Chevrolet S-10 Truck Starting Problems Answered

Chevy truck fuel Pump Assembly picture

1994 Chevrolet S-10 4.3 tbi. I never get the signal to turn on the fuel pump or fire the injectors but if i poor gas in the intake once the truck starts it runs fine. Any ideas ? I have replaced the fuel pump relay oil pressure switch and computer.

ProTech:
If you’re not getting a signal for fuel, then you either have a faulty crank sensor, or bad ignition module.

But the truck runs great until you cut it off. If you poor a little gas in the intake to get it started would that only effect the starting ?

Ok. If it will start by adding fuel to the throttle body and stay running afterward, then you have a bad fuel pump.

Don’t understand ???? Pump runs and can drive the truck at highway speeds. Pump nor injectors work while in crank mode.

User 551, let’s start from scratch. Are you checking for power at the fuel pump when you’re cranking the truck? And how do you know they don’t work? Do you have a noid light on the injectors?

Yes and have nothing.

Well getting to start by adding fuel to the throttle body is not going to turn on some special switch that will send a signal to the pump and injectors. I’m sure you probably just have a bad fuel pump that doesn’t have enough pressure or volume to start the truck, but at running speed can keep up.

Ok but I straight wired the pump and can ground the blue and green signal wire on the two injectors at will spray fuel then you can turn the switch over and the truck will run on its own . Trust me I know it makes no sense. Been turning wrenches a long time and I don’t understand it. Just can’t afford to throw money at it.

That’s a new one on me. There’s no way you have no signal, but then starting the truck by adding fuel will then turn on the injectors and pump. That’s just crazy. Good luck with that one.Chevy truck fuel Pump Assembly picture

Once the truck starts and is running you can remove the jumper to the fuel pump and it will continue to run.

The only thing i can think of is that you are not getting the priming signal to the fuel pump, that the ECM if faulty.


Chevy S-10 Won’t Restart

It turns over fine. Sometimes starter fluid seems to help, sometimes not?

Hard to say exactly why that is happening. It could be a fuel pump that is going bad, or an ignition problem, or even a computer issue. I would recommend a fuel pressure check just to make sure it is within specs.

I also asked you if the check engine light comes on at all?

Sorry I missed it? No the check engine light doesn’t come on.

OK it’s a good thing then that the check engine light doesn’t come on, as that would rule out a probable sensor issue. I would get the fuel pressure checked to start with, because that’s where the problem is most likely to originate from.

Thank you sir.


Throttle Body

Hey fellas I’ve got a 1998 Chevy s-10 that suddenly died on us, thinking it was the battery like AAA guy said we replaced it but the truck still wont start- might turn once then goes absolutely dead. have checked fuses, not getting any juice to the fuel pump- even tried to direct wire from battery to fuel pump and nothing. now if you pour gas into carburetor it’ll run fine till gas is gone ( i know not real smart ) but we’re not having any luck finding the ground wire either thinking maybe it was just losing ground..ive had four men look at this –any advice would be greatly appreciated.

Do you mean throttle body? Your truck would not have a carburetor on it.

Yes, throttle body.

OK that’s better. But I’m still a bit confused. You say it will go completely dead, but if you pour gas in the throttle body it will run? So it is going dead, like a dead battery, or do you mean it just won’t start, but it will crank?

Cranks fine like its not getting fuel

OK so then it’s NOT going complete dead. Have you done a fuel pressure check?

Yes but there’s no pressure. Fuel pump will not kick on.

So you could have a faulty fuel pump, a bad fuel pump relay, or even a bad computer.

Relay tested good.

OK then that leaves fuel pump or computer.