Starting the S10

[Nick1994]

In January I made a post about putting a fuel pump in a family member's 98' Chevy S10 2.2L that had been sitting for years. That link is here: https://bobistheoilguy.com/forums/threads/replaced-fuel-pump-starter-died.337096/

I hadn't had much luck with cranking since then, but this time after a lot of battery charging I finally got it to crank, it cranked good and fast but took a lot of cranking to get it to start. It wouldn't start unless I had my foot all the way to the floor on the gas pedal, and it won't idle. It also won't rev high at all, so while my foot was to the floor the RPMs were still reasonable. I only ran it maybe 30 seconds, it then started blowing out white smoke from the tailpipe. And some liquid came out of the tailpipe. Might have been gas, but didn't smell super strong like gas.

Also, now after looking at the video I see the oil pressure gauge is low and the security light is on. There was too much going on that I didn't notice at first. In January when I got the truck to run for a minute, I think the oil pressure gauge was ok and no security light was on at that time.

Could this be a bad sensor that's making it do this? Or fuel injectors stuck wide open? Or a sensor making them stick open?

 

[dishdude]

I'm going with two opposite ends of the spectrum here, an injector stuck open that's dumping fuel or a head gasket that's dumping coolant in a cylinder.

 

[JHZR2]

Could be any number of things. Do you hear the fuel pump prime when you turn the key to the on position? My 98 S-10 (v6) does that, and will fire first cylinder, first crank after sitting for 6 months (just did it).

The exhaust systems in these are large I guess, and tend to knock out a lot of moisture, which then weeps out a hole in the muffler. No idea if that’s the sort of thing that it might be though...

Cranking and running with throttle floored isn’t right though, as you can guess. Something else is wrong

What is the coolant situation?

 

[Nick1994]

Could be any number of things. Do you hear the fuel pump prime when you turn the key to the on position? My 98 S-10 (v6) does that, and will fire first cylinder, first crank after sitting for 6 months (just did it).

The exhaust systems in these are large I guess, and tend to knock out a lot of moisture, which then weeps out a hole in the muffler. No idea if that’s the sort of thing that it might be though...

Cranking and running with throttle floored isn’t right though, as you can guess. Something else is wrong

What is the coolant situation?

Fuel pump primes fine and it's full of coolant.

Another family member last ran it about 2 years ago, but I think that was just to move it.

 

[V70tdi]

How is the status on ignition ? Lifted the distributorcap and checked for corroded rotor and cap ?

 

[CharBaby]

How old is the gas?

 

[Lubener]

Maybe a ruptured diaphram in the fuel pressure regulator dumping gas into the intake via a vacuum hose? By stating you have to floor it to get it to start is allowing more air in to offset an extremely rich condition.

 

[92saturnsl2]

Any codes? If it's been sitting for awhile check for rodents, chewed wires, which could cause the random effects you describe. The fact that the security light and engine oil pressure (assuming it's just the gauge reading and not mechanical) is a new development (with nothing in between to cause it) makes me question this.

 

[eljefino]

Security failure would either let it run or not. The "passlock" (not passkey) would let it crank and catch and die within a second, this is not going on with you.

The low oil pressure indication is a bit of a concern-- I'd poke a mirror/ endoscope in the oil cap to see if you at least have oil on your top end. It could be something stuck in the sensor. If you could get it to idle okay you could then turn your attention to if it sounds "dry".

It sounds like it's running on two cylinders. That's the typical scenario-- a vehicle will run on half its cylinders at near WOT and idle albeit funky on 3/4. But then the question is, why? You have coil packs, so if it fouls one plug, it stops two. Pull the plugs after doing this and see what's up, if some stink of gas etc.

 

[JHZR2]

Maybe a ruptured diaphram in the fuel pressure regulator dumping gas into the intake via a vacuum hose? By stating you have to floor it to get it to start is allowing more air in to offset an extremely rich condition.

Yes but what else would come with that, especially if puking out a ton of water and/or fuel? Id think sooty black exhaust? The video sounds like a lawnmower.

OP how does the oil look? All intake boots and vac hoses?

I think the noise makes me wonder if it could be an air leak, and so the only way to get things burning is more fuel. I think I’d start by pulling all the spark plugs, keeping the pump off, and cranking the engine - see what comes out. It may be messy. Then investigate from there.

 

[OVERKILL]

Maybe a ruptured diaphram in the fuel pressure regulator dumping gas into the intake via a vacuum hose? By stating you have to floor it to get it to start is allowing more air in to offset an extremely rich condition.

Yes, but if that's the case, it should have rev'd to the moon or poured black smoke, and he's saying it didn't rev up. I'm wondering if it's only hitting on one or two holes, which would explain the low RPM and difficulty keeping it running without having his foot deep into it.

 

[OVERKILL]

Yes but what else would come with that, especially if puking out a ton of water and/or fuel? Id think sooty black exhaust? The video sounds like a lawnmower.

OP how does the oil look? All intake boots and vac hoses?

I think the noise makes me wonder if it could be an air leak, and so the only way to get things burning is more fuel. I think I’d start by pulling all the spark plugs, keeping the pump off, and cranking the engine - see what comes out. It may be messy. Then investigate from there.

Yes, a massive vacuum leak is a good thought.

 

[Warstud]

What brand of fuel pump did you use. And was the fuel filter replaced ?

 

[Nick1994]

How old is the gas?

When I replaced the fuel pump in January I siphoned out 6 gallons of old gas, there’s was very little left. I poured in 4 gallons of fresh gas

What brand of fuel pump did you use. And was the fuel filter replaced ?

Cheapo TYC fuel pump and new AC Delco fuel filter

 

[Warstud]

That cheapo fuel pump could be defective right out of the box. I would do a fuel pressure test.

 

[Nick1994]

Ok, I pulled off the plastic intake box thing and it was full of gas. It will idle now (no oil pressure according to gauge) but still not super smooth.

Oil kind of smells like gas too.

Pulled the spark plugs and #4 was dry, #3 was soaking wet, and #2 & #1 were kinda wet. Plugs in pic are left to right, 1-4

Any ideas?

 

[dishdude]

Those plugs look original. I think I would pull the fuel pump relay, get some new plugs, check for spark and reassemble.

Oil pressure sending unit is probably stuck from sitting.

 

[Lubener]

Yes but what else would come with that, especially if puking out a ton of water and/or fuel? Id think sooty black exhaust? The video sounds like a lawnmower.

OP how does the oil look? All intake boots and vac hoses?

I think the noise makes me wonder if it could be an air leak, and so the only way to get things burning is more fuel. I think I’d start by pulling all the spark plugs, keeping the pump off, and cranking the engine - see what comes out. It may be messy. Then investigate from there.

Look at his plugs, black, sooty and wet. Hardly from an air leak. Ruptured FPR can dump fuel in like that whenever the fuel system is pressurized.There's a vacuum line on his, it would take five seconds to check.

https://www.rockauto.com/en/moreinfo.php?pk=1298622&cc=1303849&jsn=469

 

[Nick1994]

What sucks is everything is hard to get to on this truck. You’d think being a 4 cylinder you’d have more room.

Any way to test the fuel pressure regulator?

I’m guessing this is it

 

[Warstud]

Disconnect the vac hose. If theres fuel in it....replace it.