Tacoma Died Randomly While Driving! :(

EDIT: My fuel level sending unit (or my gauge! or both!) was off, so we just ran out of gas!

Continue reading through, though for a really awesome discussion on what could possibly go wrong in this situation, and how to test for those things.

Thanks to everyone for the help!


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Original posting:

Hey!

I did some searching through the forums, and on Google, and haven't found anything similar to this (which, I guess is a kind of blessing, right? Because maybe it isn't a common issue and failure and we wont have to worry about it again after we fix it?) so I figured that I would pick your brains about this weird incidence.

So! About a month and a half ago, we bought this lovely 2009 PreRunner Tacoma. 104k, we have put about 3k miles on her since we bought her. (We made some pretty big trips out to the desert with her, thank goodness she did well for us then!) Last night, we were coming home from the grocery store at 10:30pm, and out of NOWHERE, the engine just dies. We were on the highway, doing about 70mph, and we had to coast into the left hand break down lane.

We pulled over, put the transmission into park (yes, she's auto) and tried to restart. Crank, crank, crank, NOTHING. We tried a few more times and every now and then we heard the deceiving slight hiccup of wanting to come to life, but no dice.

Our tools were limited, but I managed to find a plastic fork, with which I was able to remove and swap the EFI relay with the horn relay and at least rule that out.

I went through the basics in my mind, "What makes an engine run... Fuel, Air, Spark, Timing!" With only the plastic fork, I was unable to remove a fuel line and check for the actual function of the fuel pump, but as my husband turned the key, I kicked the fuel tank directly below the pump... no change. I could hear the buzzing of the fuel pump in my ear when I put my head on the tank. In my experience, either a fuel pump works or it don't..... I've never heard it make noise without pumping before. Also, we have between E and 1/4 tank of fuel. My husband is pretty sure that he has let it get lower than this before, and had the fuel light come on. (I know this is bad for the fuel pump to run with so little fuel - the fuel cools and lubricates the pump!! So I have never seen it this low before. Is this too low? IS this "running out of gas?" :/



In my experience with fuel pumps, they quite often die after full-up, if they are going to. Something about the scenario of being low on fuel, running hot, then immediately being submersed in fresh, cold fuel, seems to shock them into death. That was so not our case.

I pulled off the air filter and smelled the engine, but didn't smell fuel. I still haven't ruled this out, but I do not know how to disconnect those funky lines. I will look this up later, because I really want to verify one situation for reals before moving onto the next.



When the tow truck brought us home, I continued to brainstorm. "Fuel, air, spark.... timing!" Of course, I do not have a timing belt, I had a timing chain, so if that were to have stretched (heaven forbid!) I would maybe see a cam sensor code, or if my crank sensor dies, that would cause the truck to stop running for sure! I grabbed my scan tool. No codes were stored, and I had an accurate RPM signal.

WELL, ........ SHIT! There go my only 2 theories. I thought for sure, after a while of driving, and suddenly out of nowhere, either dead fuel pump or crank sensor would be the culprit.

Now, its morning and I went out to start the truck. Still no dice.

I decided to check for spark. Using my spark checker, I removed a coil pack and placed the checker between the coil and the spark plug. I had my husband try to start the truck while I watched for spark. To my disappointment, we have spark.

We tried starting the truck with both keys, in case one of them had a chip gone bad or something, but both keys produce the same result. I am a little at a loss at this point. Does anyone have any ideas? I think that my next step is to be sure sure of the fuel. I will figure out where I can disconnect the line, and maybe purchase a tool if needed to disconnect the lines. I have a full set of GM/Ford ones.... why not Toyota?!! :/

As I troubleshoot, I will update this thread. Not just for the added bonus of having input from actually smart Tacoma owners out there, but also to help anyone else who may, in the future, have this weird freak thing happen to their beloved trucks!

Thanks, everyone!

 

Not trying to sound like a smart ass here, but do you have fuel? It's possible your gas gauge is inaccurate and you ran out without realizing.

 

you don't need to disconnect the fuel line there should be a valve that looks like a valve stem on a tire but on the fuel rail

 

Thank you!! No, you are absolutely right. I do not know. This is technically my husband's truck, though I drive it occasionally on super hot days (my beloved daily driver doesn't have A/C). BEfore you even replied, I had updated the thread with a photo and a question: is this too low? He says he has run it lower before, and that he believes he has run it low enough on fuel to make the fuel light come on. I have never witnessed this, as I never let it get this low when I drive it, I know its not good for the fuel pump. As far as I know, we could have a fuel level sending unit failure! I am not 100% on this.

Thank you so much for the feedback. I will verify this for sure.

 

Oh, a shrader (spelling?) valve! How ingenius! I will check that right now, thank you SO MUCH for the helpful reply!

 

Your fuel pressure should be between 50 and 70 psi anything below that I would say bad fuel pump.

 

Any corrosion around the battery cables? Are they tight? What about the battery voltage? I'd also check the grounds where they connect to the body.

My Tundra was doing this thing occasionally where it would start them immediately die, like it had no fuel. I could go out 30 minutes later and it would start like nothing was ever wrong. I cleaned the battery cables and so far it hasn't done it since.

 

Any check engine light? My old Tacoma had the same symptoms when my MAF sensor went bad. Only it died at a stop sign and wouldnt start back up until later...but it did throw a check engine light.

 

Going off your pic, and experience driving my 08, I would expect about 20 miles of driving before low fuel light came on. I have routinely taken my vehicles down to E and never experienced fuel pump issues in 40 years of driving. But, maybe I've just been lucky (knock on wood).

 

Crankshaft position sensor?

 

So helpful! I did notice some corrosion on the negative cables, new factory battery, and voltage is good. I will clean the cables and report back! All ground straps in proper location, and positive cable is in good shape.

No check engine light, no stored codes. My scan tool shows activity from the AFM, and although I'm not positive what the values should be, I am happy that there is something!


Also, I am seeing no schrader valve on the fuel rail. I removed my intake and saw, to my disappointment, that someone (whomever had previously worked on the truck.... I have extensive dealership records, so probably them!) had broken off the nipple on the rear of the passenger's side portion of the 2-piece intake. This is where the fuel pressure regulator must get its vacuum signal. They had tried to "fix it" by installing a red straw (like form a brake cleaner can) into the broken nipple, and into the other side of the regulator. It was totally clogged. I got a new brake cleaner straw, and re-installed, but alas. That did nothing.

Cranking over, I still don't smell fuel so I really believe that this is where we are headed.

 

Entertained?! :'D Or..... do you know something that I don't!?

 

But wouldn't that throw up a code?

 

That is what I thought, too! But alas, I have RPM signal when cranking.

Thanks for the input!

 

Actually, no! It wouldn't necessarily. Cam will, but from my experience, not crank. Some vehicles take 30 seconds of cranking to throw a code, if they do at all. I am new to Tacomas, so not sure how she would let me know her sensor is bad. I just check for RPM signal, and if I have it, I move on to fuel pump

 

What tool are you using to check for RPM?

 

Is the mass clean. I've seen a blade of grass in the mass cripple a truck before

 

Just watching intently to see what the problem is, I do not have anything useful to add that hasn't already been said.

 

I'm sorry I was wrong. The fuel pressure on the 4.0l should be between 40 and 42psi