Throttle control T444e/545

[Paperman]

I have a 1999 3800 Blue Bird. t444e/545 190,000 miles Picked it up in MS for the rust free body. Speed sensor was missing in the 545 so that was replaced as well as the ICP sensor.

My question is now when I pull it into gear the throttle pedal has no control over engine power until it stats to accelerate. I can rev it in neutral as I would expect but in my soft yard it has a hard time moving as there is little to no power to roll out of its divots from sitting in the grass. Once she is rolling it pulls good but I fear stopping on any type of hill and Im dead in the water. Any input from the brain trust? Thanks RK from Northern MI.

[Tango]

Could the tranny be slipping?

[Geo Jeff]

How's it go down the road. do you have tach to read. In the grass or soft stuff you really do have to lean on the throttle quite a bit to get them rolling. Think of soft dirt grass like flat tire. If you have a issue its probably more likely just the convertor. being its not a lock trans I kind a get the feeling since your not having a issue any where else that is what your feeling is old bent turbine wheel. Or a old engine with low compression. A old dead engine goes down the free way but its not quick any more. Id buy a gauge and check the pressure on the transmission. Also I would pull the filter and clean it and reinstall it. It may just be limiting volume. god knows you can have good pressure on a gauge and still not have enough volume to shove this much weight down the road. Its hard diagnostic with out a test drive. I feel a transmission shop may drive it and just know from that. Good luck like I said it may just be fine. I wouldn't judge to much in the grass get it in a parking lot and see how much better its and maybe a video. Does it hit its shift points at the right rpm or does it hang out there for a bit?

[2kool4skool]

My 545 has failed to move me out of a hole once. It was in the 30s and not warmed up. I rocked it and it pulled right out. When warm it's got good pull, I parked there again once and this time it spun the drive wheel. We have a nearby hill that's about 11% and I can pull that from a stop, even towing.

[Paperman]

it acts as if the throttle is dead, not even there. I drop it into gear and try to power brake it on my paved driveway, nobody home. I can pump I
Up and down on the pedal and the engine does nothing in response. In neutral it campe rev and will change RPM with the slightest bump. I'll like to another thread in a different forum that also describes the issue.

[Paperman]

Link to schoolbusfleet that has the same issue. Tried to sign in and log in to talk with the poster but am having issues.


"http://www.schoolbusfleet.com/forum/topic.asp?TOPIC_ID=24193"

[2kool4skool]

If I use CC for high idle there will be no foot throttle response in gear until I disengage the CC.

[Paperman]

No cc use. As soon as it starts to move it acts normal. Almost as if it need to see some speed before it allows the throttle to be active. I'll make a quick video later today if I can.

[Brian Jacobson Glass]

Hey, I realize this is an old thread but did you ever figure out your problem? I’m experiencing the same thing

[cadillackid]

the 444E uses an electric modulator thats on the left side of the trans. the computer puts 12 volts to the solenoid which puts the trans into "kickdown" mode.


make sure the TRANS fuse isnt blown in the dashboard fuse panel first before anything.. these Modulators are a known failure point. I had one die on one of my busses and over time it ended up being the demise of the transmission..



applying 12 vlts to the modulator on the bench (when you clean it up you can see its marked + and -.. the solenoid shoud make a "Clack" and the pin move..



if the modulator is good, the next step is the TRANS relay on the firewall under the hood.. there is a bank of 3 or 4 relays and the Trans will be marked..

[Brian Jacobson Glass]

Thanks for replying. I guess I could have supplied a little more info. I didn’t want to high jack an old thread and was just curious if Paperman got it sorted out. But while you here lol….
I have a 2000 t444e runs great minutes a hard idle when you have the foot on brake in gear with engine hot. (Like idling at a stop light) Also hesitation on acceleration.

Also when idling at stop light with hard idle with my foot on the brake, if I press the gas nothing happens. If I take my foot off the brake it’s start rolling and slowly kicks in.

If it’s idling normal (like when the engine is not up to temp) I can have my foot on the brake and it idles normal and the gas pedal is responsive. Only seems to happen when up to temp but pretty consistent. Hoping it’s not a torque converter issue. I’ve done the Cps, Ipr, Icp, I’ll change, and even threw some archoil in there for possible Stiction. Injectors tested good.
Today I was thinking thinking it may be the Throttle position sensor. I did the ohm test on my pedal but confused myself with readings lol. I order a cheap tps well see if that changes anything.

Btw I’ve read many many of your posts Cadillackid. Thanks for helping so many so thoroughly. If you got time and feel like supply any insight I’m all ears. In any event cheers

[Brian Jacobson Glass]

also I will check those things you mentioned about the tans and get back as well. Thanks for your time