94 Truck problem solved

[EFISYSTEMS at aol.com]

HI Everyone,
        I first want to thank everyone that took the time to help diagnose 
this thing.  What struck me was someone who said to check the 
basics.......Sometimes people like us get so involved in finding an efi 
problem that we do forget the basics......my biggest problem was I did not 
talk to the customer long enough,,,,,,to  find out the problem started almost 
a year ago but just recently became severe.......well I did find the root of 
the problem during my initial scan.....when key on was applied with engine 
not running and fuel pressure came up...fuel was blowing by one of the TB 
injectors and after disassembly discovered bad o-ring.....replaced and no 
more fuel leak.....still engine would run ok for a few seconds but would 
start running rich......had already done a compression test but turned out 
ok........I won't bore you guys with the details but I had to start thinking 
back what I would do if this had a carburetor on it,,,,and since I had 
verified fuel and spark it must be mechanical......so looked back over my 
compression chart and noticed #3 was the lowest cylinder so I checked it 
again and now was even lower, so checked the one next to it to verify it 
wasn't lower due to temp,,,,,no it was the same so re-checked the #3 in case 
I just hadn't cranked it enough times......guess what now it's 0 
pressure......now can assume broken valve spring or sticking valve.....remove 
valve cover and check....no broken valve spring but intake valve is stuck 
down.....remove rockers and tap top of valve with hammer and... "pling"... 
valve comes up......solution, leaking injector, over a period of a year, has 
built up excessive carbon on top of intake valves and is now causing them to 
stick open randomly.......so anyway,,,those that want can sit back and point 
at the screen and laugh.....I am.......it was actually a good road trip 
looking back on it......cya later
-Carl Summers