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cowlitzcoach
Advanced Member
USA
325 Posts |
 Posted - 09/17/2004 : 07:45:46 AM
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Hi all,
I have a 1989 Thomas Saf-T-Liner ER with a CAT 3208T that is giving me fits. For no apparent reason the engine will quit and not want to restart.
Four times in as many months it has just quit. Three times I removed the stop solenoid and was able to get the bus restarted. Two times required repriming the injection system. The fourth time the engine quit the stop solenoid was not installed.
Without the stop solenoid installed I can't think of any reason why the engine would stop running. Yes there is fuel in the tank. Currently there is at least thirty gallons in the tank. Since the bus is pre-electronic, even with the key off the bus should still be running if the stop solenoid is removed.
In each case, pumping the primer pump had fuel coming out of the bypass with just a couple of pumps.
Fuel filters have been changed.
The stop solenoid has been changed twice.
The air filters are clean and have no restriction.
When the bus is running it runs nice and smooth with lots of power.
Normally the engine starts right up, regardless of the weather. Most of the time the starter doesn't even make a full revolution and the engine will start. Now you don't even get a breath of smoke in the exhaust.
One time the bus quit the bus was going down a steep hill. One time the bus quit the bus was going up a steep hill. One time the bus was parked on the level and would not restart. And one time the bus was traveling on the flat and it quit.
Any suggestions are gladly received since I am clueless as to where to start looking for an answer. It has come to the point I don't want to send the bus out for fear of having to tow it back home.
Your help in this matter is greatly appreciated.
Mark O. |
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ModMech
Top Member
USA
948 Posts |
Posted - 09/17/2004 : 11:01:18 AM
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That sounds like a fuel supply problem, either a restriction or suction leak allowing air into the system until it loses prime.
We typically "T" a vacuum gauge into the secondry filter to check for any restrictions. If it reads under 5" at rated RPM then that should not be a factor. We also use a sight glass to check for air entering the fuel system before the transfer pump (on the suction side of the fuel delivery system). Very often we find porus hoses, lines or leaking fittings.
CAT is also known for the extensive use of braided fuel hoses. While I and not sure about what is installed on this unit, we very often find the hoses are collapsed internally. This happens most often on the pressure side of the transfer pump, but I've seen it on both sides. It's a "normal" replacement service on the bigger CAT engines suffering from poor power, stalling that have no other problems (air, restrictions). |
If you want customer service, you NEED an International! |
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BusBoy 1
Advanced Member
USA
212 Posts |
Posted - 09/17/2004 : 7:15:04 PM
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| Just a thought check your fuel tank vent tube to make sure its not plugged with dirt or something. This sounds the same way our 2000 freightliner cummins ISB eng would do in winter driving on snowy roads fuel tank in the rear of the bus the vent tube come down the side of the tank it would freeze over then the bus would just die let it sit for a while and sometimes it would start and run fine next time you had to bleed the system too get it to go but at that time we did not know what was wrong. took a couple headscrathing yrs too figure that out. Now we rerouted the vent tube and cut a 45 degree angle on the hose and we have went though a real cold and snowy winter and never missed a beat. so I would to see if yours is plugged with something that will not melt away when you try to find the problem. GOOD LUCK |
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Thomasbus24
Administrator
USA
4544 Posts |
Posted - 09/20/2004 : 2:37:28 PM
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Our 1987 Thomas pusher with the 3208 did this kind of thing, but only when it was cold outside...the pump just wasn't strong enough to suck the fuel to it, so we had to install an electic fuel pump in the line between the tank and engine.
Hope this helps! |
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CAT 3208T fuel problems
