Hi,

I am trying to help a friend of mine fix his 2000 f150 4.6l as he has been having some issues with it.

The problem:

Engine suddenly got a lot quieter, ABS module is making a whirling noise for about 1.5 seconds after he starts the truck, the truck (according to him) has started to shift differently, rough idling and there is a big loss of power. No CEL codes have been thrown so we are kind of working in the dark.

What we have done so far:

Cleaned all sensors (MAF, TPS, IACV), ran an engine scanner just in case the CEL is broken, replaced fuel filter/air filter, changed plugs, oil change, check the voltage given to the MAF and checked the grounds to the MAF (Some of these were done just because we figured it was time to do them).

What we have accomplished so far:

Better idling and apart from that, jack all!

This is really starting to bug me now as we cannot figure it out.

Any tips on where to look next or what could cause any of the above would be great.

Thanks,

Ollie.

 

Check fuel pressure.

 

That was going to be my next move, thanks.

 

Good, then check the EGR valve. Just pull the green line and tap it w/screwdriver handle while it's idling.

Converters next. Check them with an infrared heat gun. Sometimes they can even glow at night if they're 75% plugged.

Hope he has Motorcraft spark plugs in their. If not, that can compound problems.

Motorcraft.
Denso Iridium's.
NGK.

That engine runs the best with either of those brands. It may run with others, just not at full potential, sometimes not even close.

The Fine wire Iridium's are as good as you can get.

Good Luck

 

Ok, so motorcraft plugs, EGR is brand new, so I guess the next thing is to borrow an IR Gun and see if the converters are clogged.