LBGSHI

Ah, good point. I haven't heard any squealing.

However, when I removed the belt a few days ago (when I was concerned that the engine might have been seized, when in fact the new starter was bad), I noticed that I could only turn a few of the pulleys by hand for more than an inch or so. I guess I could pull the belt, and try again, noting which pulleys resist.

LBGSHI

Well, I replaced the fuel pump. The new one I got, from Airtex (Advance Auto didn't have Bosch in stock), is the correct pump, but came with the wrong manual (a manual for an in-tank pump). I figured, no problem, I'll just install it like the old one, wiring toward the engine.

After installing the pump, verifying polarity, and securing the fuel lines, I tried to start the car. It cranked just fine, but no combustion...no sputtering, nothing. I turned the key off and on about twenty times to see if it just needed to have some fuel forced up to the fuel injectors...still nothing. I depressed the pin on the fuel rail Schrader valve, and there was no pressure...not a sound.

I looked the pump up online, and it turns out that this pump has its wiring toward the fuel tank. I'd installed the pump backward, and I assume that means I'd been pumping fuel from the engine to the fuel tank.

I removed the pump, installed it correctly, and tried again...still nothing. Turned the key on and off another twenty times, and still nothing. I depressed the pin on the Schrader valve again, and this time, I got some pressure, but it doesn't seem like much...probably not even enough to register on a pressure gauge.

I've tried reinstalling the old pump, and following the same steps, but still, nothing.

I pulled the plugs, and I don't see any gasoline on them. Is there anything obvious I need to do? Did running the pump in reverse screw something up? Do I need to release pressure on the return line or something?

A nudge in the right direction would be very appreciated.

kc0rey

Do you have power at the pump?
It sounds like you got the wrong pump.

Advanced auto sucks. Do you have a NAPA close by?

I learned my lesson about the discount auto parts houses. NAPA Is the only place shop at now.

LBGSHI

I can hear the pump engaging when I turn the key to On, and it seems to sound better than the old pump (more of a healthy whine than the old, low whine of the old one). Still, if they gave me the wrong manual with the pump, it's always possible they gave me the wrong pump for my truck as well. But then, reinstalling the old pump should work.

There're a NAPA around here somewhere.

Any other quick things I can check in the fuel system for a hint at what's going wrong?

I pulled the return line from the fuel tank selector valve, and no fuel came out. I'm not sure if it should or not...

351W1085

I think the low pressure in tank pump is bad. Your truck has a 2 pump system where a low pressure pump pumps gas up to the high pressure pump, forcing it into the injectors. it sounds like the high pressure pump is trying to suck gas all the way through the bad low pressure pump all the way up to it, which it was not designed to do. I'd replace the low pressure pump inside the tank and see what happens. If that doesn't work, which i'm sure it will, then the fuel selector valve may be plugged up or something else wrong with it. Also, have you replaced the fuel filter yet?

LBGSHI

That would be a good hypothesis, but I have two tanks, and previously, both were working fine. I've tried using each tank since this most recent problem, but no dice. It's highly unlikely that both in-pump tanks failed at once.

Yep, I've replaced the fuel filter as well.

LBGSHI

*intank pumps. Heh.

kc0rey

You can test that. Disconnect the line that feeds the high pressure pump. Run that down to a glass or see through container. Have a helper turn the key on until you see gas. If you see gas you at least know the pump is working and at the same time you will see if there is any dirt or water in your system.

LBGSHI

Heh, before I read your last post, I tried that exact thing. I noticed that I got almost no fuel (just bubbles and mist) coming out of the high pressure fuel pump, whether the key was turned to On or the car was actually being started. Switching between tanks made no difference. After swapping the old pump back in, I got SOME fuel when the key was turned to On (a weak dribble), and a weak spit of fuel when the car was starting. I looked up reviews for the new pump (Airtex brand), and found a lot of bad ones...not working out of the box, etc. I took the new pump back to Advance Auto, returned it for a refund, drove to the next Advance Auto about ten minutes away, bought the last Bosch OEM pump they had, and after cutting/stripping/reinstalling the wiring (sucks that the crappy pump at least came with all the adapters I needed, while the Bosch didn't), I performed the same test. Fuel shot out like crazy.

I sprayed some starter fluid into the intake to help the engine start cleanly, and it sure did. I pulled it in and out of the parking spot a few times, testing out all the gears, and it felt and sounded great. I drove it around the parking lot, and finally took it to the gas station on the corner and filled up the rear tank with 87 octane fuel.

It looks like the exhaust manifold was causing those popping/chug-chug-chug sounds and backfire feeling, and the high pressure fuel pump was causing the stumbling and dying in low idle.

Here's something interesting: when we bought the truck, it was using the rear tank, and was almost empty. I mistakenly filled up the front tank (which was already half full), not realizing the truck had two tanks, and was confused as to why the gauge didn't show the existing fuel, or the new fuel (bad gauge, I thought). I later discovered that there were two tanks, and switched to the front tank, which had the 93 octane fuel I'd just added, with a can of seafoam in it. My step-daughter drove it for a day or two, and then it died, never to return to normal operation until after all the work I've done in the last couple weeks (in this thread).

Now that the truck is running, I noticed that if I switch to the front fuel tank, it runs more weakly and stumbles a little. It even died after a minute or so of low idle while I was outside the car looking for leaks, etc.

So, I figure, either the front tank had some contaminants, bad fuel, etc...or the in-tank fuel pump in the front tank is going out, and forcing the high pressure fuel pump to work too hard (and it possibly burned out the fuel pump, twice). I suppose it's also possible that the truck just hates 93 octane fuel...

Any last tips for testing each in-tank fuel pump, or should I just drain the front fuel tank, clean it out with something, put in a couple gallons of 87 octane, and try again? I don't want to kill my new Bosch pump!

Now to deduce the issue with the power steering pressure switch/leak, the dash lights that don't work (but did for the first two days we owned the truck), the indicators that have suddenly decided to work very slowly (5 seconds per blink or so...could be that I bumped a fuse in the fuse box when I was looking for the fuel pump relay that turned out to be under the hood), replace the tattered seat belts, and replace the R12 AC system with an R134a one. Any tips on those would be appreciated as always, but if I get confused or want a more detailed nudge or two, I'll open a separate thread to keep things simple.

Finally, thanks very much for all your help. I really appreciate it.

kc0rey

Starting Fluid, even a little, = BAD NEWS! Throw it away! You can test the fuel pressure (with a gauge) while running on the tank with the suspect pump. I'd do that before I did anything. As for the 93 Octane, run it for now and add 87 to it when you get low. A few tankfuls and it will be gone.