Help needed. 2015 4.0 6spd won’t start

Hello all,

New member here, trying to chase down an issue with my 2015 4.0 manual TRD sport 4x4. Truck is bone stock with 78k miles on it. 1 owner, serviced at Toyota with previous owner all its life, never gave one issue. Kinda my go to when I need a reliable means of transportation since my other commute is a modded mustang GT. Anyways, going down the freeway last week in 6 gear with cruise on at about 70 mph, it starts mildly skipping. I think ok maybe time for some plugs or coil. Then it starts absolutely bucking and I turn off radio, AC, everything but the engine. It keeps bucking and the engine just stalls. So I take it out of gear and coast to the side of the road. I sit there for maybe 10 minutes and try to start it maybe every minute or so trying not to be too hard on the starter. Won’t even try to fire. The starter cranks perfectly but it’s like it gets no fuel at all. New battery about 4 months ago and my code checker says good voltage. The biggest kicker to me is it didn’t throw any codes. Had to have it towed home and later that day after work I went out and made sure it didn’t blow any fuses, the box under the hood and under the steering column. All fuses are good.

Pretty sure it’s not bad gas because I’ve filled up at the same Racetrack-chain station that’s always busy for 2 years now. It’s not out of fuel because I put 20 gal in it the day before coming home from work. I’m pretty mechanically inclined from previous projects and cars I’ve had but this stumps me. Granted, this is my first Toyota and honestly have never had to work on it besides fluids, brakes, and tires. The only thing I’m thinking is fuel pump or crank sensor?? Maybe something emissions related? When I turn the key on I don’t hear the pump prime but maybe it primes on start of the engine? Idk. I do know I have tried to crank it several times since then and don’t smell any fuel at all. But I doubt it would flood anyway.

When I checked the fuses, I would periodically try to crank it and once it started, no skipping or anything. Ran completely perfect for about 1 minute and then completely died. No sputtering, just died. Today I used my second set of keys for it to see if it was a bad key and it initially did not start, maybe tried 5 different times. I just started playing around with the clutch start cancel button and it finally starts. Runs absolutely perfect, so I drive it around the driveway and get on the throttle pretty hard a couple times to see if I can get it to die. It does fairly well, and then I stop and let it idle and it just dies. Right now it will not crank back, tried the clutch cancel button again and still won’t start. Maybe that was a coincidence I don’t know.

Maybe something electrical? The truck is clean inside and out and no indication of rodents or anything getting to it. Usually it’s in the garage unless I get lazy and leave it out for me to drive the next day. I’ve never even so much as drove it on a dirt road. I don’t really want to take it to a dealer and pay for a tow and them to do everything I’ve already assessed, but I want to get it back going ASAP. So I’ll do that if I have to as a last resort.

I hate to throw parts at it but fuel pump and CPS is all I can think of. Unless it’s spark related instead of fuel? But I would expect a misfire code with spark issues. Tomorrow I’ll get a fuel pressure on it and see if it’s putting anything out. Haven’t had much time to look at it this week but what do you guys think should be my next course of action? Thx in advance.

 

You got it, fuel pressure test is next. They can be difficult to find adapters for, not many are off the shelf ready.

What I do in a pinch is remove the feed line and use a hose into a water bottle to see how fast it fills it. Doesn't really confirm PSI but shows volume and operation.

 

Good idea haven’t thought of the water bottle trick. I’ll report back tomorrow if I find an adapter

 

Fuel pressure adapter:

$31 BETOOLL Fuel Pressure Test Kit 0-100PSI with 9.497.896.30 Fuel Line Fittings

https://www.amazon.com/BETOOLL-Fuel-Pressure-0-100PSI-Fittings/dp/B07LF26ZTJ?

 

Welp I went out and disconnected the rubber fuel line off the hard line under the hood and got my brother to crank it and no fuel came out. It did leak some fuel out of the engine side when I pulled it off. So either the pump is completely dead or something is keeping it from putting out I guess

 

Can fuel pumps go out on these trucks at this low of mileage? 78k?

 

Ive never had a fuel pump go out this soon :’(

 

Turn the key on and jump across pins 3 and 5 of the C/OPN Relay with a paper clip and see if the pump runs.

 

Well, it's not unheard of. Do you drive it low on fuel often? It could just happen for no rhyme or reason tho. This sounds like it but there was a similar thread fairly recent that sure sounded like this and it was completely electric...a sensor if I recall.

 

Thanks! Will do, I’ll pick back up on it tomorrow.

 

Thanks guys for your help, much appreciated

 

Maybe give it a squirt of starter fluid (past the maf sensor) and see if it'll try and start, at least then you'll know you have spark

 

I actually never let it get below half. I’m too OCD, I top off every day I drive it lol. And I’ll look up that thread! I did read about a recall of tons of Toyota and Lexus vehicles about the fuel pump but I looked into it and 2015 tacos were not part of the recall. 2015 4Runners and FJs were tho (I think) which I thought was interesting

 

If it doesn't then we will need to do some power and ground checks.
I'm asuming your CEL comes on with the key on?

 

We see the odd 2nd gen tacoma fuel pump failure, not rare, no common.

Big thing is when its time to drop the tank, make sure to inspect the connectors carefully inside and out. Corrosion can cause the lack of fuel pressure as well.

I'm always happy when my red neck diagnoses works on here lol.

Also, try banging the tank like its a GM, sometimes that can get it to fire and 1000% ensure its a fuel pump.

@Dm93 I'm sick as a dog, I dont recall nor want to look up, the C/O is before the FP relay right? Can you just jump the large pins on the FP relay?

 

Yes it is, the circuit opening relay sends power to the fuel pump relay which in turn switches it between high speed (resistor bypassed) (relay off (pins 3 & 4 connected)) and low speed (through the fuel pump resistor) (relay on (pins 3 & 5 connected)).

It always starts on high speed (resistor bypassed) and switches to low speed a few seconds after startup.

 

My fuel pump went out on the highway, no warning just lost power and would not restart. it was around 130k.
Scary as frig, I was in the far left lane of a 4 lane highway in moderate traffic going 70 or so then lost power, hit the hazards and made it over 3 lanes trying not to get hit, and coasted to the next exit. super scary.

 

So just put a piece of copper wire between 3 and 5 and tried to start it with nothing. I did check to see if that relay is sending power and it’s got voltage through it. So I’m assuming this means the pump is getting power?

 

Also yes CEL comes on with key turned on. It never threw any codes or CEL though

 

Very similar to what happened to me. as long as it is just the fuel pump and once I replace it all is good I’ll be happy. Just hope it’s nothing more involved