Ecu misfire?
- Thread starter TTO5
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- Thread starter
- #23
I plan on putting it on the lift at work tomorrow and getting my fine tooth comb out
bloc
SILVER Star
AFAIK yes a new ECU from Toyota would need programming. At the very least your VIN has to be coded in, and I’m sure there is other stuff to do as well.
- Thread starter
- #25
Ok
shouldn’t the shop that did the install be doing all this. You had to spend heaps of money with them, they should be making this right.
Did you reuse your old ecu? You had to of, right.
It didn’t have an issue before, I doubt it has one now unless the harness is not plugged in all the way.
This is just a blind guessing through the net.
I would take a day off and drive around near the shop until the problem occurred and then go back to the shop.
I don’t think I’d have anyone else look at it yet, the shop that did the engine install might then refuse to warranty their work. Idk.
I would be wiggling all elec connections/checking grounds. Look everywhere for a pinched wire or anything. The same as what others have said
Solder joint could be losing connection with warm inside a sensor.
I recently chased a no start issue for a month until I found remnants of an aftermarket car alarm was pulling on the wires as the steering wheel moved into position when I put key in ignition. One of the hardest to find issues I’ve ever had with a vehicle.
Did you reuse your old ecu? You had to of, right.
It didn’t have an issue before, I doubt it has one now unless the harness is not plugged in all the way.
This is just a blind guessing through the net.
I would take a day off and drive around near the shop until the problem occurred and then go back to the shop.
I don’t think I’d have anyone else look at it yet, the shop that did the engine install might then refuse to warranty their work. Idk.
I would be wiggling all elec connections/checking grounds. Look everywhere for a pinched wire or anything. The same as what others have said
Solder joint could be losing connection with warm inside a sensor.
I recently chased a no start issue for a month until I found remnants of an aftermarket car alarm was pulling on the wires as the steering wheel moved into position when I put key in ignition. One of the hardest to find issues I’ve ever had with a vehicle.
- Thread starter
- #27
Thanks all good points there. I work at a yota dealer so it's just easier for me to use them. The shop that did the install is basically saying it's nothing they did and coincidence. As I'm the one thar supplied the replacement engine there is only so much I can expect from them . That being said I did some testing at work today with one of my technicians. So once it warms up to 170 plus it goes into the flashing light with the codes. If I clear it comes back right away. Shut truck off let cool for a bit start back up light on solid for a few moments then starts flashing. I checked several things today and each time the behavior was the same. I wiggled the ecu connections while it was running and had no change. I unplugged the 2 ecu harness connectors let truck sit like that for 15 min. Plugged back in and started truck. Engine light not on and no codes. I let it run up to 185 degrees all ok. I've so far driven it 15 miles and ok. So my question is the only thing that made a change was the unplugging and reconnecting the ecu. If the problem was elsewhere should it be showing up right away? Does the ecu keep the mil Data stored after unplugging? I will drive it the next couple days and see what happens. The shop that did the repair said that was their experience also after disconnect/reconnecting ecu. Could be a bad ecu after all? The engine is from a 2011 lx570 and I confirmed is the same part number as my 2010. Ideas,
gaijin
GOLD Star
On the face of it, sounds to me like there is a bad/intermittent connection(s) in the ECU connector(s). Maybe just a bad mating of the ECU connector and the ECU? I'd spray all connections on the ECU and on both connectors with some non-residue contact cleaner and run it to see if the problem ever comes back.
Just my US$0.02.
HTH
- Thread starter
- #29
Still hasn't tripped back on. Drove several times today. As they say time will tell.
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- #32
The saga continues. I made a video this morning sorry it's 5 minutes long but wanted to record several things. And I wasn't able to get the mil to go away by unplugging and reconnecting ecu plugs like I did the other day. When you restart the truck the light is solid for about 15 to 20 seconds then you feel the roughness and light begins to flash. Here's the video
I'd still check compression before you start swapping out stuff. Compression might tell us something. I'd also check the fuel injectors for those two cylinders.
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- Thread starter
- #35
Existing ecu. It's not at the shop that did the swap. I have it here at my toyota dealer and currently waiting for them to check it out
Happen to know if it came out of a 200LC, LX570, or a Tundra?
I know same motor but I’m 100% convinced my Tundra 5.7 had a completely different Tune stock
- Thread starter
- #37
It's from a 2011 lx570. I matched the serial number on the engine to the actual truck it came from. Only 45k miles.
- Thread starter
- #39
I hooked up a scanner I got from Amazon and got the following info. The 783 misfire count showed up once the truck went into limp mode and engine light started flashing. Can anyone comment on the significance of the 783 number being the same on cylinder 4 AND 7? The other pictures show the data while engine is running but before the light starts flashing.
