4.9l ford no start

Does the Vheicle speed sensor need to be hooked up? Should I jumper the wires on the EEC (#3 to #6) if I did not connect the VSS?

No & no. The speed sensor won't keep it from starting/running. Speed sensors are used for speedometers, fuel trim, cruise control, and trans shift points.

Having retrofitted a 5.0 EEC-IV system to a 351C, I know that the VSS is not essential.

You say that the fuel pump comes on. Does it stop after about two seconds or does it run continuosly with the ignition on?

If the pump stops, then the EEC is alive. If it runs continuously then the EEC has crashed.

My guess is that there is a problem with the wiring from the distributor/TFI to the EEC. The EEC needs to get the PIP signal from the distributor to know that the engine is turning and to time the injectors.

The TFI can generate spark with the EEC dead, so the fact that getting it to run by spraying fuel manually doesn't mean much.

You fail to mention the ECT and ACT sensors, but none of them are essential to start the engine.

The EEC can run with most of its sensors missing, and it can even run with the processor dead. It goes into LOM mode, where there is analog electronics that generate a fixed 50% injector duty cycle and you modulate engine speed with the amount of air passed by the throttle. It will still need the PIP signal from the TFI though

Do you have a good ground path from the computer to the engine?

Are all the computer harness grounds bolted onto the block? Usually near the dipstick? I have seen one dropped wire there too many times on engine swaps.

Mike

On Jun 13, 8:57 am, Mike Romain wrote:

To all, for your responses...Thank you...I purchased a set of niod lights and determined that I did in fact have a flashing light at all of my injectors...with 60 psi fuel pressure on the rail, this mother should start...But no..The only thing left to check was the injectors themselves. As I am a meticulous fellow, I checked and double checked every wire from every sensor to the ECC and elsewhere, before I wrapped the new harness. I was certain I did not leave anything out. I had fuel (to the rail), spark , crank, everything should be correct (after all this is not rocket science. If a guy can read a schematic and follow some lines and wire color codes these EFI swaps are a snap...) So....This afternoon I pulled the fuel rail and injectors and using a battery and a couple test leads I attempted to manually open the injectors and none of them worked.!!! thirty minutes in a denatured alcohol bath and compressed air in both directions with power to the injectors I had them all working just like a song. I re- installed them and replaced the upper manifold, and viola!! The engine fired and purred like a kitten on the first crank....Dirty, stuck injectors...Who would have thought??? All problems solved... This was a cool project...Next...My "65 Ford short box step-side will be getting a '95 EFI 351W can't wait to get that one going....Hopefully I'll find all the parts I need before the end of summer and I have to go back to work:)