Stadsport

Hi guys,
I just got a 93 Toyota pickup, extended cab and long bed, with the 3VZ-E (3.0L V6). It had been sitting for several months prior. It needed a battery and had a fuel leak. I fixed those, and went ahead and did a new cap and rotor, wires, NGK plugs, fuel, and air filter. It passed emissions, and I've been driving it around for about two weeks and it's been running great.

Yesterday, when I started it, it started fine, and then died immediately. I tried again, and it was fine. No hesitation or anything. It did the same thing later in the day, and a little bit later, my roommate went to use it, and he said he couldn't get it to start at all.
I went out to it today. It started, then immediately died. Tried it again, and it was fine. I restarted it half a dozen times, and it was fine every time. I ran ECU diagnostics, and it didn't return any codes (just blinked evenly/steadily).

My roommate is a Honda guy (EF civics specifically), and they have a common problem with the Main Relay that basically makes it do the same thing. I did some searching, but couldn't find anyone with the same problem. Because it's so intermittent, I haven't been able to determine whether it's a fuel or spark issue. My first instinct was something related to the fuel pump, but it doesn't seem to hesitate or bog down when it dies, it takes less than a second to go from running to dead.

Anyone have any ideas? I'm really unfamiliar with Toyotas in general (I'm a Nissan guy), but I know my general way around a car.

Thanks.

myyota

Did you replace the fuel filter when you did the tune up ?, if not i would start there first. Its also possible that the fuel pump is acting up, that sometimes happens when a vehicle sits for a long period of time.

Stadsport

I did replace the fuel filter. Where exactly is the fuel pump located?

Thanks.

myyota

Its in the gas tank, you either have to drop the tank or remove the bed to get to it.

Stadsport

I was afraid of that. Is there a more easily accessible connector that leads to the fuel pump outside the tank? I was wanting to stick a volt meter across the leads going to the fuel pump to make sure it's getting voltage (when the problem occurs), so I could rule it out as being an electrical problem elsewhere.

myyota

You might be able to reach the plug by the gas tank, but you will probably have to climb under the truck to reach it to check the voltage to the pump.

Stadsport

Ok, that will be my next thing to check when it starts doing it again. That said, do you know of anything else that could cause this? I've heard (from doing searching) that a bad MAF can cause the fuel pump not to activate. Would that throw a code, or would it only throw a code if there's an open circuit to the MAF?

myyota

A bad MAF can cause the fuel pump not to come on, but it might not throw a code. But i would lean more towards the fuel pump acting up. There have been many here that have bought trucks that have been sitting for a while and had the fuel pump go bad shortly after they got the truck running. It just seems that the fuel pumps don`t like sitting for long periods of time with out being used.

myyota

Another thing that i just thought of that can cause the fuel pump not to work is a bad core relay.

Stadsport

Fair enough. The only hole in this, to me, is how quickly it shuts off, but then I don't know things like, for example, if this truck runs the fuel pump for a moment after shut-down to keep the fuel system pressurized for the next startup (which my Z does). I guess I should try pulling a relay or fuse while it's running to see how it dies ("quick and painless" or "slow and horrible").

Edit: Core relay? Is this the one behind the glove box, or the one in the engine bay?

myyota

There is a valve built into the fuel pump that holds presure, but on an old pump this valve can go bad and no longer hold presure. if you pull the EFI fuse while it running the engine will die right now, not slowly. The core relay is behind the glove box, above the passenger side kick panel.