Will running out of fuel damage a DS4?
I know many of you have been following my saga of fuel supply issues on my '95 Tahoe.
Two days ago, I left for work, only to have fuel starvation again. I turned around to head back home, but the engine stalled twice due to running out of fuel. In hopes of trying to make it back home, and being a bit aggravated, I pushed the throttle farther and farther as she ran slower and slower. The last mile or so she she gradually slowed down as she starved for fuel. She finally died and I coasted to the shoulder. I tried to bleed the fuel system again, but gave up and called for a tow.
Once I got her home, I tried to start her up to pull into the garage. I bled the filter, but she wouldn't start without a lot of cranking, which I expected. However, she finally started up but ran terrible and smoked like a freight train. I have never seen so much smoke! She wouldn't clear up, so I pulled it in and shut her down.
I finally had a chance to get back to her tonight. I've got good fuel pressure at the filter again, and I've bled the system, but she won't run right. She takes lots and lots of cranking to even fire, and then it takes a little throttle input to keep running, and at the same time she's smoking something terrible and shaking the whole truck. It's like the timing is way off.
I made sure I had fuel to the IP, and even took the return line off the top of the pump. I started her back up, and I must admit I was quite surprised how much fuel came out of the IP! She squirted fuel out past the radiator. I put a clear hose on her, and she's got steady fuel coming out when running (running badly, that is). I'm not sure how much fuel flow is normal, but I'd say about a quart of fuel came out of the IP in less than a minute. Just to make sure, I swapped out the check valve on top of the pump with another one I had from a spare DS4 with no change. It's funny, in 17 years of 6.2/6.5 ownership, I have never actually ran an engine with the return line loose from the pump, so I don't know what is normal flow in the return system.
I swapped on my good PMD spare, but no change.
I then took the filter harness off the pump, but no change.
I then removed the top of the pump to look inside, but nothing looked out of the ordinary.
I had replaced the optic sensor a couple of years ago. Just for giggles I loosened it up and turned it towards the driver's side and tried starting it. No change. Next I adjusted it to the passenger side, and she started a little easier, but not much better.
In comparing the optic sensor in my IP with the other DS4 I have, I noticed that my optic sensor is easy to move from side to side, but the other pump seems to be spring loaded and wants to stay towards the driver's side of the pump. I'm not sure if that matters or not.
So I'm pretty stumped now. I can't imagine what I may have done by pushing her too long with too little of fuel, but I did something. Any ideas what to do next? I don't really want to start throwing parts at her....I'd like to have an idea what could be the culprit.
Thanks,
Casey
