Does anyone know if there is a way to check the injectors on a 1993 F150 w/a 5.0. I am still having a problem with spark knock and was wondering if my injectors are going bad. It has 172,000 miles on her and I have tried the sea foam, lucas products, changed several parts and still spark knocking.

The other problem that I am having is when you start it after it has set for awhile there is a slight vibration that comes and goes until it comes down off the fast idle. Any thoughts? Thanks

 

change the EGR valve

 

the egr valve seams to be working.

 

try putting a new timing chain and gear set on it. The chain is bound to be stretched out quite a bit by now with the mileage you have. This is the only way to be sure you have correct cam and ignition timing. Good luck!