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Which fuel injector brand is best?

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  • Which fuel injector brand is best?

    The engine is stock..almost (ported&polished heads with thinner head gaskets). One week with DTC "misfire" located at the first cylinder (easy access..thank God)..spark plug & wire OK...So the culprit was the fuel injector...a pair of tinny hits and 2 "cleanings" help a lot...but I want to replace it.
    I've heard the Bosch ones are pretty good but I would like to follow your advice..
    Thanks in advance for your imput
    Jose L Hidalgo
    97 A4 Pontiac Firebird Trans am with $everal mod$

  • #2
    Hey Doc, good to hear from you! IMHO, replace the whole set. We aren't dealing with an economy car/ beater, we're dealing with a performance machine. Chances are if one injector is fouling/worn, others are not far behind. I've used Lucas, Bosch and have known people that use others they all are pretty much the same, just slightly different features/benefits. Just do yourself a favor and get a flow matched set, install them and reap the rewards of knowing it's right.

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    • #3
      Hey Joe..thanks a lot for your answer...Where to flow match the fuel injectors?...and the dumb question (sorry) Why to flow match them?...If they are brand new..well...they MUST be flow matched..aren't them?..Am I wrong? but they are 42 lbs?
      Thanks a lot again
      Jose L Hidalgo
      97 A4 Pontiac Firebird Trans am with $everal mod$

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      • #4
        The stockers are #24. When you buy an injector, it is rated for a particular amount of flow at a certain pressure +/- a certain percentage. That means at an identical pressure, every injector will put out a potential different amount. Even 1-2% can make one cylinder dead even, yet the next cylinder is lean thereby setting off the knock sensor. Most every place that does commercial injector cleaning does flow matching also. If yours aren't worn out, they can be pulled, cleaned and flowmatched. I personally wouldn't go that route if they have alot of miles (over 30K), it would be better for new ones. Some places even sell the injectors flow matched with a spec sheet included for a few bucks more than the off the shelf ones.

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        • #5
          Thanks a lot again.....I will seek over...
          Take care
          Jose L Hidalgo
          97 A4 Pontiac Firebird Trans am with $everal mod$

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          • #6
            There are not that many different manufacturers of injectors... Delphi (formerly Delco) makes the GM injectors and they are excellent. The only "downside" is the fact that they do not like elevated pressures. But you won't be running elevated fuel pressure unless you have a dry nitrous system, or similar. The stock GM injectors are a "ball and seat" design, with a small plate with tiny holes to develop the spray pattern. As a result, they are reasonably fast acting, fairly resistant to "carbonizing" when the engine is shut down and a few intake valve are open. And the spray pattern is extremely precise, and that is the pattern they designed the intake system for, so there is a strong case to be made for using a stock injector. They are somewhat prone to clogging because of the tiny holes in the distribution plate. You aren't going to find "flow matched" sets though. I suspect some of the repackaged injectors come from GM..... check and see who make the Holley, Accel, MSD etc. injectors.

            Bosch makes a "pintle" style injector, and they are also made by Denso in Japan under license to Bosch. They are available in a huge assortment of sizes, and are sold under a large number of brands. I believe all the Ford and Ford SVO injectors are made by Denso or Bosch. The pintle is good because it can work under very high pressures, and does not clog easilly. The spray pattern is not the same as GM and they are slower to act. The tip projects into the intake runner and can carbonize from excess heat on engine shut down. A lot of people like them becasue you can get a set of 24# or 30# injectors, flow matched for a little over $200. They are a little difficult to fit correctly in the rails, because the clip slots are different than the LT1 injectors. They do flow about 5% more than rated on the LT1, because they are flow rated at a lower pressure. I run 64# Bosch low-impedance injectors at 58psi (=75#/HR).

            Thern is extremely precise, and that is the pattern they designed the intake system for, so there is a strong case to be made for using a stock injector. They are somewhat prone to clogging because of the tiny holes in the distribution plate. You aren't going to find "flow matched" sets though. I suspect some of the repackaged injectors come from GM..... check and see who make the Holley, Accel, MSD etc. injectors.

            Bosch makes a "pintle" style injector, and they are also made by Denso in Japan under license to Bosch. They are available in a huge assortment of sizes, and are sold under a large number of brands. I believe all the Ford and Ford SVO injectors are made by Denso or Bosch. The pintle is good because it can work under very high pressures, and does not clog easilly. The spray pattern is not the same as GM and they are slower to act. The tip projects into the intake runner and can carbonize from excess heat on engine shut down. A lot of people like them becasue you can get a set of 24# or 30# injectors, flow matched for a little over $200. They are a little difficult to fit correctly in the rails, because the clip slots are different than the LT1 injectors. They do flow about 5% more than rated on the LT1, because they are flow rated at a lower pressure. I run 64# Bosch low-impedance injectors at 58psi (=75#/HR).

            Then you get into Siemans and Lucas injectors, but these are more for hardcore racers.

            I would say either factory Delphi injcectors, or the Ford SVO's.
            Fred

            381ci all-forged stroker - 10.8:1 - CNC LT4 heads/intake - CC solid roller - MoTeC engine management - 8 LS1 coils - 58mm TB - 78# injectors - 300-shot dry nitrous - TH400 - Gear Vendor O/D - Strange 12-bolt - 4.11's - AS&M headers - duals - Corbeau seat - AutoMeter gauges - roll bar - Spohn suspension - QA1 shocks - a few other odds 'n ends. 800HP/800lb-ft at the flywheel, on a 300-shot. 11.5 @ 117MPH straight motor

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            • #7
              Fred:
              Thanks for your excellent and complete information..as always !
              Take care
              Jose L Hidalgo
              97 A4 Pontiac Firebird Trans am with $everal mod$

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              • #8
                Sorry for the "sloppy" post..... but there seems to be something in the new bulletin board software that makes "double" entries on some text, and no matter how hard you try, it can't be edited out.

                Fred
                Fred

                381ci all-forged stroker - 10.8:1 - CNC LT4 heads/intake - CC solid roller - MoTeC engine management - 8 LS1 coils - 58mm TB - 78# injectors - 300-shot dry nitrous - TH400 - Gear Vendor O/D - Strange 12-bolt - 4.11's - AS&M headers - duals - Corbeau seat - AutoMeter gauges - roll bar - Spohn suspension - QA1 shocks - a few other odds 'n ends. 800HP/800lb-ft at the flywheel, on a 300-shot. 11.5 @ 117MPH straight motor

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                • #9
                  That leaves the question of how much hp are the stock injectors good for? I'm building a 383 with worked LT1 heads no power adders, will the stock injectors handle that with an additional fuel pump & pressure regulator (I know teh regulator only works at wide open throttle).

                  Hyper

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