Thursday, May 26, 2005

We're free! We're free!

Free at last from the clutches of the engine rebuild from hell...

Actually, a great deal of kudos to Virgil Cooley and his team at PEDCO, who stuck with this problem until it was resolved.

It turned out that our low power issue was, indeed, fuel starvation. We're not entirely sure which of the multiple strategies that were last applied worked, although it was probably a combination. Those included swapping the injectors out (again), this time for ones built to the high end of the tolerance for 4775 injectors, and replacing the main fuel delivery line from the bulkhead fitting to the fuel pump. This latter item was a #8, and we replaced it with a #10. Also, it had a braided steel sheath, and there is a distinct possibility it got crimped somehow inside the sheath.

In any case, when we road tested this afternoon, power delivery was much better, and we immediately saw turbo boost readings in the neighborhood of 20psi. Since everything was, at this point, back together, and we were itching to get on the road, we decided to skip the compressed-air-TBS test. It still seems like the DDEC is reading about 5psi less boost than there actually is, but we're not going to pursue that until we resolve the other ECM issues at some later date.

At the moment, we seem to be getting full power, and everything looks good. A hundred miles out from the shop, we stopped to check everything again for leaks, and we have a couple drips of either oil or fuel coming from somewhere forward of the tranny. I will look at those in the morning, when the engine has cooled down.

In the meantime, we are stopped for the night at a truck stop just north of the grape vine (map), which is sort of the ultimate real-world dyno test for heavy diesels. We pulled the hill with little drama, dropping to 40 or so on the really hard parts, but we still passed most of the trucks like they were standing still. Hooh-ahhh.


  1. Sean
    Glad to hear you have apparently solved the problem. Happy motoring. Bill

  2. WOW
    This has really wore me out, I was wondering if you were ever going to get back on the road. That's why I love my BigFoot TT and 4Runner V/8, just cruisin. LOL

  3. Sean
    Good to hear it back on road again with power to spare!

    Wonder, do you have fuel pressure gauge at pump's outlet tap?

    Just ramble-in off for what ever worth;
    Lower exhaust temp gauge & along with lower fuel pressure and lower water temp while hill climbing with turbo boast less than normal psi mean fuel starvation but if fuel pressure is normal then it could be one of many things such you already check DDEC and/or sensors including wiring & injectors & air intake and exhaust restriction.

    Thanks for keeping us informed the happening.

    We all can learn from this ordeal.

    Again thanks for your time to share and you have gotten many supports.

    Sojourn for Christ, Jerry


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