I have a 94 f150 4.9 e4od that i've gone through and replaced the intake, vave cover, side cover on side of block, throttle body, exhaust gaskets. Replaced the egr and exhaust tube with new egr position sensor, iac valve, tps, oxygen sensor. removed injectors and soaked in fuel injector cleaner and manually cleaned and back flushed replaced all o rings , filters, and pintle caps repaired a bunch of connectors replaced all vacuum lines. plugs wires new dizzy new icm front fuel pump fuel filter seafoamed multiple times it runs 80% better compared to when I originally got it.


Engine has 333,000 miles I know its tired and does have blow by, the concern I have is that when started up cold I have what seems to be a misfire but no codes for it during koeo or koer passes with 111 But after it warms up the misfire seems to go away exhaust seems to smell a little like gas so i put the egr block off plate and it runs better but the misfire is still there when cold. Other than a rebuild what else is there to look towards? Head? valves sticking? what or how to check ? Thanks for all info has helped a lot on diagnosis for the past year awesome people on here with a plethora of info.

 

Here's something to check that "MAY" be causing you your grief.
Click and read :A9x ECM's (and same years ECM's) Failures Due to Age

Failing capacitors will cause "spikey" voltages within your PCM. The PCM "pulse grounds" the injectors.

Just something for you to check.


Bob

 

I did forget to me tin I did have the capacitors replaced but thanks for the input

 

Time for a compression test.