Heavy Equipment Forums Heavy Equipment Community

Working on any equipment with an ecm

Bumpsteer · 2018-12-22 20:39

How complacent one gets, chasing down a code rather than look for simple shrit first..... I know better, it just doesn't come to the front of the brain sometimes. Working on my Polaris Ranger, had a injector fault that could've been 3 different things. Checked everything electronic I could, nothing. Decided to inspect the wiring to various sensors, it can be an issue, nothing again. Looking down I spot a 1 1/4" crack in the throttle body to head boot... Stupid me, It finally sunk in that almost every damn problem I've had with this thing is caused by engine vibration. Just hope I remember it next time. Ed

Replies19
  1. #1Old Doug2018-12-22 21:46

    What is it that makes a guy think the worst and look past the easy stuff.

  2. #2Birken Vogt2018-12-22 22:14

    Happens to me all the time. You have to look all sorts of strange places to find the problem some times. I made a post recently about an RV generator where the fuel line was pinched in a non-visible place. Caused all kinds of people all kinds of hassle before I found it by good luck.

  3. #3WCR732018-12-22 23:25

    Just do what the “good” mechanics do, make it sound good. If you woulda told us “I had a bad ECM and a torn boot” we never would have know the difference. At least guys like us can admit when we **** up. That’s what really matters. Guy at work couple weeks ago, working on a 6.7 Ford with a squealing noise under load. Said “it’s got a bad turbo”... I asked if he’d checked for exhaust leak at manifold, he said, with confidence, “no, I know it’s the turbo”. 3 days later (yea, 3 days) after turbo R&R, the test drive proved him wrong, still squealing under load. Turned to me and said, “oh it had 2 problems, bad turbo and broken manifold bolts” I laughed, and said “sureeee”

  4. #4Birken Vogt2018-12-23 00:18

    Told to me by another mechanic "You mean all those parts went bad and caused that one problem???"

  5. #5DMiller2018-12-25 11:41

    Tried to impress the Newbies I would have to break in to NOT Ignore the Simple crap as broken bolts sucked out or popped gaskets, something getting loose but always had that same level of conversations with them once they found the Actual problems. 'Yeah needed a Throttle Body rebuild and that intake gasket just happened to show up popped, must've happened when was backfiring' (like never), or a Cummins needing injectors 28000 miles after an overhaul, asked if ran an overhead first always came back as did that when swapped injectors. Too easy to skip OBVIOUS issues. 4WD would not engage on a late model utility company five ton truck, mechanic I worked with said flatly needed the transfer case rebuilt, just knew it. He went on a service call, I found the cracked air shift control line unioned it and sent the operators off to work, he came back and whined I stole his gravy job. He never shut the engine off or watched the air pressure bleed off when 'Diagnosing'.

  6. #6Muffler Bearing2018-12-27 17:44

    I once knew a mechanic who had never been wrong..EVER. I watched him troubleshoot a boost code on a 60 Series. He replaced the turbo and that didn't fix it. Parts had given him a bad turbo off the shelf, so he got another, THAT ONE was bad too! After yelling at the parts dept for giving him junk parts he put on a third turbo, and a boost pressure sensor. The code cleared can you believe the luck? two bad turbos! After watching that I thought, that is no way to live.

  7. #7BigWrench552018-12-27 18:14

    One day my boss called and said, go to cat and pick up the new hydraulic pump and put it on. This machine is a 972g and you have to pull the cab to access the pump. So I picked the pump up and called the mechanic that troubleshot the pump. I asked him why he thought the pump needed to be replaced. ( because at the time it was a low hour machine with no other known problems) He had told me that the low hydraulic pressure alarm was going off and the laptop said when that happens the pump needed to be replaced. I then asked him if he tested the sensor that tripped the alarm. He then got a little pissy and said that there was no need to because the laptop said the pump was bad. Long story short I tested the pressure sensor and then installed a gauge to verify that I was correct to find that indeed the sensor was bad. Left the job site went back to cat and returned a $2500 dollar pump and picked up a $90 sensor.

  8. #8John C.2018-12-27 18:42

    Nice that you were honest. I've known some people who would have changed the sensor and charged for the pump and then sold the pump on their own.

  9. #9BigWrench552018-12-27 18:52

    I never thought of it that way. I was just thinking man this is going to be a lot of work and I really don’t want to do this. So out of pure laziness I checked to be sure if I really needed to do the work. I tell people all the time that being lazy made me a good mechanic. I learned to troubleshoot well because I don’t want to do work that wouldn’t fix the problem.

  10. #10MarshallPowerGen2018-12-28 13:40

    Had a propane RV Onan at the shop when I dropped in to stock the truck. No start and was told it needed the demand regulator and FSS replaced by the boss. Had been sitting there a few days waiting for parts. Went and checked it over first, pulled the regulator vent line and found it clogged. Shot a solid clump of dirt out of it with shop air, reinstalled and started right up. I wasn't around to see how that was explained to the customer.

  11. #11DMiller2018-12-28 15:47

    Just dealt with another one. Local was working some bad marker lights on a trailer, had the three light bar but nothing else and could not find a hot wire anywhere. I happened to walk in as he was getting ready to run 'A New Wire' to feed the lights, asked if had checked plug power, got Mansplained how all the truck lights work, asked again, 'Did you check the plug first?' He got mad jerked the plug from the truck, stuck a testlight in the truck socket and had two marker/tail powers, I then asked the obvious, what about the trailer side? In a huff he opened the trailer plug and all this green stuff came cascading out. Needless to say, a new seven way RV flat terminal plug and all was good again in the world.

  12. #12tool_king2018-12-28 19:23

    There are some real winners out there for sure .That is why we have to make them do stuff the right way.

  13. #13Raildudes dad2018-12-28 19:38

    I was a young guy many years ago. I'm a civil engineer. I can do basic service type stuff, lights, fluid changes, but I didn't and still can't tear an engine down. I make a great helper since I can usually anticipate what's needed next and know my way around a tool box lol. So I take my new bride's car in for a tapping sound. The service writer tells me it sounds like valves to me and writes it up for a valve job. Calls me the next day or so and says your car is ready. I go with checkbook in hand to pay for a $250 valve job (I know a long time ago lol) and the bill is $60. I question him and he says, "we opened it up an found a worn lifter. I had the mechanic just flip it over. I'd do the same with my own car." I went home and told myself, I going to take my car where ever this guy goes in the future. He could have reversed the lifter and charged me for the valve job. No way I would have ever known. And I did follow him until he retired as the service director for a large local dealership.

  14. #14Birken Vogt2018-12-28 19:48

    It is easy, just use a ratchet set for CCW, and sometimes a pry bar and/or a hammer. You will have a pile of parts in no time at all. It is putting them back together that is more troublesome.

  15. #15DMiller2018-12-29 08:36

    Pretty funny BV!!

  16. #16DMiller2018-12-29 08:45

    There are also those Dangerous people with 'tools'. Had a tow in YEARS ago, a first gen Ford 7.3 Electronic Fuel Control just over a year old. Was told just Died and would not restart, had less than 20,000 miles so asked why not at Ford. Pickup Owner said could not get to it fast enough and needed it back badly. Did a few basic diagnostics, ECM was dead FLAT dead, was unplugging it when noticed the 'Pin' holes in wiring at the ECM. Asked the owner when it died was there anything he had done? He got defensive, muttered something about buddy of his came up with some kind of magic found it from another buddy just pin two wires together will make Tons of HP crap. Went thru EVERY wire on the truck, found Two more similar 'Fixes' resealed the wiring, replaced the Shorted Sensors and ECM, close to $2000 in bill and guy starts to flip flop. Told him can pay and go or not pay and the truck sits, he paid, check bounced, tried to claim WE had damaged the wiring and tried to sue, my boss had all the evidence written down and the suit disappeared but the bill never paid.

  17. #17Raildudes dad2018-12-29 10:18

    I said that all wrong . Yes I can tear one down, it's the put it back together where I'm significantly challenged . They can toy with me by throwing a couple extra parts on the bench I had toyed with the idea of going into business for my self. I was leaning toward demolition contracting. We had a company here that tore down the wrong house (correct # but one street over and occupied), lost control of a smoke stack and took out the corner of an adjacent building - no injuries, and lost a wall and killed a pedestrian, all in abut 2 years. He is still in business today but only because one of the local big dirt guys bonded and insured him for some years. I figured if he could survive, I could make some decent money by working smart and most importantly safe. I volunteer occasionally for the local tourist RR. I really enjoy working with the Chief Mechanical Officer as his helper. He's just a young guy but his knowledge is amazing. I can be disassembling something or helping reassemble and he explains every step why he's doing what. I couldn't reassemble anything complicated on my own but understanding the why is fascinating to me.

  18. #18Shimmy12018-12-29 11:05

    And there is a very special place for those guys when their number is called. Deliberate, malicious dishonesty is as bad as you can get, and that is what this is.

  19. #19kenh2018-12-29 12:57

    A number of for PSD owners have been billed for 4-6 glow plugs when the wiring fell apart under the valve cover. Very rare for that number of G plugs to quit