The Yellow Top and XF2E are both Bosch/Ford fuel injector used by Ford on their modular Mustang engines. Both have fuel flow ratings of 22lbs/hr (pounds per hour) at a constant pressure of 43.5 psi (3 atmosphereic bar/pounds per inch squared).
These statistical numbers are identical to the original equipment injectors for all 1985-91 L98 350cid engines.
The tested resistance or impedance is 14.5 Ohms. Which means the high-resistance Bosch injectors are 100% compatible wihtout any modifications to any part of your L98 electrical system.
BOSCH YELLOW TOPS: What you get for your money:
Fiveo made a special purchase of these injectors "new - from old stock". All have been ultrasonically cleaned, then, for added assurance, back flushed to remove any dirt that may have settled into the injector interior. All have been leak tested to be certain the injector can maintain 60psi of pressure along with a spray pattern test and coil resistance checked. If the injector passed these tests, each one got a static flow test at a constant 44psi. Then a dynamic flow check was performed - this final test simulates actual running conditions. If the injector passes the flow tests it got all new filter basket, orings and pintle cap. And finally a good polishing and a clear coat sprayed on (on some sets the metal bodies have been sprayed black) and hermetically sealed to increase shelf life. (Our photo injectors may have been unpacked to better show the parts).
Some noteworthy installation specifics.
Performance issues with your Tuned Port Application?
Is the vehicle equipped with the factory GM Multec Fuel Injectors? (GM Multec Injectors can be identified by their larger smooth body: Multec injector.
A common failure with the Multec injectors is shorting of the injector coil. The injector resistance should be between 12-14 ohms.
These vehicle are also batch-fired. Meaning that the injectors are wired in parallel, four (4) in each batch.
In a parallel circuit the total circuit resistance is less than the lowest resistance device in the circuit.
The driver inside of the ECM, a small transistor, is used to turn-on the injectors during engine run.
The driver is designed to handle a certain load. With four injectors wired in parallel at 14 Ohms each and the system voltage operating at an average of 13.5v, the approximate current load will be 3.3 amps.
If one of the Multec injectors shorts out; say down to 1.2 ohms, then the current draw on that circuit will exceed 10 amps. Well beyond the system design.
This results in the remainder of the injectors on that bank not firing.
Many times I have seen these vehicle have hard starting issues, rough run and stalling with failure to restart.
An ohmic check of all the injectors should be done if you are having any of these driveability symptoms.
I recommend to not reinstall the original-design Multec injectors. But to either install Ford/Bosch Yellow Top or one of the new Design III fuel injectors.
Both will fit the vehicle with little or no modifications. With the new Design III XF2E, the wiring harness connectors will have to be used. I recommend that you cut off the old connectors and properly terminate the new connectors rather than plugging in the adapters.
(With either you will not use the old metal retainer clip).
The new style injectors are much more linear and will provide many trouble free miles of proper engine performance, I highly recommend them!
Regards,
Scott Brown, Owner, Van Gordon & Brown, Claremont, California
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