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Old 03-30-2003, 08:49 AM
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PigFarmer
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Location: Charter Oak, Iowa
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1986 Ford F150 302 5.0 4x4 installing fuel injectors

I rigged up a shade-tree flow bench to do mine. If you can get your dealer to do it for $15 like franklin2 then this is by far the easiest. I'm a tinkerer (my wife claims I have more time than brains!) so I took this on myself. I took the fuel rail with injectors out and then secured the injectors to the fuel rail with wire ties so they wouldn't blow out when I pressurized the fuel rail. I also plugged the fuel return at the fuel pressure regulator. I used a refillable aerosol can (I think it's called a Hot Shot) that you can fill with any fluid you want and then pressurize with air via a chuck on top. This was plumbed into the fuel feed line. I used SeaFoam fuel injector cleaner which is labeled for use in injector cleaner machines and pressurized the system with an air line attached continuously to the chuck. I regulated the pressure on the rail by changing the pressure at my compressor. I also installed a small fuel filter between the Hot Shot and the fuel rail. I made a couple jumpers to run between a car battery and the injector. One jumper had a momentary switch installed so I could cycle the injector and also I threw a couple resistors in there to reduce voltage. I've heard some guys say you shouldn't run full 12v to an injector for long periods because the coils might burn up. I've also heard it doesn't make any difference as long as fuel is flowing thru to cool them. I played on the safe side.

To test, I ran 40 psi and flowed each injector before cleaning. I used a cylinder calibrated with cc's and simply a clock. I ran each injector for 60 seconds, collected the flow and recorded. I then filled the Hot Shot with a mix of 50% SeaFoam and 50% gas. I cycled this thru each injector multiple times. (This takes alot of time!) I also removed each injector and attached the hose from the Hot Shot and back-flowed them to flush anything out of the filter baskets inside them. I then hooked everything back up and flowed all the clean injectors. My results were that I increased flow by a consistant 10% thru all injectors. Spray patterns all looked consistant as a result too. Before installing the injectors I did replace the O-rings and plastic pintle caps.

This takes ALOT of time but the process was interesting to me and I now know that my injectors are up to spec.

Randy