Sean MACKeever Posted January 8, 2017 Share Posted January 8, 2017 Hi guys and girls around the world. I have recently come across an issue with my 1993 MH Ultraliner, it starts up fine but shuts off after around 20 seconds or so. Has anyone had anything like his happen to them or have you heard of it. Its a 1993 E7-400, there is a small air cylinder and a solenoid on the fuel pump which shuts the engine down, I cant find whats causing this to operate and shut her off. Cheers Sean Quote Link to comment https://www.bigmacktrucks.com/topic/48275-truck-shuts-down-after-20-seconds/ Share on other sites More sharing options...
41chevy Posted January 8, 2017 Share Posted January 8, 2017 (edited) I may be off base, but I would say that it was not seeing a oil pressure signal. the kysor system uses module that controls the shut down and reset gives it self maybe 10 seconds or more to see oil pressure then it shuts down and is reset by the start mode. But you will have to get a manual to check it with. There is different ones. One system you have to hold a switch down or in till the oil pressure builds then it is in reset and the other resets from the starter switch. Google for the manual and I think you will find one you have. Edited January 8, 2017 by 41chevy 1 Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment https://www.bigmacktrucks.com/topic/48275-truck-shuts-down-after-20-seconds/#findComment-357543 Share on other sites More sharing options...
theakerstwo Posted January 8, 2017 Share Posted January 8, 2017 You can only guess till you read the codes. 1 Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/48275-truck-shuts-down-after-20-seconds/#findComment-357550 Share on other sites More sharing options...
Popular Post BC Mack Posted January 8, 2017 Popular Post Share Posted January 8, 2017 you possibly have a "Kysor engine protection system" in your MH.... the control relay is in the dash, your passenger side, near the relays and c/breakers... sort of an oblong shape about 4x3" with "Kysor" stamped on it... it monitors engine oil pressure and coolant level and gives a warning alarm if out of spec, in your case it also activates a shutdown solenoid... I have it in an E9 but no auto shutdown. check coolant level and watch oil pressure on start-up, it will wait a short while for oil pressure to build before it takes action. do you hear the alarm before it shuts down? and can you see an "over-ride" switch on the dash? if this really is your problem, and I'm guessing a lot here, then check coolant level and oil pressure, after that you may need to diagnose the system... to do that you will need the "Mack MH electrical system" manual, got one?... if not, I may be able to scan a page and post.... but check the above and all electrical connections.. sounds like the protection system is doing its job..!!! get back to us BC Mack 3 Quote Link to comment https://www.bigmacktrucks.com/topic/48275-truck-shuts-down-after-20-seconds/#findComment-357553 Share on other sites More sharing options...
Sean MACKeever Posted January 8, 2017 Author Share Posted January 8, 2017 Thanks very much for the responses guys, I have to wait until tomorrow evening before I try again as the air start tank is empty and I don't want to start letting Tyres down to start her if she doesn't run long enough to inflate then again. I havent a wiring diagram or manual for my specific truck but was reading up on other models. I have done some investigation work tracking the wires that operates the shutdown solenoid, this goes through to a pole on the ignition. Reading the manuals I have tracked a Kysor shutdown system to a pole on the ignition. I had never heard of this system before or where to locate it, so thanks "BC Mack" for the location. 👍👍 I'll double check all fluid levels and watch the gauges on start up. Cheers Sean Quote Link to comment https://www.bigmacktrucks.com/topic/48275-truck-shuts-down-after-20-seconds/#findComment-357556 Share on other sites More sharing options...
BC Mack Posted January 9, 2017 Share Posted January 9, 2017 I may be getting ahead of the problem here.... and I'm taking a guess that Aus built MH's share similar electrical systems to US built trucks... I have attached two references from the MH electrical manual which may be of use if this is the problem. if you are sure of the coolant level and need to see the oil pressure rise, you could take a risk and disconnect the wiring or linkage from the solenoid, that will allow the engine to run (idle) while you build air and watch the oil pressure, just be ready to shut it off.... BC Mack 1 Quote Link to comment https://www.bigmacktrucks.com/topic/48275-truck-shuts-down-after-20-seconds/#findComment-357668 Share on other sites More sharing options...
Sean MACKeever Posted January 10, 2017 Author Share Posted January 10, 2017 Thanks very much for flicking those through, that's awesome. Ive been a little tied up with work but managed to meet my mate over the yard after he finished work and got the air starter tank filled up. I've checked the coolant water and fluid levels and are all good so tomorrow after work I'll disconnect the shutdown linkage, start her up and watch the oil pressure gauge, if it doesn't build I'll shut her off, if it builds fine then I would say the sensors faulty. Quote Link to comment https://www.bigmacktrucks.com/topic/48275-truck-shuts-down-after-20-seconds/#findComment-357815 Share on other sites More sharing options...
Sean MACKeever Posted January 13, 2017 Author Share Posted January 13, 2017 BC Mack I would say your pretty much on the money mate. I found the Kysor system you were talking about and located the oil pressure sensor. I disconneted both the oil pressure and the water level switch and started her up, she ran for close to a minute and then shut down. I played with the wires on the water level and the buzzer altered pitch slightly. At one point the shutdown light on the dash turned off and I was hopeful but then it shut down again. Now I have most of he dash apart and the sensors located I might get a sparky to come and give me a hand. Quote Link to comment https://www.bigmacktrucks.com/topic/48275-truck-shuts-down-after-20-seconds/#findComment-358241 Share on other sites More sharing options...
Sean MACKeever Posted January 21, 2017 Author Share Posted January 21, 2017 Finally got to the bottom of the shutdown issue, after taking the interior apart and tracking the wiring, locating the Kysor system and sensors it comes down to a faulty acuator solenoid. Looking back I should have taken this off and tested it first however it's been a good process, getting to know the truck in more detail and where some parts are. Below is the faulty part, I have a new one coming from USA be a good week + before I see it here in NZ. Thanks for all the help guys,. It's been greatly appreciated. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/48275-truck-shuts-down-after-20-seconds/#findComment-359217 Share on other sites More sharing options...
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