mf 6490 error code 94 help

Discussion in 'Machinery' started by beaconsboy, Mar 3, 2014.

  1. HB1

    HB1 New Member

    Thanks Glaws, you seem to be pretty confident in the relief valve, so the code pops up when it senses a low pressure, or high pressure, or does it pop up whenever it is out off range? What about connections or wiring like what Mursal was saying? I have never replaced it myself, and it looks like I will need to remove some wiring harness and some fuel lines. It will be next week when I get to it. Ill be excited if that turns out to be the problem. Ill take some choke and carb cleaner on the old one. Here is the picture of the old one.
  2. Glaws

    Glaws Member

    Yep that’s the one. If that valve leaks then the rail won’t maintain pressure and you’ll get the code.

    The oil in the harness is due to oil over time, routing down out the rocker cover along the injector harnesses and eventually making it to the ECU connectors. This can cause some odd issues but the relief valve issue is more certain.
    Leonb likes this.
  3. HB1

    HB1 New Member

    I replaced the valve with cleaned one, error code still appears about 15min in.

    Does the code appear right away for you guys or when the tractor warms up? I live in Manitoba Canada, they change to winter fuel in september or so till march april.
  4. There are different flow rates for these pumps make sure 100% you have the correct pump

    Also check fuel lines for restrictions going back to tank often it can be the most simple thing like a bit of straw etc stuck in fuel feed pipe to lift pump
    Also check banjo fittings on fuel lines as this is the first place to choke
  5. Deerefarmer

    Deerefarmer Member

    I just recently fixed one doing the same thing, was mainly getting e 9150 but also e94, replaced electric lift pump, didn't help, blew out fuel line back to tank still got codes, so I pulled the rail relief plug, and lo sure enough it had debris. I put one in that I had cleaned and still got code, finally went to dealer and picked up a new one, presto, problem solved. Lesson to me was probably better off buying new than trying to clean.
    I've also seen e9150 be caused by excessive injector return flow.
    How many hours does your tractor have?
    If a new rail relief doesn't fix it you may want to have the returns measured.
    But I would start at the tank and work up, if you know what I mean, ie process of elimination
    MF 168 likes this.
  6. HB1

    HB1 New Member

    What you are writing makes sense, we have done our homework and its starting to point to some injector problems. I think I will do a leak test.
    Thanks for the posts. I was hoping it would be something easy like seeing that piece of wire in the valve like leonb was showing us :)
    Leonb and Deerefarmer like this.
  7. HB1

    HB1 New Member

    Is there Bosch injectors or others on the market that will be cheaper than Massey's?
  8. Deerefarmer

    Deerefarmer Member

    Ask your dealer about remans

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