data of when the Lean DTCs are set.)
I'm thinking along the lines of fuel pressure/delivery as well. As I mentioned before, I have seen our injectors failing electrically when they get hot on some higher mileage Toyota engines; but I haven't seen the issue in a 2UZ-FE before. The problem is that we're still speculating it's a fuel delivery issue without having any hard evidence.
I'm thinking along the lines of fuel pressure/delivery as well. As I mentioned before, I have seen our injectors failing electrically when they get hot on some higher mileage Toyota engines; but I haven't seen the issue in a 2UZ-FE before. The problem is that we're still speculating it's a fuel delivery issue without having any hard evidence.
inscarguy
Member
could it be an electrical issue? maybe a rodent got in and chewed wires causing the periodic running issue? I have seen it before. maybe a feed wire or ground is bad, maybe two wires are hitting each other. those damn rodents can cause a lot of weird issues. I have seen it many times over the years.
I just got back in town from a fabulous trip to Ouray, CO. my 4R sat for the week. When I got back and started driving no huge issues so far (No complete meltdown). I can feel intermittent hesitation while driving at 70+ almost like a slight burp but I don't experience any loss of speed.
When I was passing a truck on a hill I noticed when the RPMs hit 4k I really felt the engin hesitating and struggling to maintain speed. Once I returned to 2k RPMs everything slowly returned to normal. Normal meaning, intermittent hesitation.
I also, when I was climbing a hill my engin was revving high but the RPMs didn't go above 2k. It sounded like the engin was revving at 4k. I made it up the hill and everything went back to normal. I was going about 35-40 MPH. It was morning commute. temp was around 70.
When I was passing a truck on a hill I noticed when the RPMs hit 4k I really felt the engin hesitating and struggling to maintain speed. Once I returned to 2k RPMs everything slowly returned to normal. Normal meaning, intermittent hesitation.
I also, when I was climbing a hill my engin was revving high but the RPMs didn't go above 2k. It sounded like the engin was revving at 4k. I made it up the hill and everything went back to normal. I was going about 35-40 MPH. It was morning commute. temp was around 70.
toyo
Member
Regarding the engine rev sound as you described that sounds like the fan clutch.
It does either sound like a really clogged fuel system, or an almost dead fuel pump.
It tends to get worse with load, and when you remove the load it gradually returns.
IMO, for diagnostics I'd either put a cheapish wideband sensor on it to monitor (you can sell it later for like 70% the price you paid pretty easily), or go ahead and replace the fuel pump and filter (isn't our fuel filter internal to the tank?).
It tends to get worse with load, and when you remove the load it gradually returns.
IMO, for diagnostics I'd either put a cheapish wideband sensor on it to monitor (you can sell it later for like 70% the price you paid pretty easily), or go ahead and replace the fuel pump and filter (isn't our fuel filter internal to the tank?).
Scott@Hightech
New member
After reading everything, I would question the MAF more than anything else. fuel pump could be the problem but they usually aren't intermittent with days between failures. MAFS on the can be tricky since they are electrical. i would def. find one to swap it for to rule it out. try unplugging the MAF when its acting up and see if the symptoms improve.
I had a 3rd gen a few weeks ago that barely ran and it was the MAF. it would sputter back fire and not rev up. almost didn't make it into the shop.
I had a 3rd gen a few weeks ago that barely ran and it was the MAF. it would sputter back fire and not rev up. almost didn't make it into the shop.
BlackWorksInc
New member
Eh, we've seen VVTi cam phasers, oil valves/actuators, ect. fail on various models (typically the FWD cars.) Can't say I recall much on the 1GR-FE in particular... I'm not entirely convinced it isn't a fuel issue (in some form or fashion be it the computer not commanding enough, or there physically not being enough.) A faulty MAF seems plausible, but should set a DTC if it is dropping out bad enough to cause these other DTCs and severe enough to stall out the engine.
