Engine shutting off during long trips. (1 Viewer)

[pcut]

Damn- It happened again! Both times it was after pulling a loaded trailer (rafting gear and gear for 3 people for a 6 day river trip) up Parley's Canyon ( 4200' to 7000'), 1/2 tank of gas, A/C on, no too hot (85 degrees). Ran great for 250 miles from Moab up and over the pass, down into Park City to the grocery store parking lot where one of the vehicles was parked where I stopped and turned off the engine. Tried to start and it "dieseled" and died. Waited 10 minutes and it started but only ran about a block until it "dieseled" and died again. Waited another 10 minutes and same thing. Waited 20 minutes and it finally started and got me the last mile home. Has anyone tried the cam position sensor replacement? I agree that it is a safety issue as the second time I blocked the right turn lane at an intersection. My Toyota certified indie says he has never heard of this happening, but I'm going to pass the cam position sensor information on to him and see what he says. At least it happened at the end of a 6 day river trip and not at the start!

 

[Utahfj62]

Has anyone tried the cam position sensor replacement?

Replacing mine on Wednesday of this week along with the 90k service. Then on Saturday we are driving from SLC to Southern California. Should be a good test.

 

[pcut]

OK- I bit the bullet yesterday and had my mechanic replace the cam position sensor. The new one definitely looked different than the old one so hopefully it will solve the problem. I guess that for a couple of hundred bucks it's worth it just for the peace of mind.

 

[kklaus121]

Resurrecting this thread. It is the time of year when it is starting to heat up again and would like to know if anyone has any updates/progress on this issue. I am getting to where I need to schedule my 90k service and am curious if the cam position sensor has "cured" the issue for anyone. It may be that it just isn't hot enough yet to know. Any how anybody have any updates? I haven't experienced the hot soak no start issue since late summer 2012, but it wasn't a very hot summer here last year.

 

[Utahfj62]

Resurrecting this thread. It is the time of year when it is starting to heat up again and would like to know if anyone has any updates/progress on this issue. I am getting to where I need to schedule my 90k service and am curious if the cam position sensor has "cured" the issue for anyone. It may be that it just isn't hot enough yet to know. Any how anybody have any updates? I haven't experienced the hot soak no start issue since late summer 2012, but it wasn't a very hot summer here last year.

I had my cam sensor replaced and have not had the issue repeat itself. I'm pulled a trailer on the same route it occurred prior when it was hot and zero issues. Cam sensor seemed to fix it for me.

 

[pcut]

Sorry to report that replacing the cam sensor didn't fix it. Drove back from Cruise Moab with new James Baroud RTT ( which is still for sale) and it died again at the first light off the freeway. Same deal as last time- hauling ass up Parley's Cyn, not too hot (80) ran great until I got off the freeway where it dieseled and died. Stopped for 30 minutes and it started up and has run great ever since. Now what ??

 

[ENGINE er]

fwiw, when my truck does this it always comes with a strong gas smell. Next time it does it, pip the gas cap while running and see if it is constantly pressured.

I suspect the issue is with the coal canister and since it only happens on hot days under heavy loads i can usually just pull over for 10 minutes and it will correct itself.

 

[mgilvan]

Sry to hear about this problem , I really think these truck are solid
Please excuse my lack of knowledge , Is the fuel pump in the tank or is it out side?
Because if I remember correctly the fuel pump in the tank gets cool down by the gasoline from the tank
And if the fuel pump outside of the tank gets hot ( and surprisingly it gets really hot ) it’ll stops working
So it might be the case of hot fuel pump ,
good luck guys

 

[TeCKis300]

Interesting thread. I personally have never experienced this problem and I've pulled some very heavy loads up some stiff climbs in hot whether without issue in my '06...knock on wood.

Postulating here, but what's significant that changed with '06/'07 is VVTi, and the revised engine management and fueling architecture that comes with it. The cam position sensor would relate to the VVTi function. Wrong cam angle could certainly produce this behavior, but it's an interesting TSB. Wonder if the original sensor has heat soak issues (odd thing).

I would primarily suspect the fueling system. Later generations of toyota's typically come with a non-recirculated fuel line system. Can anyone confirm this? These type are more susceptible to heat soak and vapor lock issues than traditional fuel line with returns. I would be suspicious of the fuel pump and or fuel pressure regulator. Lower head pressure can exacerbate vapor issues, especially at high altitudes. Anyone know where the fuel pressure regulator is located on the late 06/07 LX's? A non-return fuel system would typically locate the regulator in the fuel pump assembly in tank. I would personally attack those.

 

[kklaus121]

Interesting thread. I personally have never experienced this problem and I've pulled some very heavy loads up some stiff climbs in hot whether without issue in my '06...knock on wood.

Postulating here, but what's significant that changed with '06/'07 is VVTi, and the revised engine management and fueling architecture that comes with it. The cam position sensor would relate to the VVTi function. Wrong cam angle could certainly produce this behavior, but it's an interesting TSB. Wonder if the original sensor has heat soak issues (odd thing).

I would primarily suspect the fueling system. Later generations of toyota's typically come with a non-recirculated fuel line system. Can anyone confirm this? These type are more susceptible to heat soak and vapor lock issues than traditional fuel line with returns. I would be suspicious of the fuel pump and or fuel pressure regulator. Lower head pressure can exacerbate vapor issues, especially at high altitudes. Anyone know where the fuel pressure regulator is located on the late 06/07 LX's? A non-return fuel system would typically locate the regulator in the fuel pump assembly in tank. I would personally attack those.

I believe this is a return/circulating fuel system. The pressure regulator is on the fuel rail on the passenger side and the pressure dampener is on the drivers side. I may have these reversed as it has been two years since I investigated the issue as potentially having something to do with the regulator. I have installed a pressure gauge on the fuel rail, but since I have done that the issue has not repeated itself. Pressure is always 42-44lbs.

pcut: I read Utahfj62's reply as the cam position sensor replacement HAS fixed the issue.

 

[F16Chuck]

Glad/Sad to see this thread up again. I have a 2007 with about 86,000 miles on it. I wrote last year with this same problem (also in SLC Utah) but the weather cooled off and no further problems, so clearly heat related. However, it seems to me unlikely to be entirely due to heat, since it seems to me there is not enough time to cool off to have it restart in just 10 minutes.

Anyway, just started happening again. A couple of thoughts: Each time it was close to or over 100 degrees. Each time the truck had been run for an hour or two. Each time the tank was about 1/8th full. Each time I suspect the fuel had ethanol in it. I get my gas typically at Smiths (premium). I have not had the cam position sensor changed, but getting close to my 90,000 service so will have it done there. It seems like it is also mileage related, so may be some kind of wear item.

So this time I filled the truck at Craig's service station on 1300 East, which sells ethanol-free premium fuel. I also put in some fuel treatment (left over from my Ducati) to theoretically deal in some way with the ethanol in the fuel. I will write back in with the results.

It seems so classically like vapor lock, even though the Lexus service folks said that was impossible with a fuel injected engine which makes sense to me. It also seems like the cars back in the 70's, when emission controls were first put on. You would shut the car off in those days, and it would continue to run for 15-20 seconds. So maybe it is something with the vapor canister return system. The truck is so reliable otherwise, and a keeper, that I would like us all to put our heads together and come up with a solution. Lexus has to know about this, but the service department has not been helpful.

 

[kklaus121]

I had this issue regularly two summers ago when it was really hot. Since then we have not see that high of heat consistently here in Colorado Springs. I had my 90k service done two weeks ago and had the cam position sensor replaced. Earlier in the week I made several runs to Florence and back to Colorado Springs for work and the temperature in Florence was 102 that day and I did not have any issues. This is not enough testing to claim the issue solved. I also have not had the strong fuel vapor odor in the garage after driving in the heat. I need a couple of hot days here so I can do some further testing and report back.

 

[pcut]

So what I have been doing when I am coming back up Parley's Canyon on a hot day is to keep the revs up to about 2500- 3000 with the trans in neutral if I am at a light or slowing down significantly. When I start out again, I let the revs drop to about 1500 just long enough to get it into Drive and then hit the gas to get going. Seems to work since I haven't had it die on me again. Would really like to find a true fix though so if anyone has the answer, I'd love to hear it. Never smelled gas, but the fuel level was definitely low given that every time it has happened, I was coming back from Moab where I had filled up - +- 250 miles depending on whether or not I go through Price or Duchesne. Tried taking off the gas cap last time and that didn't do anything.

 

[tmils470]

Has anyone checked the Tundra forums for those symtoms? I assume they have the same motor for the same years. That would lead to the cam sensor. If they don't have same problems it could lead to different fuel routing/evaporative systems or fuel pumps.
Just a thought.

(I had the exact same symtoms going to Tahoe on a 110 degree day in a Volvo Wagon, it was the fuel pump)

 

[pcut]

I spent about an hour searching through various Tundra forums and the only threads I could find seemed to relate to running out of gas. What would I look at on the fuel/evap/fuelpump systems?

 

[tmils470]

I spent about an hour searching through various Tundra forums and the only threads I could find seemed to relate to running out of gas. What would I look at on the fuel/evap/fuelpump systems?

If you can not find same problems and the engines are the same, then that points to something other than the actual engine. Could be fuel system routimg, fuel pump/filter. It should show up on Tundras and Sequoias since there a lot more of them on the road.
I notice from the original post that the problem went away whe he poured gas into the gas tank, could this have cooled the fuel pump? Or would it have started just by resting the same amount of time?
Does anyone have this problem with a full tank? On most cars the fuel in the tank also helps to cool the fuel pump.
Is there a relay for the fuel pump that can overheat?

 

[SWUtah]

Since it's not a 2005 or older 100 series problem, what are all the engine/fuel system parts difference between them? Now you know what components to look at. I bet it's emission difference, and the problem is in that system. Might be a design problem that can't be fixed. Do the Aussie 2006-7's have the same emissions system/requirements? If not are they having this problem? We have a lot of Aussie members. Maybe they can give their 2 cents?

 

[1meancruiser]

I had the same problem again yesterday. Happened a total of four times to five times. I drove from 1000 feet elevation up to 6000 feet elevation, near sequoia nat park, in 68° weather and fuel was no less than three quarters full. Relatively light 400 lbs load, but lots of climbing.

Engine would start idling very rough and then stuttering after Hillclimb's, and than it would stall. After a 2 to 5 minute wait, it would restart like there was nothing wrong. Ever time it was after a hill climb.

I replaced the crank sensor, and I think the canister as well, I have to check with my mechanic. I think the next thing to look into is the fuel pump. I AM VERY FRUSTRATED WITH THIS ISSUE!

 

[1meancruiser]

Does anyone know where to check the fuel pump part number? Can it be seen from underneath the car or do you have to pull the tank and look on top of the tank to get the part number?

 

[SWUtah]

Is it the air pump on the 2006-7's?