Getting the most out of the Ford 2.3L

	2.3L Ford EFI Modifications - Fuel Injectors! The stock fuel injector for a 1992 Ford Ranger is rated at 14 lb/hr. You can swap in a better flowing fuel injector for better performance. I have been working on increasing the air flow through the engine and consequently, I should increase the fuel flow appropriately. I just returned from a 3000 mile (5000 km) 4 day road trip to Santa Fe New Mexico pulling a 1300 lb trailer. When you are behind the steering wheel for 55 hours, you notice some things. One thing I noticed was that when I was going up a steep hill with my foot to the floor, I could slowly back off the gas pedal without slowing down. At one point, the truck would sometimes actually accelerate! This got me thinking. If I have the pedal to the floor, the butterflies on the fuel injection are wide open and I'm getting as much air as the engine can handle. If I back off the gas pedal, the butterflies are closing and less air is allowed in. If the truck starts accelerating when backing off the gas pedal, that means that we're getting the ideal fuel/air mixture and the most power. At wide open throttle the engine is not getting enough fuel - the fuel injectors can't supply enough fuel. I need bigger fuel injectors! I tried a little experiment. I figured that with my foot to the floor on the hills, the engine was running lean (not enough fuel). So whenever, I started up a hill with my foot to the floor, I slowly feathered the gas pedal back until the truck started slowing down, then pressed on the pedal til it just maintained speed. Doing that I managed my best gas mileage for the trip of 27.5 mpg versus 23 to 25 for the rest of the trip. Selecting a Fuel Injector This webpage called Choosing the Correct Fuel Injector for your Application (which is taken from the Accel performance fuel injector data sheets - linked below) has the mathematics for selecting a fuel injector based on your hp requirements. I ran the 2.3L specifications through the magic formulas and used BSFC of 0.45, number of injectors = 4 and a duty cycle of 0.80 for a 100 hp engine. They indicated that I would need a stock 14 lb/hr fuel injector. If I wanted 130 hp from the engine, using the same BSFC and duty cycle, I would need an 18.3 lb/hr flow rating. Obviously, the flow rating of the stock fuel injectors is limiting the amount of hp the engine can produce. I ran across the Accel performance fuel injector data sheets (pdf) and they list 3 fuel injectors for the 2.3L Ford engine: 14 lb/hr for stock replacement 15 lb/hr for Level 1 performance 17 lb/hr for Level 2 performance Unfortunately, they don't expand on what they mean by Level 1 and 2 performance. This leads to my research, I've found that you cannot just slap on any old higher output fuel injector and expect it to work. The size of the fuel injector and the mass air flow sensor should be matched together within the limits of the computer's (MCU) programming. If you replace any of the components and they are out of the limits of the MCU's programming, you will end up with a poorly performing engine. From my research, there should be no problem in upgrading to a 15 lb/hr fuel injector without reprogramming the MCU. Now interestingly with the Accel fuel injector data sheets, it limits the available fuel injector flow rate to a maximum of 17 lb/hr. Why only 17 lb/hr and not higher as in the other engines Level 3 to 9 injectors? (Yes other engines have up to 9 levels of performance injectors!) This leads me to believe that the maximum flow rate that is within the MCU's programming limits is 17 lb/hr without changing any other component. Level 1 - 15 lb/hr fuel injector sources 15 lb/hr from one of the following 2.3L engines: 95-97 Ford Ranger/Mazda B2300 91-93 Mustang 2.3L 92-96 Ford Escort Tracer 1.9L 89-94 Taurus, Sable 3.8L 91-95 Thunderbird 3.8L This should give you 7% increase in fuel to the engine and hopefully 7% more power! I haven't done this yet but expect about 7 to 10 more hp at WOT (wide open throttle) which I use going up hills (I live next to the Rockies). Level 2 - 17 lb/hr fuel injector sources There are no stock Ford products that use the 17 lb/hr fuel injectors, but you can use the same Accel 17 lb/hr fuel injector listed as stock replacements for the following GM products (they are 100% compatible): 94-98 Achiva, Ciera 3.1L 93-95 Camaro, Firebird 3.4L 93-97 Cutlass Supreme 3.1L 97-98 Cutlass 3.1L 94-98 Century, Regal, Skylark 3.1L 94-96 Corsica, Beretta 3.1L 94-99 Grand Prix, Grand Am 3.1L 95-99 Lumina, Monte Carlo 3.1L 97-99 Malibu 3.1L With a Stage 2 fuel injector, I would expect 21% better fuel flow over the stock 14 lb/hr fuel injectors. Hopefully, this would translate into a 21% increase in available horsepower or roughly an increase of 21 hp! 19 lb/hr Fuel Injector - NOT RECOMMENDED Most all Ford 5.0 V8s with EFI come with 19 lb/hr fuel injectors and are readily available and inexpensive. I figured that with all the intake and exhaust work that I did, I could use the 19 lb/hr fuel injectors. I picked up a set of 4 for $100 off of ebaymotors. New Fuel Injector Results I went overboard and installed the 19 lb/hr fuel injectors and the results were not immediately as dramatic as I expected. It took about 100 km for the computer to learn the new settings. There is about a 20% increase in hp (20 hp) and lots of acceleration. The truck accelerate better and the bottom end is better at 1500 rpm in all gears. I haven't really tried the top end cause I just don't run the truck up there. The truck is now much more drivable. I don't have to downshift on hills that I had to downshift from 5th to 4th or 4th to 3rd anymore. Whenever I shift gears, I feel a little kick of power as the new gear engages - this includes when shifting to 5th. I can accelerate in any gear starting at 1200 rpm. Oddly, the engine now idles at 600 rpm where with the stock injectors it was idling at 750 rpm. I'm happy to cruise along at 1800 rpm and can accelerate when the pedal is pushed. Note: I've received quite a few emails where readers had swapped to 19 lb injectors and weren't as lucky as I was. They had bogging problems, difficulty idling and rich conditions at full throttle. For now I'm going to say not recommended - I just got lucky. Stick with 17 lb injectors. How to swap out a fuel injector Here is a page that gives some tips on swapping out the fuel injectors After failing to get a replacement gasket that goes between the throttle body and intake manifold at the local parts sources, I went to the Ford dealer. According to the local Ford dealer, the gasket is obsolete and no longer available BUT he did have the last one in stock. I've scanned it in so that if you need one, you can make one from the scanned image First you must have a repair manual for your 2.3L that describes how to do it and how to release the fuel pressure from the fuel injector rail. How you do it, depends on what tools you have. I've included some pictures of my 2.3L taken apart and some notes on the pitfalls that you may encounter. Disconnect the battery positive lead Unplug the circled connectors and vacuum lines. The connectors are tricky as they have snap-on clips on both sides. Use a small screw driver to open each side of the snap clips. Undo the bolts on the EGR valve, Intake manifold and the fuel rail ONLY when the fuel pressure is released. There are two bolts on the EGR valve to remove. The bottom one is a pain and I had to play with it from the intake manifold side. The intake manifold has 5 bolts holding it in place of which 3 are threaded studs with an extra nut on to hold other things. So you have to unscrew 3 nuts before you can unscrew the bolts/studs holding the intake manifold. Once the 5 bolts/studs are removed, you should be able to swing the upper throttle body unit on top of the master cylinder like in the picture. Upper throttle body swung out of the way over the master cylinder Carefully disconnect the fuel injector's electrical connectors. They are similar to the previous ones with two clip on latches on either side. You can rotate them to make it easier to remove. Mark each connector with the cylinder number for re-installation. Fuel Injector connectors You MUST release the fuel pressure on the fuel injector rail before removing the 2 mounting bolts! Otherwise you will have up to 45 psi of gasoline spraying all over the place - this is a BAD thing. Consult your repair manual for a safe method of releasing the fuel pressure. There are several methods and each method is dependant on what tools YOU have available. Location of fuel rail Once the fuel pressure is released, remove the two bolts holding the fuel rail. Place a rag around the fuel injectors because there will still be some gasoline left in the fuel rail. Then gently rock the fuel rail to release the fuel injectors from the intake manifold and fuel rail. The fuel injectors are "squeezed fit" in to both the intake manifold and fuel rail using just rubber O rings. Apply some clean motor oil to the new injector O rings and carefully push the injector into the intake manifold. Once all the injectors are in the intake manifold, then push the fuel rail onto the injectors. It's not too hard to do. Finally screw in the 2 mounting bolts, tighten and install the fuel injector electrical connectors. Re-install the upper throttle body in the reverse order that you removed it. Ditto for the connectors. Connect the battery positive cable and fire up the engine. IMMEDIATELY look for fuel leaks and be prepared to shut down the engine. You will have 45 psi of fuel squirting out on a running engine, so if there is a leak, you will not have much time! Tips and Tricks If you have some tips and tricks that squeeze a little more power out of your 2.3L Ford and you want to share them, contact me at: Return to the Getting the Most out of your Ford 2.3L Website