'00 Silverado won't start

My neighbor brought her truck home last night on a flatbed. I put my scan tool on it, no codes. It started a few times but died soon afterward. The Low Fuel light was on, so she put some gas in. Now it won't start at all. It cranks strong, so there's no problem with the battery.

Seems there should be a trouble code for low fuel pressure, but I can't find one.

I'm not a Chevy guy, but OBD II is not a Chevy thing. My Bronco told me via the OBD I codes that the fuel pump was bad, I'd expect OBD II to tell me the same thing.

I assume the fuel pump lives in the gas tank, but don't know for certain.

Can one of you guys tell me if the fuel pump will cause the truck to refuse to run but not throw a code at the same time? And, confirm the location of the pump?

Thanks,

Reply to
Jeff Strickland
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Probably in the top of the fuel tank. Give a shot of ether in the air intake, see if it runs for a second. Fuel pump is a VERY common thing to go wrong on Chevrolet. On my 1989 Blazer, I sawed through the floor and replaced it that way. It was in the center of the tank, not to one side or other.

I don't know about the codes.

Reply to
Stormin Mormon

Pump failure will NOT set any codes. Neither will low fuel pressure. No pressure sensor on the rail.

Easy way to test the pump. Open the fuel cap, turn key ON. You should hear the pump turn on for 2 seconds then shut off.

There is also a jumper connector under the hood that you can jump to power the pump.

On a P/U the easy way to change the pump is to pull the box off. Less aggravation that way. Then you can clean around the pump, replace the pump module and change the pigtail all at once.

Oh and if at all possible use an OEM pump. Some of the after market units are CRAP...

I would stick a FP gauge on the test port first. Anything under 55 PSI and the pump or regulator is suspect.

Reply to
Steve W.

I took the regulator off and turned the key ON hoping to see gas shoot out. Nothing.

I removed the bolts holding the bed on the driver side and loosened the bolts on the passenger side, then lifted the driver side and placed blocks under it. The pump comes out reasonably easy.

Reply to
Jeff Strickland

My gut sense, is that you're a kind neighbor. And that the woman who owns the truck doesn't have a lot of money. If my people sense is correct, you're a very kind fellow. And she is very fortunate to have a good man like you for a neighbor. You must be American?

Reply to
Stormin Mormon

That sounds like real advice. The mechanic who did the fuel pump on my van also suggested Delco original equipment. Same deal, the after market pumps are poor quality.

Reply to
Stormin Mormon

That works just as well. The big advantage over dropping the tank is that the pump is right there at a nice working height. You can get to the wiring and the connections really easy.

When you install the new pump put a thin coat of grease on the retainer. Keeps it from rotting out and allows it to seat better.

Reply to
Steve W.

Not a trouble code but; Long term and short term fuel trim. Often times, when the vehicle is still running, the long term and short term fuel trims will be higher than normal. Naturally, the specific cause needs to be verified.

There is no such thing as "OBD I." OBD II is an emissions standard that specifies the monitoring of certain components for (potentially) excessive emissions. A vehicle that doesn't run because of a dead fuel pump can not create excessive emissions.

Reply to
aarcuda69062

And if it did and there was even (there always is) the smallest spark from a relay or the starter solenoid...

No need to call the fire department then...

If you're going to play mechanic, please think responsibly.

1978, at the Chrysler-Plymouth dealership that I worked at, a mechanic had splashed a little gasoline down the carburetor of a no start car, the engine back-fired, the mechanic was engulfed in flames. He spent many months in the burn ward. When he finally returned to work he had to wear special nylon coverings on his head, arms and hands. Just the thought of having to wear that stuff in summer should give anyone pause to think when doing foolish things with gasoline.
Reply to
aarcuda69062

I'm not that dumb. Close, but not quite. I turned the key to RUN, not START. The pump ought to have come on if it was going to.

Reply to
Jeff Strickland

OBD I is the predecessor to OBD II. It lasted from (about) 1981 until 1995 production. The trouble with OBD I is why we have OBD II. The problem was that the earlier system had different implementations across all car makes and models, so the service providers had to learn lots of stuff and keep lots of equipment that cost lots of money so they charged lots of fees just to tell you what was broken, then started a whole new charge basis to fix it.

Guys at home, like you and I, could not test for ourselves the common kinds of problems because the diagnostic data was not readily available or accessable. OBD II standaradized the data and the means of extracting it.

In any case, my '95 Bronco started and then died one morning. I happened to have a code reader that worked on Ford, and it told me the fuel pump was dead. I don't know how it knew, but I'd guess that it looked at the current flow in the circuit and could tell that something was wrong. Obviously the options would be bad wires or defective motor. Assuming the wires are always good, the motor is the only remaining failure point. Not rocket science.

There are codes in the OBD II scheme that cover the fuel pump circuit, P0230 ~ P0233, but these apparently do not do what I was thinking they should do.

Thanks though, I found the pump right where I expected it to be.

Reply to
Jeff Strickland

There is no such thing as OBD I. There is no SAE standard for OBD I as there is for OBD II.

There wasn't even a requirement to illuminate the check engine light during that time frame.

There was no trouble prior to OBD II. People ignore the check engine light on OBD II vehicles just the same as they did in 1982.

No different than vehicles produced in 1996 and later.

Still happening. :-)

I'm not a guy at home.

Never had that problem.

Funny, my IDS works most excellently on Ford products but works like crap on GM cars. My Tech 2 works great on GM vehicles but works like crap on Fords. My Snap-On Solus Pro requires 20 some odd different personality keys to properly function on the various vehicles that it covers. My Auto Enginuity wants me to choose from a half dozen communication protocols before it will connect to a module. My DRB III works extremely well on pre-CAN Chrysler products and yes, for some strange reason, it will allow one to connect via generic OBD II but why on gods green earth would I want to? I own something like seven scan tools, I could go on... The mandated OBD II communication baud rate is on par with what GM used in 1982 on the MIn-T systems used on Chevy Chevettes.

Nothing is standardized except for the absolute minimal basic data and the lay out of the DCL but that in itself doesn't preclude numerous variations.

There are/were only two fuel pump codes for a 1995 Bronco, neither one will pin-point a 'dead" fuel pump. Code 543; Fuel pump circuit open PCM to motor ground Code 543; Fuel pump circuit open battery+ to PCM

Ford ran a diagnostic wire from near the inertia switch back to the PCM, this circuit is called "fuel pump monitor." All it does is monitor available voltage to the inertia switch/fuel pump. it makes certain assumptions, proof being that the open ground trouble code can also be cause by a short to power in the fuel pump voltage feed wire, a short to power in the O2 heater circuit, the fuel pump relay contacts being stuck closed. All it looks for is a change in voltage as would happen when a fuel pump powers up.

It didn't know. it could have been any one (or more) of a half dozen faults not all of which apply to a "dead" fuel pump.

Nope, it just looks for a change of state in voltage in the B+ feed wire to the pump.

Why would you assume that the wires are good?

The only one of those that applies to this truck is the P0230, but it won't set if engine speed is under 600 RPM.

If you don't learn it from me, maybe someday you'll realize on your own that OBD II is not the silver bullet you hope it to be.

Reply to
aarcuda69062

Just went through this same procedure - raised the bed and replaced it from up top - not easy dropping it when you just gassed up and have 22 gallons in there!

Bingo on the fuel pump aftermarket crap. I checked all the usual outlets and the BEST price for Delco OEM was AMAZON.COM would ya believe? Much less than NAPA or even Rockauto.com.

Word of warning though - the retainer ring really got messed up trying to get it loose to pull the pump (and it was rusted to hell besides) - had a helluva time finding one locally and it did NOT come with the kit - ended up at the Chevy dealer and got gouged for almost 20 bucks for a cheap stamped piece of steel - but hey, it went on like a charm!

Good luck!

Reply to
Dave Klees

I would have never thought of Amazon. And yes, twenty bucks sounds a bit much for a stamped piece of metal.

Reply to
Stormin Mormon

Hi!

I won't say there isn't one, but I haven't heard of it. Your experience with OBD I on a Bronco is interesting.

Of course, there was some variance there. I've got a Plymouth Reliant station wagon that will set a code and turn on the engine light if the battery is (exceptionally) bad.

Yes, it is.

Will a bad fuel pump keep this truck from running? Absolutely and beyond any doubt. It's likely that the pump is the problem, but you might also check the relay and the fuse to be sure that both are good.

(Although, if the fuse blew, it had to blow for a reason. I have a '94 Chevy truck that started blowing fuel pump fuses completely at random one day. It'd be fine for the longest time and then the fuse would pop. The fuel gauge didn't work either. At the time, I failed to connect the two. And then the pump died, so I had to pull it. Off came the bed and out came the pump. And right there was the reason why the pump blew fuses from time to time and the gauge didn't work. The float arm had broken off and was, well, floating around in the tank. Every now and then it would brush into the terminals on the pump and pop the fuse. This also confirmed something else--someone once said that the electric fuel pump being in the tank was not a big problem because the environment was far too rich to support combustion. Apparently they were right--or I suspect the spark made each time the pump got shorted out would have ignited the tank and set it off like a bomb.)

You can do the pump two ways--the easy one and the hard one. The easy way is to remove the bed and haul it off with a loader tractor or several guys who are stout enough to walk it away. The hard way is to do it from underneath and drop the tank. You'll see the pump right away if you take the bed off, and one big advantage is being able to sit down and work on it easily.

William

Reply to
William R. Walsh

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