Mechanics

88 BRONCO BIG BODY

1988 Ford 500 • V8 4WD Automatic •

My bronco had a regular 5.0 in it. I have swapped it with a 89 mercury 5.0 ho. I used my old 5.0 oil pan, timing cover, water pump, manifolds, valve covers, fuel rail, injectors, upper intake and lower intake, all sensors, wiring, and ecm. The new ho has a different firing order but wont run properly with it. If I use the non ho firing order it will run better but not properly. I have lots of power but at low speed its got a dead miss and it idles like a car with a big stall cam and sometimes will die. Do I need the ecm for the ho or the 19lb fuel injectors that the ho normally runs. Or have I got other issues? The parts store say that they both call for the same distributor. I am thinking that my ecm wont allow the fuel injectors to fire with the ho firing order. I need some real advise. Every one said this was impossible to swap but I have came this far and have it running. Hate to turn back now. Could I cross wire my injectors to the ho firing order? I also welded the smog pump lines on the back of the block. Thanks for your time!
Avatar
Bobby payne
January 21, 2011.



Check out the related content below while we wait for the question to be answered by a professional mechanic.