gutless

[gbstewart]

fresh oil will also help the injectors work properly ,you may also want to run some good injector cleaner as well, if the bus has been sitting
gbstewart

[gbstewart]

as a side note, always carry fuel filters with you, its the first thing to try if you run into any problems.
gbstewart

[cadillackid]

also make sure its exactly the correct fuel filter for your engine.. fuel filters come in different degrees of filtration... (microns)... make sure they give you the recommended by manufacturer filter... too small micron and the filter will fail to pas enough fuel after it has been in a short time... too large and it doesnt filter enough cntaminents out..

also watch your temperature and be sure your engine fan fully engages.. you dont want to get that T444 hot!..

I would also only run the new oil for a short time then change it again.. as already mentioned your fuel injection system is tied to having clean oil and good pressure... at the very least if you dont want to fork the expense of an oil change again real soon.. then change the filter after a short time..
-Christopher

[pegabus]

I also have a T444E with a Alison 545. and yep its a gutless pig from a stand still. several times if I park in a gravel or dirt lot the vehicle sinks in about 6 inches. When I try to pull away out of the ruts, it will not move. Not enough power, stall, torque what ever. I have to usually rock the bus back then gun it quickly to go forward. Build up a little momentum and she will go. no momentum it just stalls on the torque converter, and builds a lot of heat.

I researched AT643 replacements and here are the problems. if you dont have a core to return when you purchase a rebuilt one, add 1,000 core deposit. the case is a lot longer due to the extra gear so driveshaft length will have to be cut and that can be costly. the bell housing adapter plate will have to be changed, different starter, little wiring modifications but nothing to big. so It all priced out about 5,000-6,000 cost to do all this. The AT5454 as much of a crap trans it is I can replace it twice for the cost of an 643. hope this info helps

[Tango]

You can buy a new from the factory Allison 2000 series 6 speed, built to your specs for a little over $7K. And the new gens can talk to an all mechanical engine with nothing more than a TPS.

[EastCoastCB]

Originally Posted by pegabus

I also have a T444E with a Alison 545. and yep its a gutless pig from a stand still. several times if I park in a gravel or dirt lot the vehicle sinks in about 6 inches. When I try to pull away out of the ruts, it will not move. Not enough power, stall, torque what ever. I have to usually rock the bus back then gun it quickly to go forward. Build up a little momentum and she will go. no momentum it just stalls on the torque converter, and builds a lot of heat.

I researched AT643 replacements and here are the problems. if you dont have a core to return when you purchase a rebuilt one, add 1,000 core deposit. the case is a lot longer due to the extra gear so driveshaft length will have to be cut and that can be costly. the bell housing adapter plate will have to be changed, different starter, little wiring modifications but nothing to big. so It all priced out about 5,000-6,000 cost to do all this. The AT5454 as much of a crap trans it is I can replace it twice for the cost of an 643. hope this info helps

I've seen nice used 643's for around 700 bucks.

[Kubla]

Paid $650 for my MT 643, still have not done anything with it, discovered after I bought it that they came with 3 different torque converters, nor sure which one I have, difference is the torque multiplication ratio in the converter, higher multiplication, better low speed pulling ability

[Bungeekord]

ok, thanks pegabus for the solidarity on sluggishness, and everyone else for chiming in. Im pretty convinced the trans is ok.

Just got some Transynd for the trans, going to change its fluids and filters tomorrow as well as try to drain the old diesel out of the tank and refill with fresh fuel, and replace coolant as well.

I did get temp tags and had it out on the road for a test drive the other day and it still seems sluggish. Vac/pressure gauge is still showing a significant strain on the fuel system. Where as I remember it normally running between 5 and 10 psi of pressure (it oscillates because of the electric fuel pump i assume?) under load, its now showing a much wider swing... I pulled out the tiny inline screen filter between the primary fuel filter and the electric pump, and to my disappointment it was clean (I was hoping for an easy fix here). I will try disconnecting that primary fuel filters inlet line and blow back to the tank, perhaps the pickup is clogged?

For the fuel filters I used napa 3217 for the water separator and WIX 33817 for the spin on type with the built in cap. Both are rated at 14 micron, when I replaced them the water separator seemed pretty dirty but the second one was clean.

Hoping its just a dirty pickup. will keep yall posted!

[Bungeekord]

Well, did a bunch more on the bus and it still seems to be sluggish. Drained fuel tank and blew back to tank, fuel looked very clean but replaced with new.

Im wondering if it may be some of the electrical injection controls or what else could be making it seem to strain so hard. The fuel pressure/ vacuum guage is still showing a lot of strain. Would the injectors effect this? My experience is tha its usually a clogged fuel filter that causes strain on the fuel system, but with all new correct filters, it makes me wonder what else could contribute to this?

Where its flat ground it seems to eventually get up to speed and hold it, but on hills its a real turd.

Im running out of time as were hoping to move in a week. Hoping for some helpfull suggestions.

[Tango]

Just based on what I have read here so far...it still sounds like the tranny to me. ("engine revs but it doesn't go").

[turf]

no improvement with the Transynd is disappointing to hear. hope you get it figured out.

[cadillackid]

everyone's idea of "sluggish" is different... if the bus is on flat ground you pound it to the floor how long does it take to reach 30 MPH, 40 MPH, 50 MPH, and 60 MPH.. pretty much every bus ive driven is a LOT slower than a car..

yes the newer one with higher horsepower engines and lockup transmissions will do much better but it may just be normal for your bus.. there are a lot of slow busses on this forum...

mine will go 68 Maxxed if I run it foot to the floor on flat ground but when I run it 60, its practically a dream to drive.. so i just dont run it faster unless I feel im a danger in the downtown traffic of a city or such then Ill push 65...

if tyou time your speed-up and its way sklower than other busses liek it then id be concerned of an actual problem but if it seems to match other similar busses and drivetrains then id pack the sucker full and have a nice relaxed moving trip

-Christopher

[Jolly Roger]

I have an 86 with an 8.2 and the 545 and with the peddle to the metal I am slow off the line, hit 2nd about 15mph 3rd about 23 and drive about 27-30 after that it takes a few to hit my top end of 49mph.
My rear gear of 6.50 needs to be changed along with taller drive tire to hit 60.
My bus stays in a gravel/dirt drive and no more than I move it right now? Because of the sinking, I am at at least 3/4 throttle to start moving but after that it is bottom out on the main road to anywhere.
Check your rear gears for size.
Mine are designed for stop and go with some pulling power and that's why I am slow with 6.50 gears.
From what I have found? For highway speed I need to be in the 4 range but I will lose a lot of the towing capabilities? So I am still debating what change I want to make.

[Bungeekord]

yes i get it that sluggish is relative. What I am comparing it too is my previous driving experiences, where it certainly wasn't a race car, but also had a bit more pep in its step.

I was able to get up to 45 (speed limit) along a flat stretch in probably 35-40 seconds? didn't time it...

my main concern is hills. A few times today driving around town, climbing hills from a dead stop the bus struggled to push 15 mph. Or would loose speed significantly on hills of decent grade and distance. Not altogether uncommon for an older diesel for sure.

the other frame of reference I am using is the gauge on the fuel system which seems to be showing a much wider range of swing then when it was first installed and the bus was running like a top. I am considering the fact that with the veggie oil plumbing and pressure /vac gauge plumbing there could be a small air leak somewhere causing the gauge to swing like it does. I will try to inspect and tighten all threaded connections tomorrow as well.

I didn't hit the highway today, it was in the 90's here in Western North Carolina, but chugging around this hilly town I did see some temp climbs into the low 210's. I'm hoping that will be the top temps I see, but the true test is some of these mountain passes leaving out of NC and TN. I think once I hit 81 in VA I will be good.

Planning to get out on the highway and hit some hills with some speed behind me. Will try to time my acceleration speeds while im at it. Will keep y'all updated.

[retiredChemist]

Originally Posted by Bungeekord

yes i get it that sluggish is relative. What I am comparing it too is my previous driving experiences, where it certainly wasn't a race car, but also had a bit more pep in its step.

I was able to get up to 45 (speed limit) along a flat stretch in probably 35-40 seconds? didn't time it...

my main concern is hills. A few times today driving around town, climbing hills from a dead stop the bus struggled to push 15 mph. Or would loose speed significantly on hills of decent grade and distance. Not altogether uncommon for an older diesel for sure.

the other frame of reference I am using is the gauge on the fuel system which seems to be showing a much wider range of swing then when it was first installed and the bus was running like a top. I am considering the fact that with the veggie oil plumbing and pressure /vac gauge plumbing there could be a small air leak somewhere causing the gauge to swing like it does. I will try to inspect and tighten all threaded connections tomorrow as well.

I didn't hit the highway today, it was in the 90's here in Western North Carolina, but chugging around this hilly town I did see some temp climbs into the low 210's. I'm hoping that will be the top temps I see, but the true test is some of these mountain passes leaving out of NC and TN. I think once I hit 81 in VA I will be good.

Planning to get out on the highway and hit some hills with some speed behind me. Will try to time my acceleration speeds while im at it. Will keep y'all updated.

Probably a leak, if not,
Is the veggie oil strained to same or smaller than the filter?
What's your cfpp on the oil?
What's your TAN on it?

I have seen the problem where TAN is off and it eats the pump internally.
Cfpp is usually a freezing cold weather problem, unless you're using a palm oil blend.

[Bungeekord]

sorry, i know this is confusing.

the veggie oil system is plumbed separately and I am not currently burning veggie oil. Using diesel at the time being, which is entirely independent from the VO

[retiredChemist]

Does your cold start system have a magnet on the end of the injector pump to pull the rack open?

If so try hitting the cold start when it loses power.

[Bungeekord]

pulled out the veggie oil solenoid and the fuel pressure gauge sender set up, and got on the highway. And it totally kicked butt! It felt more or less the same at take off but once I got it up to 45 it felt strong and totally climbed to and held at 55 - 60. Even climbing some big hills it held at about 45-50. So, Im happy with it.

I disassembled the pressure/vac sender T and cleaned up all the threads on the hose barbs/components, and reinstalled them using high temp thread sealant. Will plumb it back in tomorrow once it all dries. Its a useful diagnostic tool even without the veggie system running.

I did notice a very small amount of coolant beneath the bus after it had been parked for about 20 min and think its the thermostat gasket as it looked wet around the housing. Left it running when I got it back home and didn't notice it actively dripping or leaking, so it might just be a minor issue.

What temp thermostats are best for this engine? I think i don't have one in mine. remember pulling it for some reason a while back and its sitting in the cup holder on the dash. It might have stopped opening... Oriellys couldn't source one.

[jazty]

This is great news! And I agree with you: it's worth keeping that fuel pressure gauge if you can get it running without restricting the fuel flow.

Originally Posted by Bungeekord

I did notice a very small amount of coolant beneath the bus after it had been parked for about 20 min and think its the thermostat gasket as it looked wet around the housing.

While it probably is the thermostat gasket, those thermostat housings are notorious for leaking. If you find that it is the housing then you can upgrade to a billet style housing: 7.3l thermostat housing | eBay

Also, the fan clutches do crap out, too. Mine hasn't come on yet in my T444e. I've had to use the interior heaters a handful of times to dump heat out of the engine.. Mighty uncomfortable in the summer heat! A new fan clutch is on the todo list.

[Bungeekord]

that thing looks just like my housing. not sure what the stock set up looks like...

is a thermostat from a powerstroke ok to use? whats the ideal temp thermostat? any danger in not running one?