2008 LC engine suddenly dies (1 Viewer)

[Mikec]

Hi All, Has anyone experienced the engine suddenly stopping as if it is out of gas? Has happened several time now. Usually starts right back up and drives and no codes.
Sometimes starts and dies, starts and dies.
It has also died just driving at regular speed going down the road.
It is at the Toyota dealer now being evaluated and they are baffled. Seems as if the fuel pump is bad, but he has sort of ruled that out. Again, no doses at all. Any input or experience would be appreciated
Mac

 

[Docboy]

Did you test the battery?

 

[bloc]

How has he ruled out bad fuel pump? That's what it sounds like to me. Possibly bad fuel pump ECU, especially if you have corrosion. @CharlieS dealt with that and @TeCKis300 put a fuel pump in recently, plus took pictures of the old one showing a potential design issue.

 

[TeCKis300]

@Mikec , what year and how many miles on your cruiser?

I tend to agree with @bloc and would highly suspect the fueling system. Key things to keep the engine running are air, fuel, and spark. Air and spark has several direct sensors associated where they would generally throw codes. Vacuum leaks would still be a good basic check but I assume Toyota ruled that out.

Fueling has indirect measures. Could be the fuel pump but I assume the dealer assessed fuel pressure and fuel trims to rule that out. Next would be the fuel pump ECU and your symptoms seem to correlate with what @CharlieS has document. Another would be the fuel level sender. These have been known to go out, showing misleading fuel levels when really it's near empty.


I wouldn't rule out electrical either to @Docboy s point. Check the battery terminal and grounds to be sure they are properly secured.

 

[Mikec]

Did you test the battery?

Thanks @Docboy. I believe so. But I’ll dbl check.

 

[Mikec]

How has he ruled out bad fuel pump? That's what it sounds like to me. Possibly bad fuel pump ECU, especially if you have corrosion. @CharlieS dealt with that and @TeCKis300 put a fuel pump in recently, plus took pictures of the old one showing a potential design issue.

Thank you @bloc I’ll ask again for hat he said about the fuel pump. He was showing good fuel pressure. I like the idea of checking the fuel pump ECU.

 

[bloc]

Thank you @bloc I’ll ask again for hat he said about the fuel pump. He was showing good fuel pressure. I like the idea of checking the fuel pump ECU.

Yeah if it is making good pressure when actually powered the pump may be ok. If you dig through Charlie’s thread his just kept shutting power off to it, if I remember correctly. The only diagnostic is to check for that, then try to replace the fuel pump ecu. Though a real Toyota tech may have more resources to troubleshoot it.

 

[Mikec]

@Mikec , what year and how many miles on your cruiser?

I tend to agree with @bloc and would highly suspect the fueling system. Key things to keep the engine running are air, fuel, and spark. Air and spark has several direct sensors associated where they would generally throw codes. Vacuum leaks would still be a good basic check but I assume Toyota ruled that out.

Fueling has indirect measures. Could be the fuel pump but I assume the dealer assessed fuel pressure and fuel trims to rule that out. Next would be the fuel pump ECU and your symptoms seem to correlate with what @CharlieS has document. Another would be the fuel level sender. These have been known to go out, showing misleading fuel levels when really it's near empty.


I wouldn't rule out electrical either to @Docboy s point. Check the battery terminal and grounds to be sure they are properly secured.

Thanks @TeCKis300 it is ‘08 w 260k on it. Yes, I think those were the things he did to rule out the pump, I’ll ask him to check ECU. Also, 1 thing he mentioned is that the VVT cams do rattle some at start up, and some potential of that interfering somehow. Lots to think about.

 

[CharlieS]

Troubleshooting the fuel pump ecu was a PITA. Replacement ended up being the only option. Was it Sherlock Holmes that said something like eliminate everything that is not the problem and the only thing that remains must be the answer.

Looked it up: “When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.” ~ Arthur Conan Doyle, The Case-Book of Sherlock Holmes