Hi all,
Ok this is going to take a bit of explaining.
1990 2.9 Ranger 133k miles. very clean.
Previous owner put new injectors in. But siliconed the intake gasket.
I get truck, runs weak but not to bad.
changed fan clutch (frozen), Exhaust gaskets (both sides leaking). This also when I found the dist was crazy loose. cant believe it ran, much less as well as it did.
Go to smog, HC real high, smog guy says look for vac leak.
2 1/2 cans later, I cant find a leak that would make the engine alter.
Go back and with the sniffer in we found the lower intake was leaking.
Change intake (upper and lower), found silicone and one loose forward bolt.
Thinking I found the problem.
Well NOW, I have a pinging /rattling. Sounds like a coffee can of rocks.
Consistently happens at 2400-3000 rpm
At first it sounded so bad it sounded mechanical.
Listened all over the engine and narrowed it to number 5 and 6 cylinders in the valve cover or at the intake valves. Found nothing!!!
Why I think its ping is cause if the spout conn is pulled the noise almost goes away.
Base timing is 10* with spout out.
I have put new cap and rotor, plugs, TFI.
Spout circuit is good, and no codes.
I even retarded the base timing to see if that helped. It didnt.
could it be the PIP unit?
computer is controlling timing when the spout is in.
with a base of 10* timing goes to 25* and is steady in till a throttle blip.
Timing does not change when ping starts happening.
Im dying here guys. Im out of time, money and patience.
Please help me save my little Ford
Thanks

 

so it looks like I wasnt clear on what rpm this happens and that it goes away after 3000 rpm. or that I cant hear it at that point.
I can make it happen no load in the driveway and really seems the same on the road with a load.

So I did check that it does not happen when cold,
and "clear flood" is working.
when driving warmed, it kind of clears up when I do go WOT.
But at that point im passing the RPM range that it makes noise. But it does sound like it would be lean cause WOT seems to clean it up some.

I know the 2.9 has a "rumble" when lugged down.
But I can do this parked in the driveway with no load.
Very manipulatable, always at 2400, stops around 3000-3200.
Not there with spout out or when cold.

I will try advanced and see what that does for it.

I know filter should be changed, just havet got to that yet. and it clears up at upper RPMs but is weak and stops pulling around 4500-5000.

I forgot to say I did a Sea foam on intake (wasnt very dirty inside when I did the intake gasket) and oil treatment ( had a lifter start sticking, but that seems better now).

The CEL does work, but has never come on during this (except when I unplugged the MAF to check if ecm was doing its thing)
Thanks
Im going to go adv timing and see what that does.
Check back later

 

Sounds like the previous owner may have done some work on the engine. You may have to see if the engine is timed correctly mechanically before you proceed any further in your diagnosis.

 

I chased this problem for two years. Replaced just about everything and still the ping until my timing belt broke. Replaced it no more ping.