Dropped valve

So my 99 2.7 the converter clogged and I chopped it off in the middle of the road and drove home. That was our last voyage . I’ve replaced every sensor all new exhaust minus a converter and it will not run . It will crank and idle but as soon as you touch the gas it spits backfires and dies. 5 fuel pumps ,clean tank and all the intake sludge removed it still does t run. Could that have caused a valve to stick and make it idle but not run? It’s been down a year and no one can come up with a solution . Oh no codes no engine light .all codes read good no problem and the engine light went off after I whacked the converter . Any ideas before we do a drastic makeover ?

 

Start with a compression test, if all readings are within 10% do a leak-down test. Those 2 will tell you how mechanically sound the motor is. If the leak-down does not show any anomalies I would pull the fuel filter next and blow through that. Next I would pull the valve cover and look for a broken valve spring and check clearances while you are there. If that is ok, ohm the injectors as a go, no go test. If they ohm out correctly I would have them checked for blockage, it kind of sounds like the fuel system has seen better days.

 

Yeah it’s got right at 400,000 miles on it and just went through the fuel system , cleaned the tans new sock , pump , cleaned injectors etc but nothing changed. I’m going to pull compression tonight and go from there. I appreciate the help I’ve been on it to long I need a fresh perspective

 

So the compression test was ok all hit right at 110psi on the instrument gauge I was using. All 4 cylinders were within 2-3 psi of each other. Leak down test up next. I did notice that all the plugs were fouled out as soon as I cranked it the first time on the compression test. This is the 6th set I’ve used during this op.it fouls them every time I try to start it.

 

I’ve never done a leak down test on this 2.7l before what is protocol on this engine so I don’t screw something up?

 

Take out all spark plugs. Roll engine over to TDC #1 compression stroke. If the valve cover is off this is simple, the cam lobs are pointing away from the cam follower. Insert the hose into the spark plug hole and set the pressure gauge to 100 psi and read the leak down gauge. If it shows 80 then you have 20% leakage somewhere. If you hears lots of noise from the oil drain holes, VC off, or from the oil fill cap, VC on, then the rings are leaking compression. Do the same at the tail pipe, exhaust valves leaking, open throttle valve and listen, intake valves leaking.

 

I had a v6 that clogged the converter, backfired and jumped timing.

So while you have it open, should be easy to chéck out. Just in case

 

Roger that I’m going to check it all it needs a new valve cover gasket anyway. Thanks for the help I’ll update when I’m done with results

 

Anyone have a clue what size banjo fittings are on the 99 2.7 fuel hoses from rail to filter? 12mm 14mm or 16mm?