2008 v6 going into limp mode on acceleration

Yesterday i posted about my vehicle having a rough idle when in gear, this issue has now developed into the vehicle going into limp mode when i hit the accelerator too hard (getting onto highway). The check engine light comes on and it will not accelerate properly. this issue has come about with the extremely cold weather in my area. Assuming it is correlated but not the root cause
Ive got 134k miles on this vehicle and its been relatively well maintained, and never driven hard. where should i start with diagnosis for this?

 

It would be nice to know what codes it's throwing.

 

Take your vehicle to Oreilys or similar. They can pull the CEL codes and then you will know whats going on. Best part, they do it for free.

 

The O'Riley's here will not tell you the codes, they just try to sell you the part to supposedly fix it. AutoZone is great though. But like any other chain store the exact opposite could be true somewhere else.

 

What? Shame on them. I can honestly tell you that doesnt happen at Oreillys by me. They now have a new scanner that will print out the cause and possible fixes. Now i know that none of them will do a reset for liability reasons but Ive never experienced it where they wouldnt give me the codes.

 

While you're at the auto store get a bottle of this and follow the instructions on the can to clean your MAF sensor.
https://www.autozone.com/p/crc-mass-air-flow-sensor-cleaner-05110/36011

 

That's nice!

 

Hope you learned your lesson. An Italian tune-up a day, keeps the carbon deposits away

But yeah read the codes with a scan tool. Could be one of 30 possible culprits otherwise.

 

The issue is a cylinder 1 misfire. the throttle body is also disgusting so ill be cleaning that

 

Properly clean that and the MAF. If you have idle issues afterwards just put some miles on it.

 

A compression test is good idea for cylinder No. 1 before changing parts to verify it's good (valves/valve seats as well). I like to hold off on touching anything else so I don't inadvertently introduce a new problem to existing one.

 

Limp mode, and rough idle sounds like the throttle body to me.

 

I swapped coild and plugs around randomly and then it gave me 4 misfire codes for 4 cylinders.
I just bought a new MAF sensor. Didn’t mess with cleaning it.
new MAF+cleaned Throttle body, and replaced a 4 year old battery and im running no check engine light. got on the gas super hard this AM and no issues. Also it idles a lot stronger in park that i noticed

 

OEM MAF sensor? If not I sure hope you didn't throw the old one away. Most aftermarkets don't last long.

 

I kept the OEM one but what can else can I even do? It clearly was the issue, and honestly it wasn’t that dirty, i will eventually get some cleaner and fully clean it, i guess i will keep a spare in my glove box too in case im on a road trip and it gives me issues again

 

What brand replacement did you get?

Not sure if they make MAFs but i would probably be comfortable with a Denso or Bosch, or even a remanufactured Cardone unit.

 

About codes, it’s a smart investment to buy a Bluetooth OBD reader and app. I have

Veepeak OBDCheck BLE Bluetooth OBD II Scanner for iOS & Android, Car Wireless Check Engine Light Code Reader Diagnostic Tool

this one ($32 on Amazon) and use it with the OBD Fusion app. This enables you to get the codes on the spot, reset them when appropriate, and monitor all kinds of data. There’s an optional Toyota add-on that is worth buying IMO.

I have many examples of this combo paying for itself. I was towing a 4K lb. travel trailer on vacation 1000 miles from home when I suddenly got the ABS, VSC, and TRAC lights. Pulled the codes, did a little reading online, and was very relieved to learn that my problem was headlight bulbs, not brakes. It was the odd deal where LED bulb fans can throw electromagnetic interference that the ABS system reads as a fault. I was able to confirm this by resetting the codes and observing whether or not the fault only occurred when the lights were on, which it did. Bought some inexpensive replacements at Walmart to last the rest of the trip and swapped out for better LEDs when I got home. Highly recommend having a reader and app.

This is my dashboard set up for routine monitoring. BTW, this was near the end of a full day of offroading. The external transmission cooler was apparently doing a great job.

 

Well, I am back to square 1, or at least close to it.

I have replaced the battery (it needed to be done regardless)

I have replaced the MAF, I have cleaned out the throttle body. upon startup, the engine sounds like its running stronger. so i think the issue still could still be somewhere in those two items.

I seemed to have stopped the engine from being in limp mode. but this morning i did a loop around the freeway around town, about 10 miles. i got on the gas hard, it was running well, and would accelerate, and i was hitting the gas hard getting to see how it responded. and for a while it was fine.

towards the end of the drive, i felt a couple noises that could i could have been convinced were small misfires. and then it went back into limp mode.

the vehicle is throwing multiple misfire codes. i have checked the codes multiple times and it shows different cylinders, misfiring.

what is next step here? remember I have replaced the spark plugs and ignition coils within the last 3 months, but there were no issues after doing so, until now.

the engine seemed to be running strong as ever this morning, prior to going back into limp mode. so i believe it could be something with the ECU just triggering this, but I have pulled the ground wire off the battery for 15 mins at a time more than once, hoping to reset it. i am hoping it is not fuel injectors but if that were the case, wouldn't the issue be localized to one cylinder? its not realistic to think all 6 went out at once

 

I feel for you. This kind of stuff is really frustrating. That said, just because things were replaced doesn’t mean they’re working correctly. I replaced my coils and had the first misfire in the 11 years I’ve owned the truck soon thereafter. I stupidly bought aftermarket coils and one of them was faulty. To their credit, the company immediately sent me a replacement and the other 5 have been fine. Fortunately, I had kept my OEM coils so I was able to swap one in. I just left it and I’m keeping the warranty replacement among my spares.

I learned from that to keep a spare coil in the truck. With the ability to read codes, and the fact that the coil is the culprit very very often when misfires happen, having that spare could turn the problem into 10 minutes on the side of the road, then on my way, instead of a flatbed ride home or to a shop.

 

I've experienced something similar-ish to what you are describing in my Tundra. I was getting misfire codes and when I tried everything before I realized that it was acting like I didn't have enough fuel. It would sort of bog when accelerating too hard or going up a hill. I replaced the fuel pump and the problem hasn't returned. Hopefully that helps.

 

What brand of coils? What plugs did you used? If it's not too much of a pain pull them all out and make sure everything still looks good and they all look the same.

 

they are a TQR Brand, yes i know not a full OEM quality, but i was able to read enough online and find enough reviews that i have confidence in them. i unplugged and shuffled all the plugs and coils around on the passenger side, orignially i had just a code for cyl 1 so i swapped everything out on the side with Cyl 1 to see if the issue would move to a different Cyl on the same side when i re ran the codes. i re ran the codes and it was showing misfires on 4 different cylinders, (passenger and driver side), so while i may be criticized for using less than OEM parts, they do not seem to be the issue

https://www.1aauto.com/toyota-4runn...sZMQBL8QqO2KhcxebYzRVgRPHcsqZId4aArAoEALw_wcB

 

You used the TRQ spark plugs?

 

Might want to check out the fuel system a little bit harder. Sounds like it's having fuel pressure issues. Failing pump or clogged filter.

 

Coils are seated properly and connections to each one are strong and snapped in? The fact that you originally had a Cylinder 1 misfire only, then you did some swapping around and now you have 4 different Cylinder misfires is weird. Although that wouldn't really explain the new drivers side misfire...

 

If you look around you can find this little red ODB2 code scanner costing around $20 i found mine a while back at a Walmart, it's just a simple code finder and then you can google the found codes and know what they are also you can then clear them. I then later bought a INNOVA 5610 and it can do a lot more and give you a lot of live mode information, not implying everyone should buy one just saying it will give you some real information.

The Auto Parts stores are nice but you need to understand they want to sell you parts, you might need them or maybe they won't be the correct part, your auto or trucks computer will wait for three live drives many times to give a check engine light, you clear it and many time after driving again the check engine light is nolonger on, so having your own OBD2 scanner gives you a lot of real information and control.

 

This sounds like either his coils/plugs are junk and giving him issues or as mentioned a couple times already it could be fuel issues. @cp5555 you replaced the coils as preventative maintenance? How long until the misfires started? You then moved them around and went from cylinder 1 misfire to 4 different cylinders misfireing at the same time? Do you still have the old coils?

 

I bought the vehicle at 123k miles and they had never been done. I charged them at 130k miles and had no issues for the first 4k miles. 4k miles and 90 days before the issues started. when i pulled the old plugs they were toast so it definitely needed them

 

Do you still have the OEM coils or did you throw them away?

 

Right now with what I know I'd say you need new coils. I know they were just replaced but electronics don't like cold so that's probably your problem. I'd go with denso or Toyota or if cost was a factor ngk. I'd replace the plugs with denso or ngk too. It's not my vehicle so do what you want but this isn't a area to skimp.