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Thread: Test those injectors

  1. #1
    Senior Member Carroll Shelby ShadowBolt's Avatar
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    Test those injectors

    The 55 has been way down on power ever since I installed the current engine. At Cresson it would not idle but we thought it was running okay at WOT. After Cresson I installed new O2 sensors and assumed we were good to go. At Hallett it got to the point where I could no longer even stay close to anyone. Several times I passed a car going into and through turn one only to get passed back 100-150 feet after track out. On Friday morning during first practice I told Jay the car really felt good and I was not even having to shift into fourth down the front straight. Of course I did not realize the reason was because we were so down on power. I only had 60 to 90 psi compression and that was it. I assumed it was going to be the valves or an issue with the heads (hoping). After getting home from Hallett I pulled the engine and heads and the cylinders looked like shit. I took Pranav's advice and sent my injectors to have them checked after sending pictures of the block with the heads removed to DSS Racing. DSS said it looked like my engine had been fuel washed. I never even heard of that. Turns out one of the injectors was wide open all the time! Others had issues but they got them all cleaned up and working correctly. Well worth the money. Those injectors cost me a $3000.00 short block. At Hallett our eyes would burn so bad we could barely finish a 25-30 minute race. Injector RX (injectorrx.com) in Houston turned them the same day they received them. I hope like hell this is the end of my engine issues for at least four or five years or I will be joining Marshall as a spectator.


    JJ

  2. #2
    Senior Member Carroll Shelby
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    Still need to get the A/F gauge working on it but glad you had the injectors checked and found at least one known issue. Don't need you joining Marshall and Celine.

    Anyone have a place like that who does diesel injectors?
    Bryan Leinart
    CMC #24

  3. #3
    Senior Member Grass-Passer Suck fumes's Avatar
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    precison power is in del valle and does injector cleaning as well.

    (512) 751-5018
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  4. #4
    Senior Member Carroll Shelby Supercharged111's Avatar
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    I seem to recall there being an injector balance test the even the EECIV Fords could perform without any special scanners. My neighbor's Snap On Solus can also perform a balance test. Jerry I think this would have flagged for you right away. The LT1 injectors are known junk, I should probably get something decent in there before next year's dyno.
    RM CMC Director

  5. #5
    Senior Member Carroll Shelby RichardP's Avatar
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    Quote Originally Posted by Supercharged111 View Post
    I seem to recall there being an injector balance test the even the EECIV Fords could perform without any special scanners.
    The biggest (only?) advantage of the engine Jerry is running is the computer's diagnostic capability. With the simplest of scanners, you can tap into what the engine is trying to do and the issues it is having. It's not clear what codes would be set in a race car that spends most of it's time in open loop? If you ran an engine with a stuck injector on the street, you would get codes for air/fuel out of range per bank, your fuel trims would be maxed out, and there would probably be misfire codes specific to the cylinder.

    If there is something suspect with a motor, it's easy to check the computer. Sometimes it's useless information but it can be very helpful. Also, I don't know how Jerry's car is set up, but I've seen so many racecars where the standard procedure is to dump all power with the main cutoff switch when you park it. I still struggle with Dan on that one. That erases all sorts of good information and resets fuel trims, etc. Not the best plan.

    There is one thing to keep in mind with using an injector shop for diagnostic work. Almost all of them first clean your injectors and then test them. If there is something physically wrong with your injectors it will be flagged. If your problem had to do with clogged injectors, they could easily come back as all good.


    Richard P.

  6. #6
    Senior Member Carroll Shelby
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    Quote Originally Posted by RichardP View Post
    The biggest (only?) advantage


    Richard P.
    Have you seen the power curve?
    Bryan Leinart
    CMC #24

  7. #7
    Senior Member Carroll Shelby ShadowBolt's Avatar
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    Quote Originally Posted by RichardP View Post
    The biggest (only?) advantage of the engine Jerry is running is the computer's diagnostic capability. With the simplest of scanners, you can tap into what the engine is trying to do and the issues it is having. It's not clear what codes would be set in a race car that spends most of it's time in open loop? If you ran an engine with a stuck injector on the street, you would get codes for air/fuel out of range per bank, your fuel trims would be maxed out, and there would probably be misfire codes specific to the cylinder.

    If there is something suspect with a motor, it's easy to check the computer. Sometimes it's useless information but it can be very helpful. Also, I don't know how Jerry's car is set up, but I've seen so many racecars where the standard procedure is to dump all power with the main cutoff switch when you park it. I still struggle with Dan on that one. That erases all sorts of good information and resets fuel trims, etc. Not the best plan.

    There is one thing to keep in mind with using an injector shop for diagnostic work. Almost all of them first clean your injectors and then test them. If there is something physically wrong with your injectors it will be flagged. If your problem had to do with clogged injectors, they could easily come back as all good.


    Richard P.
    Richard,
    We got all kinds of codes. Lean bank one, Lean bank two. Never anything about running rich.....all the while smelling raw fuel. Never missed at all other than at idle. During races it was just down on power with the fuel smell. The car was throwing all kinds of different codes but never the same one back to back (and we were clearing the computer).


    JJ

  8. #8
    Senior Member Carroll Shelby ShadowBolt's Avatar
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    From the paperwork I received with the cleaned injectors they test them before and after cleaning. There was a note that said

    Injectors would not fire at preflow.


    JJ

    I just called Injector RX and they said they were so dirty they could not even test them prior to cleaning them.
    Last edited by ShadowBolt; 09-25-2019 at 12:46 PM.

  9. #9
    Senior Member Carroll Shelby RichardP's Avatar
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    Quote Originally Posted by ShadowBolt View Post
    We got all kinds of codes. Lean bank one, Lean bank two. Never anything about running rich...
    Fascinating stuff. Maybe dumping raw fuel overwhelmed the sensors?

    Richard P.

  10. #10
    Senior Member Carroll Shelby RichardP's Avatar
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    Quote Originally Posted by ShadowBolt View Post
    From the paperwork I received with the cleaned injectors they test them before and after cleaning. There was a note that said

    Injectors would not fire at preflow.


    JJ

    I just called Injector RX and they said they were so dirty they could not even test them prior to cleaning them.

    Interesting. The injectors worked fine after cleaning? You didn't have to replace them? Why did they get dirty is probably the bigger question, then. Do you have a non-stock filter setup? Maybe something weird happened in all your fuel tank messing around?


    Richard P.

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