I have a 2001 Dodge Grand Caravan Sport 3.3L Flex Fuel (145,390) that turns over but has no spark at the plugs. Originally thought theproblem was the fuel pump, so pump & fuel filter were replaced. Also replaced crank and cam sensors, removed coil pack, cleaned and tested for proper voltage. Final step was to replace ECU with remanufactured / preprogrammed ECU (mileage, VIN, OEM part # provided). Replaced ECU but starter would not engage. Bypassed the electronic start by applying power directly to the starter which did engage. Replaced the new ECU with the original ECU and I was able to turn over but without firing. It seems as though there is some sort of safety shutdown on the new ECU or it was not properly programmed for my vehicle. Any suggestions?