Timing seems off

[baddawg]

It seems like since I replaced the fuel pressure regulator the timing/ignition slightly advanced. I have left the battery diconnected over night allowing the ecm to reset. I have checked all six cylinders and they are clean and the engine isn't throwing any codes. I replaced the plug wires with new set from Ford. No difference.

Prior to the fuel pressure regulator total failure it would occasionally partially fail and create alot of black smoke. There was never an issue of the ignition/timing being off.

Any ideas?

 

[MrShorty]

What kind of symptoms are you getting that make you think the timing is off?

Timing, though not adjustable on these engines, can be checked. At idle, SPOUT removed -- base timing should be 10 BTDC. Timing advance is checked during the KOER test (SPOUT connected) and should be base + 20 = 30 BTDC.

 

[baddawg]

It feels like a carbourated engine with advanced timing. Mild hesitation and shake to the engine with a bouncing exaust. It's very drivable but there is a definite drop in horse power.

This is all post the fuel pressure regualtor failing. I am about ready to start switching out sensors. I suspect my MAF is intermittantly sending bad signals but have yet to catch it doing so.

Any ideas?

 

[Glacier991]

I guess I am confused. You said you thought the timing was off. Mr. Shorty suggested checking it and explained how, now it is not your thought that the timing is off any longer? Or you just aren't interested in checking it? (It is doubtful it is off in any event). A bad CPS COULD affect the timing though.

Plugs ok? What is your new fuel rail pressure post replacing the FPR? Any codes being set?

ps. Mr. Shorty is your best bet on this board on this problem in all liklihood. Respect his advice (and him)

 

[MrShorty]

If the MAF were intermittently sending bad signal, the computer may have noticed and stored a trouble code. I would certainly pull codes before randomly replacing sensors. This isn't to say that EEC-IV is perfect at catching and reporting all faults, but it makes sense (to me anyway) to ask the computer if it has seen any faults.

Why did you replace the FPR? Running rich or leaking? Do you now have correct fuel pressure? An engine that runs too rich too long will plug the catalytic converter. A plugged converter will make the engine seem sluggish. I would suggest checking engine vacuum in addition to fuel pressure.