No power, stall, now won't start

[keithhoffman22]

Hi,

This is my first post. I've been reading lots of threads about problems with fuel and not starting but am not sure after reading all of these posts what approach to take so here's my story. Any help is very appreciated!

Yesterday, I took my subbie out to head for a run in the am. She has hesitated out of the driveway for a long time but this time it didn't go away by the end of the block as usual. I should have turned around but I was hoping it would go away. She came up to 45 mph on the first acceleration but on the next block she struggled. At the next rise (overpass), she won't go 25 then progressively stalled. After stalling, she wouldn't restart.

I futzed with the problem a bit yesterday but didn't really get anywhere. Here's what I did:

Replace fuel filter:
- First, I didn't think the fuel filter had been changed in a long time. So I ran home, got the other car, got a filter, and installed it on the side of the road. It was tough to get the hosing loose so I think it was indeed old. There was some fuel in the line but very little. I had done the fuel cap off and crank trick to try to depressurize the fuel lines. Tried to start after replacing the fuel filter. Strong turnover but no dice.

Attempted to Diagnose Fuel Pump
- Next, I picked up an after market fuel pump thinking that was next. I haven't installed it yet. Keep reading. I did the key into ON and listen for a whirr on the open gas fill tube. No whirr. I also tested for power on the harness at the fuel pump. I got 12V off the middle top pin crossed with the lower left (if you are look at the pins) or the lower middle. I got odd voltages across the right two pins (blue lines). I assume those are fuel level pins. At the time, I thought this meant the pump had power. I think this voltage was constant when the key was in the ON position but I guess I'm not 100% sure of that. FYI, I did try cranking as well. So I don't think I saw voltage at all (on or cranking) on pins top left and lower lower.
- Next I pulled the existing pump. Strainer looked fine, fyi. Since I could now see which power pins were associated with the fuel pump, I realized that that upper left pin should 12v on it when the pump should be running. Since I was no longer convinced I had voltage to the pump and therefore it might be good, I reinstalled it. Why not just replace it? A) cost B) I've replaced original parts with aftermarket before and had the aftermarket be worse new than the original so ... It's worth noting that there was a little fuel in the delivery line from the pump when I pulled it. Not much. I had done the depressurization step.
- The aftermarket I have (returnable) is a NAPA labeled Carter that is smaller and requires modifying the wiring of the fuel pump assembly. I can get the same pump from napa that is currently in there (original) for $150 more.

Confused about when the fuel pump should receive voltage:
- So now I'm confused about when the pump should receive voltage. From reading other posts, it seems like I should see voltage to the pump when the key is ON but that voltage might not be constant. It definitely seems like I should see voltage when cranking.
- Since it seemed like the voltage was possibly not right, I picked up a new fuel pump relay but have not yet installed it (I couldn't safely do it on the side of the freeway since it requires under dash work on the drivers side.

All of the above diagnosis occurred on the side of the freeway in the hot sun while huffing too much gas while pulling and reinstalling the fuel pump so I'm open to my volt meter work needing restesting.

After all that frustration, I took advantage of that offer to join AAA that was sitting on the counter at home and had it towed home. Right now, the battery is charging (I pretty much killed it cranking the engine for various tests) and then I'm going back at this so any advice is appreciated.

Barring wisdom from this list, I'm going to do the following:
- Retest the voltage to the pump across the top left pin and the lower left pin with the key ON and during cranking.
- Try to figure out how to get to the fuel pump relay and try to see if it has 12V supply to (no idea which pins but if the voltage is constant that should be easy...)
- If there isn't voltage at the pump and there is voltage at the relay, I'll replace the relay.
- If there is voltage at the pump after all, I'll replace it.
- If I can't figure anything out and everyone on this forum is enjoying their sunday instead of reading the internet, I'll replace them both. While I'd rather do this right, at ~$125, it's a lot cheaper than the shop charge.

Other stuff to mention:
- Other than the momentary hesitation out of the driveway that has been long-term, this problem is rather sudden. She was running strong at 75 mph on the freeway on Friday and uphill at elevation last weekend without issue.
- Check engine light is off. I don't have a reader.
- I haven't looked at or tested the crankshaft sensor, the camshaft sensor or the fuel pressure regulator. Local shop has the FPR in stock but it is $150+. Don't know about the sensors.
- I guess in the end I don't know this is fuel for sure but without a check engine light, ignition malfunction seems unlikely?

Car History:
- 280k on the odometer, I've had her since 208k. New engine and usual list of related stuff at 165k.
- The timing belt, idlers, and tensioners were all professionally replaced (Suparupair, which is off-and-on a good shop) ~10k ago, along with oil sender, and cam seals (that was a big bill... wish I had done it myself). The plugs were done shortly before that. Wires are considerably older (60k ago) but there hasn't been any sign of issue there and the replacements were factory. Shop did the plugs and said the wires were fine.
- Battery is pretty fresh. Alternator is unknown age but I haven't had issues.
- Coil pack was replaced with a used coil pack ~220k.
- I don't have a fuel pressure regulator and a T hasn't been installed.

Sorry, this post is so long. Based on the other fuel related posts, I read on this forum it seemed like more info was better than too little.

Since it is so long, here are my specific questions:
- Should I see voltage constantly to the pump with the ignition switch in ON?
- Should I see voltage constantly to the pump when cranking?
- Anyone know for sure that pins TopLeft and LowerLeft are correct for the fuel pump power?
- Any suggestions how to test the relay? I'm a little confused about how to know if it is bad other than (if power at relay && no power at pump during cranking) { replace relay}

Thanks so much for reading all of this!

Keith

[keithhoffman22]

Voltage re-test:
Ok, I don't know if it was the heat, gas, or freeway noise, but this time when I tested the voltage on the harness to the fuel pump, I saw ~12V during cranking on the top left and lower left pins (presumed delivery to the fuel pump). I didn't see any voltage with the key in the ON position (even in the first couple seconds) which makes me suspicious about that ON and listen for the whirr test I've read about. Anyone actually heard the whirr or know if I should see voltage on those pins when the switch is on?

Barring helpful info, I guess I'll replace the pump this evening when it cools off. Any opinions on OEM vs the aftermarket smaller Carter pump?

Occam's razor corollary:
All other things being equal, the explanation that relies on your own stupidity is probably the right explanation.

[BoarderM]

That's exactly what happened to me. My car became progressively slower and was unresponsive to the gas pedal. It finally stalled on the side of the highway and wouldn't start. I had it towed to my dealership and it turned out to be a faulty fuel pump. As for the fuel pump whirr, yes you can hear it clearly sitting in the drivers seat if you turn off the fan and radio. When you turn the key to it's last position, right before cranking, you can hear the whirr coming from the back seat for about a second.