I ran a search on here and did not see any info on tuning a 4.2 V6. I had a problem with cranking but not starting. Put in new Motorcraft 100K mile plugs and it started up fine. This am it was cool out and it was hard to start again. I have a 99 with 133K on it. It has the original plug wires, they are dated at the factory. In addition to new wires, air filter what else can I do for a tune up. I did not pull a plug and check my spark, I don't think its my coil. I was thinking of adding some injector cleaner in my tank, anyone had good results with that? Is there a way to check the injectors aside from running a fuel pressure test? I still have not located my schrader valve. Ol Bill said his is near #6 by the fire wall on top of the engine. I did not see anything that looks like a fuel pressure hook up on mine. I have a Chilton but the pictures of where to connect a fuel tester suck, you can't tell where it goes. Could someone please post a picture of the fuel test hookup point on a 4.2 V6? Thanks

 

Anyone out there?