2003 Tacoma won't stay cranked

I have a 2003 Tacoma Pre-Runner. I cranked it this morning and as soon as I put it in reverse to back out of the driveway, it cut off. The engine will now turn over just fine, but as soon as it turns over, it will immediately cut off again.

Does anyone have any suggestions as to what is causing this prior to me towing this puppy to a mechanic? Any help would be greatly appreciated.

You’re terminology is mixed up and that makes it hard to understand what is going on. Cranking is the act of the starter motor turning over the engine. Starting is when the engine begins to run on its own.

If I understand you correctly- this morning you cranked the engine and it started normally. When you put it into reverse, the engine stopped running. Now, the engine cranks and starts for a moment but then it stops running. Is that accurate?

First thing to check IMO is fuel rail pressure.

You are correct. It starts for a split second and then quietly stops (before I can even get my finger off of the ignition), as if I turned it off myself. No rattling or shuddering or anything like that.

I’m not familiar with “fuel rail pressure” or how to check it. Can you explain?

Sounds like you might have a bad ignition switch. When you turn the key one click to the run position, do all of the idiot lights on the dash come on?

As TwinTurbo mentioned, it could also be a fuel pump problem. Do you hear the pump run for a couple seconds when you turn the key to run?

There is a pressure test port on the fuel rail, usually located near the intake manifold. You can buy a simple gauge at most auto parts stores (~$15) that, similar to checking your tire pressure, you simply connect to the port and read the fuel pressure. If your fuel pump is failing this severely, a pressure reading will reveal it.

I’ll have to check later on the dash lights and pump noise since I’m at work and drove my wife’s car, but I didn’t notice anything out of the ordinary when turning the key this morning (other than the fact it doesn’t run for more than 0.5 seconds).

Any possibility that the engine isn’t getting enough air or that it “thinks” it isn’t getting enough air? This is all new territory for me.

People are funny, a couple of months ago I could hear my neighbor cranking away on his old Tempo. It would fire right up but die as soon as he released the key.

After about 15 minutes of this nonsense the battery was dead. I thought this is good & i’ll give him a hand with it when I’m not busy with other things.

The neighbors next slick move was to pull his other car out of the garage & jump the Tempo battery. Followed by MORE useless cranking.

So I went over and told him it isnt going to start until we figure out what the problem is.

Turned the key & no idiot lights. The “run” circuit in the ignition switch was open. Replaced the switch & problem solved.

Not saying this is your problem, but from what you describe, it sounds like yours is running until you release the key so it might be.

Not likely to be a lack of air problem.

Can you describe what this port looks like? I’m having trouble locating it. Thanks.

Okay, I decided to change the fuel filter since I’ve been wanting to do that anyway. I figured it couldn’t hurt and may be clogged or something. After 105k miles, it was dirty. I shook a lot of dirty crap out of it once removed. I guess that is to be expected.

I noticed while trying to crank it that there is a moderate electric buzzing/humming sound coming from the top of the engine, where I presume the fuel injectors are located. It occurs when the key is in the second position, just before the cranking position. Does this sound normal to any of you? If anyone has a 2003 Tacoma, if yours does this as well (or doesn’t do it) I’d be interested to know. It just seemed like an odd noise. Any thoughts?

I didn’t have the filter on tight the first time I cranked it and fuel gushed from the filter. Can I assume from this that the fuel pump is working? I also had my wife turn the key while I was under it and heard it hum, so I assume it is at least priming the fuel line. Any thoughts?

Thanks again

The mechanic states that my water pump has leaked coolant onto a wiring harness, which in turn shorted out my “brainbox”.

I did notice that I had refilled my coolant reservoir and that it was empty again 2 days later when I had the starting problem.

He seems like a good guy. Does his explanation sound remotely plausable?