Pinging, how to troubleshoot timing?

[MeatMan]

Ok, I'm sure this topic has been covered but I can't find it here on the forum. My 1993 4.0L is pinging under load, either uphill or under prolonged acceleration. Unfortunately I cannot troubleshoot the pinging (I believe due to timing) because I didn't get the Ford Powertrain/Emissions control manual. My question is, since the timing cannot be adjusted according to the Ford shop manual, at least how do I determine what can be the problem with the system controlling the timing referred to as the SPOUT connector?
I read in the Manual that if you disconnect the In-line SPOUT connector, then verify the timing is 10 Degrees BTDC. If there is something wrong with the SPOUT signal, then the engine fires the coils at a static 10 Degrees BTDC. Again I am not sure what the problem is, but maybe this could lead me to an answer?
How does the Powertrain/Emissions control manual address the problem of timing, or should I just buy the manual and troubleshoot myself?

Thanks

 

[wood1]

Welcome to the site.

As many others have found, when the 4.0L get a little older, the lower intake bolts seem to loosen. This allows the engine to ingest oil and in some cases coolant.

Usually a visual check of #5 plug should show oil fouling. The oil being sucked in causes the ping/rattle under load. Lots of people have been able to simply retorque their lower intake and that has taken care of their problems. I did, but found my engine still used a bit of coolant. I eventually changed my lower intake gaskets (years later) and found it was because of the gasket having failed around a coolant passage.

Before you do anything, check plug #5, replace it if it is fouled and retorque (in proper sequence) your lower intake. Literally will only take a half hour thereabouts. You will need a 1/4 universal to get in a couple places but the rest of the bolts are easily accessible.

Let us know how you make out.

 

[MrShorty]

pinging on the 1st gen 4.0 is rarely a timing issue. Two or three usual causes:

1) As noted, the lower intake manifold bolts coming loose. Usually you can simply tighten the bolts to fix.
2) A dirty MAF, causing a slightly lean mixture. MAF can be cleaned, resolving this issue.
3) Carbon buildup in the cylinders. Usually can be resolved with Seafoam or similar product to clean the combustion chambers.

 

[Anime]

There's a good chance the "pinging" is actually valve clatter, too, especially if it's around the 150-200K mileage mark.

The rocker arms on the 4.0L OHV wear down, getting small indentations where they contact the valves. This leads to there being a gap instead of constant contact, and the valve clatter is the result. The only fix is pulling off the valve covers and replacing the rocker arms (or better yet, the whole rocker assembly). Good idea to replace the pushrods when doing so as well. So far it also seems if left unchecked, this eventually results in some of the lifters going bad...and those are not cheap.

It's a good idea to do the other maintenance as mentioned in this thread though, and you might also want to be sure and use 'top tier' or other good brand name fuel with plenty of detergents, dirty injectors and valve deposits can cause air/fuel and combustion issues that lead to pinging as well.

 

[MeatMan]

Thanks, As you guys first mentioned I have cleaned the MAF, and the intake gasket has been recently replaced due to it failing a couple of years ago. I might just use this sea foam, but it sounds like I might have to check my valves, truck has at least 150k on her.

Thanks, Ill let you know how it turns out!