All posts by Hex

bus trouble, Engine, learning, School Bus, school bus RV, Skoolie

Replacing the IPR *or* No more Hot Start Fail!

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So, I finally got to replace the IPR (Injector Pressure Regulator), in hopes of tackling the very frustrating Hot Start Fail problem that I’ve been dealing with on the bus’ T444E engine.  The IPR is attached to the base of the high pressure oil pump, between the valve covers and kind of under the fuel filter/water separator, and lots and lots of wires and air ducting.

In doing my research on changing this part, I found that I’d have to be prepared for some oil leakage from the high pressure pump’s reservoir, and that I’d need a deep socket to get the regulator itself out.  I had a chuck pad I could use (they’re really absorbent) and was able to slide it in under the old IPR to catch the escaping oil – though no quantity had been specified, just that I should “have a bunch of paper towels ready”.  I hoped I was ready.

The IPR is a solenoid valve, and the electromagnet comes off the stem that houses the moving bit to control oil flow.  So, to take the piece off, you first have to remove the holding nut, a spacer, and the electromagnet from the stem, which can then be unscrewed.
All in this very small place.

But it can be done, and relatively quickly, it turns out.  The electromagnet has an electrical connection for controlling it, and that just has two clips on either side, then slides out and can be woven back around some pipes and wires to keep it out of the way.  The upper portion of the plug is wider than the lower, so you can’t plug it in the wrong way – an important detail for putting everything back together and doing it by feel.

The next thing is to take off the 3/4″ nut that holds the electromagnet and spacer onto the stem.  This is a very thin metal nut, so it doesn’t take much to get it off, but if your 3/4″ wrench is long (like mine), be prepared to make a bunch of very tiny pulls to get it finger-loose.

Once the nut is off, the electromagnet and spacer should come right off.  I ended up having to unscrew the spacer for a bit along the threads for the holding nut before it broke loose enough to slide.  And a little wiggling was necessary to get the electromagnet to slide, but it came more easily than the spacer once I got it wiggling.

It was then time to get the deep socket.  In doing my research, I had taken the new IPR I had apart and fitted the stem to a large (shallow) socket that I had to find that it was a 1 1/8″ size.  Our local Autozone had a deep socket in stock for $8, so that wasn’t bad at all to get the right tool.  However, the stem is so long that you need every bit of space in the deep socket (I wasn’t sure that the ratchet end would sit in the socket securely), and it turned out that the deep socket’s center hole wasn’t a full 1/2″ in diameter, so it wouldn’t fit the stem up into it.  And of course, that would mean that the socket wouldn’t engage the points.  Luckily, I was able to use a 1/2″ drill and get the hole open so that it would work.

Then there was just the matter of getting the socket onto the stem, which involved some wiggling, moving of wire harnesses this way and that, and then, once on, doing some more of it it get the ratchet down to engage it.  For this, I ended up using the 3/8″ ratchet with a 1/2″ adapter on it to be able to get a better pull, as well as to get a spacer between the socket and ratchet that was long enough, but not too long, to work around hard engine elements.

The stem broke loose fairly easily, and with some wiggling and shifting, it came out!  I could see that the chuck pad had collected some oil, but couldn’t see how much at that point.  But the important step of removal was now complete.

I transferred the protective red plastic cap from the new stem to the old one, and set about reversing the process to install the new IPR.  The only real difference was that as I was tightening the new stem in place, I slid the chuck pad back away from the high pressure oil pump, so it wouldn’t have a chance of getting caught and messing up the seal.  Once the stem was nice and snug, and the electromagnet, spacer and holding nut were on and secure, I plugged the control wire back in.

In cleaning up, I checked out the chuck pad.  It looks like there might have been about 4-6 oz of oil that drained out when the stem came out of the pump.  I don’t know if that’s typical, but it’s my best estimate.

Once all the bits were stowed away, I started up the bus.  It cranked without starting at first, but knowing that it would have to pull enough oil to the high pressure pump before it would start, I kept it cranking, and then it caught.  It ran rather ragged for the first half-minute, then smoothed out pretty well.

The new IPR is more responsive than the old one, but some of that could be  in the fact that part of the seal on the bottom of the old IPR was missing!  I’m wondering if that, coupled with either less viscous hot oil, or perhaps some dynamic of the metal being heated was what was causing the hot start fail.

At any rate, a quick test-drive, then attempted restart of the engine proves that the engine now starts up fine when hot.  It also seems a bit more responsive to the accelerator pedal, so I have to get used to starting off in second all over again.

camping, driving, Monroe County Parks, school bus RV, Skoolie, trip, Webster Park

A Rochester Trip

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So, we had to go to Rochester, NY for the Science Exploration Day that St. John Fisher College hosted.  As we needed to be at the college campus at 9:00 for registration, as our son was going as part of a group of Rochester homeschool kids, and thus we could beat the crush of buses bringing in regular school kids.

We briefly looked at hotels to stay in overnight, as it’s an hour and a half drive from Buffalo, but even with the College discounts at local places, it was still pretty expensive.  Given that, I of course took a look for campgrounds.  And, only 20 minutes away from St. John Fisher College, I found Webster Park, which has some areas of shoreline on Lake Ontario.

The campground itself has 45 sites and is nestled back about half a mile from the shore, surrounded by light to heavy woods for all but the big motorhome sites.  All the sites have electric, and while only five have dedicated water, there are enough taps throughout that about the farthest you’d have to walk for water is two or three sites.  While the price per night was higher than we’d payed for any of the Erie County or State sites we’d been to, it was certainly worth it compared to the hotel costs (and proximity to Rochester and Lake Ontario probably causes a lot of demand for sites).

So, even with the bus still having the hot start fail, we decided that it would be a short enough trip that we wouldn’t need to stop the bus unless we were in a place where it could sit and cool before we needed to go again.  We would start in Buffalo and get to Webster Park, then stay overnight. Then we would go from Webster Park to St. John Fisher and shut the bus down for the classes.  Then, when we were ready, head out from the College and back home.

The trip to the park was fairly uneventful, though I did a horrible job of trying to stay out of the way of fast-paced cars on the Rochester expressways.  It seemed like as soon as I moved over into the right hand lane to travel at the speed limit, the lane was ending, becoming an exit-only, or the exit we needed was a left-lane exit.  And, for that I apologize to those inconvenienced drivers.

But some of the drive was wonderfully scenic, like on the Route 104 bridge, some 45 feet up over Irondequoit Bay.  We found the campgrounds with no problem, though the stretch of Lake Road from Bay Road to the park is a lovely twisty, hilly section that motorcyclists must adore.

Checking in at the park was simple – since I had printed out my email confirmation of our reservation, all they had to do was see that and we were set.  Monroe County’s reservation site was nice, as it give pictures of the sites as well as the electrical, vehicle/trailer length capabilities, and such.  From that, while site 19 and 21 looked big and easy to back the bus into, I ended up choosing site 15, as just down behind it was East Creek, and I thought there would be a nice view downhill behind the site.

Site 15 ended up being even nicer when we got there.  It was easy to get the bus backed in, due to the curve of the loop at that point, and contained the end of a little geographical ‘finger’ so that at the north end of our site we could look down toward a swampy area, much like we could look down into a low valley to our east.

 

Down at the bottom of the ‘finger’ was a path that we could follow back along to the west and north, which brought us to the Kanatota Lodge which overlooks Lake Ontario.  It was a great sunny day to be there, with splashing waves and a nice breeze.  And the hike only took us about 10-15 minutes.

Part of the reason for a longer hike than it might seem for the distance was that there had been a windstorm that brought down a number of good-sized pine trees, so we had to pick our way around or over those.  But, since we could use fallen wood as firewood, we didn’t have to use any of our own wood for the fire.

We had a nice meal of beans (pre-cooked from dry at home), peppers, and tomatoes all cooked up in cast iron over the fire and some home-baked sourdough bread, and were joined by a dear friend who came up from Rochester to spend the evening with us.  Marshmallows were toasted (or burned) over the fire on the telescoping prongs’ first use, and scary stories were told in the red glow of the embers of the fire, accompanied by bourbon for those (adults) so inclined.

We cleaned everything up just as a thunderstorm rolled in, and we all slept well.  The temperature had dropped, so it was a bit chilly, and the sky was a little overcast after the storm, but the bathroom facilities were a warm, and we were able to set out on-time to brave the morning commuters along our route to the College.

I gave us an extra 20 minutes on top of what Google had suggested as travel time for us, and that all worked out – though again, I ended up facing the need to merge into a left-hand exit with rushing commuters doing the same.  My thanks to that pick-up who took pity on us and gave us space to merge!

The Science Exploration Day was a whirlwind of presentations.  The 40 minute presentations were followed by 10 minutes of trying to find the next one’s room.  Construction in one of the buildings, and different numbering directions in differing buildings made this a challenge, but our son got into some cool ones, and as I hung around outside the oft-packed classrooms, I overheard some good presentations.

We had parked in the back of one of the parking lots, and returned after the last presentation to our bus being surrounded by a myriad of national school bus chrome buses!  We stayed and ate some lunch while buses pulled out to pick up school kids, or loaded in the parking lots.  We got some looks, and had some homeschoolers come and take a look at our set-up.

One of the things we found was that the batteries for the linear actuator keychain remotes were dying or dead, meaning we only had one working.  But the batteries were easy to find, and replacing them was the job of a screwdriver and taking the keyring off, taking only a minute to do.  

After all the buses were gone, we packed up our lunch and headed out.  Our trip was a bit slower than our trip out to Rochester, as we got stuck behind … school buses dropping off students!  But we all had a great trip, and would be happy to go back to the Webster Park Campground.

 

 

Post Script: As far as the bus engine, it ran flawlessly, even for long periods.  And on our trip out, the ambient temperature was in the high seventies, and the running engine temperatures on the highway were approaching 200, and it didn’t falter.  I did try starting it hot at the campground after we parked, and it still hot failed. More on this later.

bus trouble, Engine, learning, school bus RV, Skoolie

Hot Start Fail

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So, we had a nice day, and I decided to take the bus out for a test-drive.  Well, a test-start, really.  I figured that I should try and document what was going on, as I had read the last  service paperwork (where they couldn’t replicate the problem after it got towed) more closely while cleaning up on the bus.  The way it reads, they were looking for a hard start, but proved that the bus would repeatedly start when it was cold, and wouldn’t quit once running, which wasn’t the problem.

So, I videoed the cold start before a quick trip, and the attempt to start it hot that failed.  (Caution, it’s a bit jumpy at parts, as I had a webcam that I was holding in my hand to take pictures at times.)

This really shows the difference, and how the engine started/didn’t and how it sounded, mostly for my own reference, and to possibly take into the dealership to show them.

But in putting it together and watching it after I had uploaded it, I noticed how low the oil pressure was (I had been looking at the temperature, not the oil pressure).  While I had asked the mechanics at the dealership if the pressure was too low before, and they assured me that it was fine, this looks really low.  And since one of the things about that sort of non-start is the IPR (Injector Pressure Regulator) failing, so the injectors don’t get enough oil to function, that could be it.

Unfortunately, there’s also a possibility that it’s the whole High Pressure Oil Pump, which isn’t thrilling.  So, the next thing is to replace the IPR, and see what that does.