Fuel injector testing...

Discussion in 'Modifications & DIY how-to' started by K. Marx, Apr 7, 2008.

  1. K. Marx

    K. Marx Member

    Hey everyone....


    Allow me to begin this post by apologizing if this question has been brought up before... If it has, please direct me to the appropriate thread.

    Anyway... My question is this: Does anyone know of a shop in the Atlanta area that can test some fuel injectors for me?

    I ask this for two reasons:

    1. I'm working on my bosses' daughter's car (an Escort ZX3) because it runs weak and idles roughly. He has already had a full tune up performed, and brought it to me out of exasperation. He thinks a fuel injector might be bad, and considering everything else that has been done, I might agree.

    He has already had the oxygen sensor, plugs, wires, maf, fuel pressure sensor (there is no regulator on this car), fuel filter, and air filter replaced. I checked the intake and PCV tracts for possible leaks, and while I found one, fixing it did nothing. This being the case, I figure having the injectors tested might be worth it. The car is not flashing any codes.

    2. (Keeping this thread at least somewhat Subaru related.) I might modify my stock injectors for my turbo upgrade instead of buying bigger ones. If I remove the caps, it would be nice to have them flow test just in case.

    Many thanks in advance for any advice or direction. It would be nice to find somewhere local so her car doesn't undergo anymore down time than absolutely necessary.
     
    Last edited: Apr 7, 2008
  2. siegelracing

    siegelracing Registered Vendor<br><b><font color="#666666">bion

  3. K. Marx

    K. Marx Member

    I appreciate the input, Scott.

    How long does it normally take them to get the injectors back to you? If turnaround is not much more than a week, I might go ahead and see if the boss wants me to send them in for a basic service.
     
  4. Batlground

    Batlground Active Member

    RC Engineering has a real high performance fuel injector test rig when you are ready to test your injectors.
     
  5. siegelracing

    siegelracing Registered Vendor<br><b><font color="#666666">bion

    Deatschwerks has a $30,000 dynamic injector testing machine. They are the only ones I know of that have been able to consistently find the STi sidefeeds that are going bad...

    They can do one-day turnaround if requested.

    They have always been AWESOME to deal with.

    Siegel
     
  6. WJM

    WJM Banned

    Did you do a compression and leakdown test? Valves could be out of adjustment...otherwise, if those are in spec then it should be the injectors.
     
  7. Batlground

    Batlground Active Member

    RC found that the machines that were already built were not accurate enough so they built their own....
     
  8. K. Marx

    K. Marx Member

    Thanks for the input, guys.
     
  9. K. Marx

    K. Marx Member


    Actually, I HAVEN'T checked the valve adjustment yet. I don't have a compression tester handy, so I might go buy one, rent one, or just go ahead and remove the valve cover and check the lash. The car has just over 100,000 miles, so I'm sure it wouldn't hurt to adjust them anyway.

    I was pressed for time when I was looking at the car earlier, but I did have a moment when I stopped and thought there was more racket coming from the top of the motor than should have been.

    If time allows he might be bringing it back to me this weekend. I'll see if I can't get the issue figured out. If the valve adjustment doesn't help, I'm also going to recommend that he let me remove the injectors and send them out to be cleaned up and tested.
     
    Last edited: Apr 8, 2008
  10. What year is the car? On some models you can do an injector balance test to see if one is restricted.Also did you do a compression test yet?Did the car start running poorly all of the sudden or was it a slow process.?To me if it was all of the sudden then I would rule out valve clearance as the cause.is there a test port for fuel pressure.?
     
  11. K. Marx

    K. Marx Member

    ^^^

    Apparently the car (a 1998 Escort ZX3) slowly but surely started running worse and worse, so it wasn't a sudden thing. This kind of favors the idea of valve adjustment, so it will be worth a look, I guess. I've never adjusted valves on a Zetec, though, or the valves of many overhead cam engines in general. I'm going to need to do a little research.... I read somewhere that you couldn't just adjust lash by turning a nut on this car; I might have to use shims instead. Not sure about that procedure. I'm a pretty proficient shade tree guy, but if it looks like something weird that requires tools beyond a feeler gauge and socket wrench, I might just tell him to take it to a pro.

    As for the test port for fuel pressure, I'm not sure about that one. I'll have to look and see if I can find one. Since he had an actual shop do the initial tune up, it SEEMS like they would have gone straight to that to see if there was an issue with the pump or pressure sensor, but you never know.

    A compression test hasn't been done yet, but I'm going to try it if he still wants time to bring it by this weekend.
     

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