Just because you haven't had a problem doesn't mean it isn't an issue, we all know air in fuel is hard on pumps and injectors why risk it
LB7: Fuel milage
- Thread starter Jacob tomlinson
- Start date
Just because you haven't had a problem doesn't mean it isn't an issue, we all know air in fuel is hard on pumps and injectors why risk it
Well, the OP hasn't come back with any hand-calculated mileage, I thought the consensus was that this was in the realm of reasonable for winter fuel? Not much more we can do for him there.
Clearly we don't all know, I'm that one asshat that questions everything. :hug: I do run lift pumps (mostly to mitigate the constant air leaks from the factory filter head-- talk about introducing air!). But if it was that dangerous to go below 5 gallons, GM would've made the low fuel light come on sooner. I don't recall reading anything in the owners manual saying "always fill up before 1/4 tank"
I'm with DAVe on this one.
I dont think the engine would run long enough when out of fuel to cause any wear or damage to the pump and the injectors operate on pressure so would quit the moment the fuel pressure stopped
Yeah, I guess there could be a chance that you could run out of fuel at speed and coast to a stop which would continue to turn over the engine and thus the CP3. But... How could this be any worse then trying to start engine and prime the fuel system and turning the engine over a bunch. We dont hear of damage from this.
And it is not likely anything to do with cooler fuel as the fuel is pulled and returned to a bowl in the sender so the hot fuel is getting sucked right back in constantly
These CP3s are quite robust. A CP4 on the other hand...
I dont think the engine would run long enough when out of fuel to cause any wear or damage to the pump and the injectors operate on pressure so would quit the moment the fuel pressure stopped
Yeah, I guess there could be a chance that you could run out of fuel at speed and coast to a stop which would continue to turn over the engine and thus the CP3. But... How could this be any worse then trying to start engine and prime the fuel system and turning the engine over a bunch. We dont hear of damage from this.
And it is not likely anything to do with cooler fuel as the fuel is pulled and returned to a bowl in the sender so the hot fuel is getting sucked right back in constantly
These CP3s are quite robust. A CP4 on the other hand...
If you live in an oven in the summer then you aren't really doing yourself any favors running it to emptyas as far as performance goes. Cycling a small amount of fuel to a hot engine with extreme asphalt temps doesn't allow much cooling.
Like I said before, I cant see having a 1/4 tank or more is going to help much on cooling the fuel when the return gets pumped right back into the bowl that the pickup is located in.
Sure some mixing of the fresh fuel is going to happen but is it really going to be enough to make a big difference in the life of the fuel pump?
Sure some mixing of the fresh fuel is going to happen but is it really going to be enough to make a big difference in the life of the fuel pump?
Fuel temps do rise a bit as your tank gets lower, but nothing crazy. From all the miles I put on my truck towing, empty, etc. and seeing the fuel temps, I didn't even install a fuel cooler when I did my Duraburb. It sees almost identical temperatures to the truck despite no cooler.
There was a big thread a while back about fuel temps and mileage, and some people said they saw a difference with cooler fuel temps, but really just a bunch of theory and claims. I don't think anyone ever put in the work to prove it out. I suppose I could put a cooler on my Suburban and see if my MPG goes up, but that would take thousands of miles to get a good feel for it, and if I was too lazy to install one with the body off, I sure ain't installing one now :baby:
There was a big thread a while back about fuel temps and mileage, and some people said they saw a difference with cooler fuel temps, but really just a bunch of theory and claims. I don't think anyone ever put in the work to prove it out. I suppose I could put a cooler on my Suburban and see if my MPG goes up, but that would take thousands of miles to get a good feel for it, and if I was too lazy to install one with the body off, I sure ain't installing one now :baby:
Mike proved a cooler does help immensely. Dunno where it was but someone posted that the inside of an LML tank had melted from hot fuel on a high hp truck, which ifcorse the LML doesn't come with a cooler. It's already been proven by scientists, engineers and racers that cooler fuel is more energy efficient in all aspects.
Jacob , is your truck still running or did something let loose to tell you where the grinding noise was coming from , keep us up to date ! Someone here way have some good advice !
As of roght now i am still chasing this noise, im going to check the parking break and see if it came loose in the wheel?? My parking break barely holds so maybe thats it!
Parking brakes ain’t very good in these trucks to start with, but worth a look.
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Do you have a carrier bearing ? That is why I wanted to know if it is a long bed CC ! They are known to make noise upon light acceleration ! Did you check all the U joints ? Did you push straight up and down on T case output yoke ? Did you drain the $8 worth of T case fluid into your wifes clean white tupperware container , to let us know weather it is full of metal chunks ? You said the T case is full but leaks , so if thats the case the fluid is coming from the tranny seal which you can replace when you do the pump rub kit !