addi2 years ago an associate of mine brought in to me a 1999 Ford F-150 that he had just purchased for $500.00. It had only one problem which was a coolant leak from the left head right in the front, there is a 3/4 " diameter water passage than runs through the intake manifold. On the corner of the passage way about an inch down was a 1/2 inch diameter hole corroded through that I assume was because of electrolysis, maybe due to not running proper coolant or any for that matter. Previous owner tried to JB Weld over that 1/2 inch hole with engine still in vehicle. It leaked a bit when cold but slowed way down when warm. Customer requested to find and install a used engine and I would charge him about $2250.00 with extras; water pump, thermostat, rear main seal, spark plugs, oil and filter, coolant, etc.. Engine came with a 90 day warranty only. installed and everything fine but a few oil leaks. He drove the truck for about 5 months and then called me to tell me that it had a miss and no power. I checked at that time and was sure right away that it was a compression issue. removed plugs and checked all 8 cylinders 5 normal, 3 close to 0, different heads mind you not all on one. Previously I told my buddy that the core on the engine was only 75 bucks and if were me I would just pay and keep it because you just never know. When I gave him the diagnosis on the used engine he asked me if I could JB Weld the leak and I told him I would take a look. I discovered, that because it was right on the corner of the head, that if I found a metal bushing that would fit the hole and grind to the proper height, then the JB Weld would not have to close a 1/2 ' gap but maybe a 1/16 of an inch on both sides where the bushing was not meshing. I did this and made sure the bushing height would meet the surface exactly so that any shock wouldn't let the bushing move up or down and crack the JB Weld bond. So this last three weeks on my days off from regular job I did the swap back. This Tuesday night I got it all buttoned up and ready to start and now we have no spark and no injector pulse. We have 45 lbs. fuel pressure and engine sounds good like full compression which I haven't checked yet because to us it was not a mystery motor we purchased from a wrecking yard. Anti-theft light was flashing when cranking so I reset that based on internet info and no flashing light while cranking now. It has the original chipped key that I drove it into my garage with and his wife lost the spare. Have tried the PATS system diagnosis that I found on the internet and didn't really find much but display ended in a T 00 then I pushed the odometer and went to mileage which I think is 200,000 something. To me it appears that the pats system has locked us out even though the light doesn't flash while cranking and just blinks slowly when key is removed. What does any one out there think?

 

both engine still have same crank and cam sensors in them that drove fine before.

 

By the way, crank sensor reads .546 volts AC while cranking, there is battery voltage at both coils, and we have battery voltage at the injectors with key in on position. Have installed new platinum plugs and new premium wires one at a time. I will be 55 years old on February 11th and I did my first valve job in 1976 at the age of 15 years. I've been a mechanic professionally since 1983, previously a back yard mechanic going to college for engineering. I currently work at the Nation Training Center at Fort Irwin, CA as a Tactical Vehicle Mechanic for the last 7.4 years, 4 ten hour days. I run a small repair shop at my home since the 2008 meltdown when we shut our shop down in town and went bankrupt a year later.