mcratchet1 Posted Tuesday at 05:20 PM Share Posted Tuesday at 05:20 PM Hello, I have a strange issue with my 2013 Mack mru with mp7 engine. I was pumping in the rain and truck try to kill four different times. Rained stop no problems came back to shop. Getting a pid94 fmi 7 code. Pulled truck up and degreased around fuel filter area. Try to start truck it crank and ran about 1 minute and stalled. Would not start up. I took my blower and dried the whole drivers side engine and then it started right up. So is there a sensor issue or wiring intruding water that would stop truck from starting. Just trying to get an idea where to start looking. Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/75731-rain-shut-truck-off/ Share on other sites More sharing options...
JoeH Posted Wednesday at 07:10 PM Share Posted Wednesday at 07:10 PM Try spraying wd40 on things next time it happens. Our old 1960s forklift the distributor cap and spark plug wires don't like rain, but it'll run if you spray some wd40 on it. Quote Link to comment https://www.bigmacktrucks.com/topic/75731-rain-shut-truck-off/#findComment-578389 Share on other sites More sharing options...
mcratchet1 Posted 18 hours ago Author Share Posted 18 hours ago Ok, I checked all the banjo bolts on fuel lines and found the ones on fuel pump loose. Idk if that has anything to do with it. If loose seems like they could suck air unless water changes this issue. But that’s above my paygrade. I’m new to these electronic emission trucks. Thanks! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75731-rain-shut-truck-off/#findComment-578423 Share on other sites More sharing options...
Geoff Weeks Posted 14 hours ago Share Posted 14 hours ago SWAG, but I would look for a wire that rubbed through and make enough of a connection when wet to fowl things up, dry the resistance goes up and it works. Guy I knew with a KW had an intermittent problem, turned out a one point someone got some wires caught in the oil filter when it was tightened down. Must have pinched off some insulation and then when they were removed from the oil filter, would occasionally make contact with the block and the truck would die. Took many shops many tries to find that one! 2 Quote Link to comment https://www.bigmacktrucks.com/topic/75731-rain-shut-truck-off/#findComment-578433 Share on other sites More sharing options...
Brocky Posted 8 hours ago Share Posted 8 hours ago I think GW is right??? A pinched or rubbed thru wire somewhere far enough from the block that engine heat will NOT keep it dry and the moisture is letting it short out???? Since your blow dry cured it, somewhere on or near the firewall????? Quote Brocky Link to comment https://www.bigmacktrucks.com/topic/75731-rain-shut-truck-off/#findComment-578456 Share on other sites More sharing options...
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