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2coolr4skool
Active Member
USA
10 Posts |
Posted - 04/12/2018 : 11:06:00 AM
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i have an '02 ic bus with a T444 in it with 168,000 miles on it, occasionally it will go haywire and start running rough, coughing smoke and have little to no throttle response, it usually does this when it's trying to accelerate from a dead stop (student pick up) it is erratic and you never know when it will happen. I have replaced all the major components such as the IPR,ICP and even a new fuel pump. It gives no indication as to when it will do this and pocketmaxx says it is an " unknown occurence" . No DTC has ever shown up. the bus route is very close to the school and by the time a replacement is taken there the bus starts and runs and performs normally. just cant receive enough information to try and diagnose it. |
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JoeHEB1
Advanced Member
498 Posts |
Posted - 04/12/2018 : 11:41:18 AM
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Check the injector harness for burnt terminals. The injector harness connects at the top of the valve covers. Unplug it and inspect for burnt terminals, unplug both sides. You'll need to replace the connector, injector harness (under the valve cover), and the valve cover gasket if you find any burnt terminals. |
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slippert
Top Member
USA
630 Posts |
Posted - 04/12/2018 : 11:49:10 AM
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It you haven't replaced cam sensor...I would ck that. I remember having the inlines six do similar things and not throw a code sometimes,,, other times they would... had a couple of 444's here also and seems like I changed out a fair share of cam sensors on those too...with similar symtoms... |
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namao
Senior Member
Canada
89 Posts |
Posted - 04/12/2018 : 12:28:20 PM
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Just couple thoughts first we had 444 ic that had a stall at a specific spot on there run, lots of white smoke before it would stall, every time we would head out it would start and never act up on us. Ended up being the vent on the fuel tank was plugged, it would vacuum the tank till no fuel to engine and stall, leave it sit, it would bleed down and go again. The other issue was baffles breaking off in the older buses, the pickup sucking them up and loosing fuel. S basically if we would see a problem like this and no codes or direction to head we would get to the pick up, pull it , cut the bottom into a v so it could not be blocked. Then pull the vent, make sure it was not restricted. At least cover those bases right off. |
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2coolr4skool
Active Member
USA
10 Posts |
Posted - 04/12/2018 : 2:25:11 PM
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Have done it all to this engine, injector harness is good. cam sensors are a pain on these buses i know, have changed out a few myself. The fuel tank is going to get drained in the morning and that process will be scrutinized i can assure you. All great ideas, thanks for your expert opinions |
Calvin Taber |
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wrenchsnapper
Active Member
27 Posts |
Posted - 04/17/2018 : 1:46:21 PM
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No need to drain the tank. Just remove cover on the floor and the fuel level sensor and stick a telescoping magnet down and see if the baffle is laying down there . Either way just cut a couple of small notches in the end of the suction tube so it cannot be blocked off by the plate covering it when it slides around. |
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torque
Advanced Member
Canada
358 Posts |
Posted - 04/18/2018 : 05:15:52 AM
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Exhaust restriction? I had one in a E350 a baffle in the muffler had come loose. Put your foot into it and the baffle would plug the outlet. Shut it off would start up and be fine until the next time you foot into it or sometimes when you hit as good bump. |
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td083
Senior Member
195 Posts |
Posted - 04/27/2018 : 10:09:38 AM
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Have had one recently where the injectors were replaced almost a year earlier , and would exhibit intermittent running rough smoking no dtcs and hardly any throttle at times turns out a few of the injectors were not tightened correctly and worked loose , you could tell the bottom half of the injectors were black with carbon buildup all over . Just in case you get to that point where nothing is fixing the issue may be time to pull the injectors and check . |
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