348 crank no start | Page 2 | FerrariChat

348 crank no start

Discussion in 'Technical Q&A' started by mebozart, Oct 21, 2022.

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  1. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    13,673
    San Carlos, CA
    Full Name:
    Mitchell Le
    If that waveform in the picture you posed is measured at the injector then the injector never is going to turn on. There is never 12V across the two pins to drive it on. Something is keeping that point from going to ground.

    Here is what you can do for me.

    Use two oscilloscope probes.
    Attach one at the signal source where the ECU connector is
    Attach the second one at the injector where the signal ends up
    Show both signals at the same time on the scope you have, Post a picture of it
    Disconnect the ECU and the injector, measure with a DVM the resistance of that one wire, post that result.

    The difference voltage between point 1 and point 2, divided by the resistance value, is the current flowing through that wire. We want to know where that current is going.
     
  2. Christof

    Christof Karting

    Jun 29, 2014
    185
    Australia
    Check all the grounds - even put another direct from battery to engine just in case to rule that out. Also if you have the old crank sensors and it did start before, put them back in. Also double check the connections on them. Lastly, was the engine timed correctly when the timing belt went back on
     
  3. mebozart

    mebozart Rookie

    May 16, 2022
    45
    Bloomington, Indiana
    Full Name:
    Matt Bozarth

    IT LIVES!!!! After all of our checking, testing, mistakes and chasing our tails we found it. It was the Injectors. I don't know how this can happen but all 8 injectors were not firing. These were the stock injectors that were all virtually blocked with debris from the fuel tank. I had them sent out to be sonic cleaned and the company sent back a page that showed flow ratings and gave them a clean bill of health. I don't know if they were stuck closed or if there was some sort of voltage issue that somehow fried them but it runs with new injectors. In the beginning I thought there was no way that all 8 were bad. It just seemed to hard to believe but that was the case. I purchased new injectors and it fired right up.

    It does idle very high so any comments about adjustments that I should work on after putting the engine back in would be appreciated. I did have the entire intake manifold apart to clean and paint it. I'd assume that the TPS needs adjusting. Anything else I should look out for? Thanks for all the help thus far!
     
    Qavion and Flyingbrick242 like this.
  4. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    13,673
    San Carlos, CA
    Full Name:
    Mitchell Le
    There is a procedure in the WSM to adjust the idle.

    Good luck and great to hear.
     
  5. Qavion

    Qavion F1 World Champ
    Silver Subscribed

    Feb 20, 2015
    14,534
    Sydney
    Full Name:
    Ian Riddell
    I wonder if it was the guys who cleaned and checked your old injectors who broke them them? Maybe someone set the test pressures too high or used the wrong solvent for cleaning. This is the second case I've heard of.

    Did you have problems finding injectors?
     
  6. kryten2001

    kryten2001 Formula 3

    Well done on finding injectors. I recently tried to find new ones for my 355 and couldn't find anything...

    Mine were also a bit blocked, but thankfully after a VERY long ultrasonic they came good - nice spread and all within spec.

    This can happen if they sit around for a long time without fuel going through them. Things gum up... A lot better than a carbed car mind you, they can be a nightmare.
     
  7. mebozart

    mebozart Rookie

    May 16, 2022
    45
    Bloomington, Indiana
    Full Name:
    Matt Bozarth
    The Bosch number for the factor injector is 0280150731. I put that into a parts interchange and found a Delphi number of FJ10093. If you look at the application listings for that, it shows various FORD and Lincoln applications. All are for a 4.6. Looking through the forums people reference Mustang injectors. One member said he had problems because the OHM rating is different. I rolled the dice and bought injectors that are for a 92 Lincoln town car. They do OHM out at 14.9 but we put them in anyhow. I also have my parts vendor to stand behind me should it create some sort of an issue. I'll let you know how it goes.
     
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  8. Qavion

    Qavion F1 World Champ
    Silver Subscribed

    Feb 20, 2015
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    Sydney
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    Ian Riddell
    Good to know. My first attempt at finding a replacement wasn't so successful (the flow rate was just too different and beyond the capability of the ECU to maintain the stochiometric ratio). My tech's vendor gave us a refund. Ultimately, I went OEM (but only needed a single injector). Spray pattern is another issue. Even if the flow rate is good, you don't want most of the fuel ending up on the walls of the intake tract.

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  9. Ferrarium

    Ferrarium F1 Veteran
    Sponsor Rossa Subscribed

    Jul 28, 2018
    5,728
    Central NJ
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    Eric

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