Fuel starvation problems going uphill?

[musigenesis]

Originally Posted by cadillackid

I do 6k milkes for oil and 3k miles for filter on my diesels.. so one filter change in the middle between oil changes...

I'm guessing for you the time between changes is never relevant.

[musigenesis]

Originally Posted by CHEESE_WAGON

Attachment 49643

Well, this was the correct meme to post. It's a bit more than what you stated (they quoted me $2K for the parts) but they're also going to do an oil change and all the filters, including the coolant filter with the silicate additives.

On the plus side, the mechanic fixed my clearance lights (gratis) by plugging a loose plug back in to the CL switch, so apparently it had already come loose from the switch and I had never noticed it. Fixing a school bus is so easy!

[lemmeskoolu]

Originally Posted by musigenesis

Well, I was at least able to make the four miles to the shop this morning. Weirdly, the bus wouldn't start this morning (first time since my new starter that it hasn't fired right up). I hit the hand primer some more but now I'm not even sure it's working correctly - I just keep pushing with the same amount of light resistance and it never gets harder to push. Anyway, the engine started up after doing that and I was able to limp up the couple of hills I had to go over, although again the power was cutting out if I got over 1500 RPM or so. The WARN ENGINE light came again during the second hill.

After the hills there's a two-mile straight run and it seemed like the problem cleared itself again and I was able to rev over 2100 and still get normal power.

Anyhoo, it's in the mechanic's hands now so hopefully this won't be too grisly in terms of wallet damage.

Call Tony at AAA Bus, LlC in PHX let him know Tee from NJ referred you, he has parts at reasonable prices and also a bus mechanic!! +16022789339

[lemmeskoolu]

Call Tony at AAA Bus, LlC in PHX let him know Tee from NJ referred you, he has parts at reasonable prices and also a bus mechanic!! +16022789339

[musigenesis]

Originally Posted by lemmeskoolu

Call Tony at AAA Bus, LlC in PHX let him know Tee from NJ referred you, he has parts at reasonable prices and also a bus mechanic!! +16022789339

Thanks very much, I'll do that and see what he has.

[cadillackid]

doesnt look like changing the HPOP yourself is a bad job....

[musigenesis]

Originally Posted by cadillackid

doesnt look like changing the HPOP yourself is a bad job....

I've always been intending to get into the mechanical side of things on the bus, but right now pretty much everything is beyond me (I've never even changed the oil on my own car).

[CHEESE_WAGON]

Originally Posted by cadillackid

doesnt look like changing the HPOP yourself is a bad job....

Originally Posted by musigenesis

I've always been intending to get into the mechanical side of things on the bus, but right now pretty much everything is beyond me (I've never even changed the oil on my own car).

Guy in the parts department said he'd changed one, but there are some things that are a bit tedious (mentioned one bolt in particular that's a real b*tch to get to -- his words, not mine LOL)

[musigenesis]

Originally Posted by CHEESE_WAGON

Guy in the parts department said he'd changed one, but there are some things that are a bit tedious (mentioned one bolt in particular that's a real b*tch to get to -- his words, not mine LOL)

I had a hell of a time just getting a wrench on the hand primer.

[BamaBus]

Is there more info other than the 333 code on why the HPOP is being replaced?

[musigenesis]

Originally Posted by BamaBus

Is there more info other than the 333 code on why the HPOP is being replaced?

Well, I took it in originally because the engine was losing most of its power at high RPMs, at least sometimes. I think those symptoms plus the 333 code (which showed up twice) led the mechanic to conclude the problem is the HPOP. He also drove it around once the exhaust was done and confirmed the problem.

They've replaced the exhaust system from the engine all the way to the back, and replaced the front brake drums, and they're also going to be fixing my ABS (they have to find and repair a cut wire, which is going to be some unknown amount of labor), so the cost of the HPOP replacement seems less compared to the total bill.

It's my first time at this place, but they handle the bus work for most of the school systems in my area and are highly regarded, and they said I didn't need some other expensive things that I was planning on having done, so I don't really think they're doing anything unnecessary.

This will be a big hit, but I'm hoping it leaves me with a bus that will be solid and not requiring any massive work for a few years.

[BamaBus]

When searching this forum and other forums I have not come across any that the $2000+ HPOP is the first thing to replace. ICP sensor, IPR valve maybe. There should have been other test performed. I'm not saying that is not the problem, but just driving it and a single code would not be enough for me.

[johnbloem1974]

I would definitely change out the ICP sensor and IPR Valve before doing the HPOP.

I changed out the HPOP in my DT466E myself. It wasn't so bad, and I got the part for about $750 and sent back the old core.


John

[cadillackid]

For sure, hopefully they tested the HPOP proper and not just went by the computer.
It’s easy to see with a real gauge if the HPOP or sensor is at fault.

The ICP and IPR are quite common failures and a lot less pricey than the HPOP itself.

[BamaBus]

See page 430 in EGES-175-1 at THIS LINK. One of the possible causes listed is trapped air. I wonder if the air bubble issue got resolved (see page 52).

[musigenesis]

Originally Posted by BamaBus

When searching this forum and other forums I have not come across any that the $2000+ HPOP is the first thing to replace. ICP sensor, IPR valve maybe. There should have been other test performed. I'm not saying that is not the problem, but just driving it and a single code would not be enough for me.

I'm only speculating on what led to the diagnosis of a faulty HPOP, other than the power loss symptoms and the 333 codes. I will ask the mechanic why he did not consider (or how he excluded) the ICP sensor or the IPR valve as culprits.

[musigenesis]

I really am a maroon. The shop finished up with all the repairs a month ago, but since then I've had a steady small leaking of what I thought was oil coming off the bottom of the engine somewhere, so I took it back to the shop yesterday to see if they could find the problem. Turns out it was a fuel leak from ... the hand primer I changed myself in the course of trying to fix my power loss problem. A little bit of fuel was coming out of it when running, and taking some glop from the engine with it before it hit the driveway, making it seem like an oil leak.

The mechanic fixed it with a new copper seal (which I did put on with the pump although apparently not correctly) for no charge, at least.

[CHEESE_WAGON]

Awesome! Glad it's taken care of.