Probably have ignition issue or bad gas

[Rexxenexx]

Finally gave up the ghost while I was getting stuff from an Amazon Locker.
The day before it fell asleep while I was turning left at a light. Started right up after I put it in Park and cranked it again. Checked everything. All fluids perfect. oil at hash, looks clean. Trans at mark while running. 12.8v at the battery (in back) off. 12.8v at alt. lug. Tightened the neg terminal just for shits, it felt looser than the positive.
Next day (today) seemed OK. drove across town to pickup stuff. Came out, turned the key, idled for around 5 sec then progressively puttered down til dead. Tried again, same thing but a bit shorter. then shorter. Now it just cranks. I checked fuel pump fuse at alt. (Racetronix kit). Pulled and reseated coil/coil wire terms. Tried pulling the water temp plug.
Couldn't come at a worse time. In an Austin hotel for a couple days so I'm having it towed to a random shop. So I expect it to be stolen tonight lol jk. Once they find out what was the prob I'll update.
Edit: Now that I'm at my hotel I'll elaborate. Checked gas cap, fine. checked vac hoses, even ones to evap, all good. The Ty's been good since a fan clutch change, literally just filled up at a nice looking Texaco and that KO on a left turn yesterday happened a couple miles away. Even drove normal on the way to the Amazon locker today thats why Im thinking most likely not shit gas and it didnt hesitate driving like a pump dying. If I remember correctly, similar issue with the other Ty I had turned out to be the ignition module. I hate not having my garage and tools. The place I dropped it off at looked OK. Classic cars and good-old-boys. Wish me luck!

 

[BMFB]

id bet fuel pump still. Interested to hear what they came up with.

 

[Rexxenexx]

Could be. Pump is an Aeronotive Stealth 11569 that I put in @22K miles on the od. I think I'm a bit over 46K now.

 

[2500avalanche]

Since voltage is good, that narrows it down. I would guess a pump. If you think about it, you just filled it up. Maybe it (for some reason) changed the work load of the pump. Also, do you think the fuel filter? Thinking of cheaper things first...

 

[Rexxenexx]

As long as the pre-filter on the pump is still on, the filter should be good. It's the AEM donger filter, installed same time as the pump.

They should be looking at the Ty today.

 

[BMFB]

I had one of those filters plug up on me faster than I thought one could. The filter size is no where near as big as the stock one (if its the same sorta metal screen deal I had)

 

[Rexxenexx]

I think he said oil pressure sensor/switch AND fuel pump. They're working on it now and I don't get it until monday.

Funny thing is, after all these miles on two road trips I decided to get some stuff from Sportmachines. window trim, seals, full Trans cooler w lines, wheel orings kit, swaybar bushings. And it took a celebratory dump right after Phahhaha. At least it did it while I was parked.

Update: I now own a house *duhdum chshh*. Hopefully they do a good job and the Ty can be reliable until I ship my tools here. I'm working on building a new workstation and buying a good high temp 3D printer.

 

[BMFB]

im pretty sure the oil pressure switch thing is a scam. I do no believe it interferes with pump activity. I tried to find a schematic to see if I was right and all I could find was a doc where the pressure switch was in parallel with the relay. Be interested to get corrected on this one.

I would swap that filter out with a stock style filter. You do not really need to worry about debris getting in beyond what the stock filter was capable of dealing with. It is possible that the new filter was harder on the pump as well. If you plan to run E85 there is a filter that swaps in from like a 2007 flex fuel avalanche.

High temp 3D printing is cool. Get them tools close to you, your driving a typhoon.

act like it

 

[Rexxenexx]

Roger. I don't see oil pressure anything on the bill. Just new FSU and Misc. I'm back at the shop from picking it up. We're right now looking for the fuel rail aluminum cap which he dropped and replaced it with a small plastic one that couldn't get more than one thread. I immediately saw it when I stopped for gas and checked the engine bay. I hate little things like that. Anyways, the FSU is so sensitive compared to the one I had before seems like. It was almost at empty maybe that's why.
The pump melted the connector on the FSU. Maybe a Walbro and figure out an AN line to stock filter adapter like you're saying. He showed me the NAPA filter came with a wrong size oring. Not good.

Here's the bill:

 

[BMFB]

Your alright

The melted bulkhead wire is pretty common. Its just a cast piece of plastic with 4 metal strips hardset into it that flow the current for the pump and float sensor. Your 3d printing skillz may help you with this one day to remake a better one with thicker strips. Cooler fuel pumps flow more current, more current makes those things melt quick.

When I had this happen to me I ended up drilling the connector out completely and running wires directly into the tank through the hole id made and then gluing them in with quicksteel fuel tank epoxy. Been 14 years on that one without repercussions yet...

If your running a stock pump setup you should be good for quite some time. If you run into a weird issue where the fp's keep dying prematurely look at that bulkhead before you swap another pump in.

 

[RealFastV6]

im pretty sure the oil pressure switch thing is a scam. I do no believe it interferes with pump activity. I tried to find a schematic to see if I was right and all I could find was a doc where the pressure switch was in parallel with the relay. Be interested to get corrected on this one.

I would swap that filter out with a stock style filter. You do not really need to worry about debris getting in beyond what the stock filter was capable of dealing with. It is possible that the new filter was harder on the pump as well. If you plan to run E85 there is a filter that swaps in from like a 2007 flex fuel avalanche.

High temp 3D printing is cool. Get them tools close to you, your driving a typhoon.

act like it

It's wired in parallel but I don't recall the intended function, I just remember removing the oil pressure switch function when I installed the XFI in the Syclone.

Circuit 31 coming out of the oil pressure switch is the actual pressure signal for the dash.

Circuit 440 (12v pos) and 120 (12v pos) both connect to the fuel pump relay.

Circuit 440 (12v pos) and 120 (12v pos) both connect to oil pressure switch.

Circuit 440 (12v pos) is the power supply into the fuel pump circuit from the fuse box.

Circuit 465 (12v pos) is the connection from the ECU to the fuel pressure relay to excite the relay. (I know people say ignition module sometimes, which is one of the conditions that the ECU uses to excite the relay, but ultimately it's the ECU.)

Circuit 450 is the common system ground that the relay uses.

Circuit 120 (12v pos) is the feed to the fuel pump, which can get power from potentially 3 sources...

Source 1 - Oil Pressure Switch
Source 2 - Fuel Pump Relay
Source 3 - The Fuel Pump Prime connector

I don't recall the intended function, but the wiring diagram indicates parallel operation.

I see OP has one, but I'll soapbox about the fuel pump wiring for a minute while I'm thinking about it for anybody else reading this. People should realize how small some of these fuel pump circuit wires are. When an aftermarket fuel pump has poor voltage because of the size and length of the wires, it's going to draw more current, which is going to heat things up and damage them. (Pump, wires, relay, oil pressure sending switch...). The fuel pump circuit has 14ga wiring for some parts of it, but then other parts of the circuit are as small as 18ga. 14ga all the way through would be about the bare minimum requirement for a Walbro 255 for instance. If you're going to put an aftermarket pump in these trucks you really ought to put a hotwire kit in there too like the Racetronics. It's plug and play, and doesn't modify the factory wiring, and it just turns the factory feed into the excitement circuit for a new relay which is fed directly off the alternator. I wonder if all the people complaining about the 3 year life of fuel pumps are running factory fuel pump wiring.

 

[BMFB]

In the circuit I found in my s10 haynes manual shows the oil pressure switch and relay being in parallel like you said. The way it would work (as pictured, reality could be different (lol)) is after there is oil pressure you could remove the relay and the FP would still get power to run until the engine is shut off. OR if the relay was totally gone you could crank your engine and make enough oil pressure to switch the FP on.

You are super right about draw with aftermarket FP's and the effects of heavier draw on the stock wiring. The weakest and firstest thing I say to replace is the bulkhead connector and wires in the tank.

 

[RealFastV6]

I just looked up that 11569 pump, I didn't realize that's the 340 pump. They recommend 10GA wiring.

She's a big girl.

 

[Rexxenexx]

Yep. It had the Racetronix kit and the pigtail the Aeromotive came with repinned to the bulkhead connector instead of crimped on the original little wires. I'm sure it's crimped on now. I don't believe these guys had attention to that detail.
I haven't had any luck the last two times with Walbro 255HP. Both times the little hose they included blew. I tried getting from recommended reputable dealers, but maybe they were fake kits. So I decided to try something different.

 

[BMFB]

what about the bulkhead itself? Did you leave it stock?

 

[EastCoastBubba]

@DaveP's Ghost might know about this oil pressure sending unit stuff if he's still around.

 

[Rexxenexx]

Here are some pics of my install modifying the bulkhead connector when I installed the 1st Aeromotive:


I'm thinking of getting the full Racetronix kit and a new OEM FSU, keep it in the closet for the next time. My Racetronix wire relay upgrade is REAL old. Before they sold their own branded pumps old. Good insurance to replace it next time.
Also, I think the float on whatever FSU they installed is clocked towards the front. Because every time I go, the gauge drops to almost empty when I'm half a tank. The float should be left or right not front back right? I don't see any other logical reason its so sensitive, even though it's keyed so you can't F up.

 

[BMFB]

the wire upgrade stuff should be fine until the insulation is cracking off, im interested to hear what its doing thats got you spooked.

Its been a while since iv been in a tank like that, but those look like the connections in the tank. The square connector plugs into the bulkhead on the inside of the tank and yours looks good. The issues I always had were with the bulkhead itself and is part of the sending unit. They are tiny metal leads set in plastic through the tank which I drilled out and ran wires straight through cause I couldnt find a better way at the time.

 

[Rexxenexx]

The square connector in the pic is the one that melted. It looked like one corner burned (bulged and black). I should have taken a picture of the burned one. I can't remember the corner otherwise we could compare and see which wire got hot. Either way, this pump shouldn't be wired through a stock bulkhead. The day long runs through extreme heat going state to state didn't help either.
Running the wires through is a good idea, but you just need to do it in a way that vapors don't leak out.

 

[BMFB]

alright

ya i drilled the hole a bit bigger than I needed and gooped it on both sides with quicksteel fuel tank epoxy. So far so good, been about 15 years