Two in depth questions about a 2006 4.0L
 

Hey Guys, I'd scoping out a few things and needs some answers that I can't find after searching.

1) Where is the IAT (intake air tempature sensor) on my 2006 4.0L?
I don't see one & am wondering if it's apart of the MAF??

2) Could someone tell me how far into the combustion chamber a known spark plug protrudes? If anyone has a head off a motor please take this measurement for me!

Regards,
Rich

i believe the IAT is on the driver side of the intake manafold......not for sure though..

Up by the TB all I see is the TPS and the IAC. There are no other wires in that area. Do you mean down in of the runners? (the lightning has one in the runner)

Rich

i was thinking about the IAC Rich.....sorry for the cornfusion:sad:

2001+ Rangers have the ACT (formerly called the IAT) sensor in unit with the MAF sensor. Earlier trucks had the IAT separate from the MAF.

Thanks Bob. I've never seen that before.. but seeing no other wires or sensors that's what I was thinking.

Excellent!

Now, anybody got a 4.0L head & spare spark plug laying around?

Rich

^^^Hahaha.... What are you up to Rich?!?!?

NicksterSVT might. you need it for the measurements? I'll point him this way if i remember.

Well.. I have an agenda. Not going to say what it is until the work is done. Just suffice to say that the plug is a key ingredient to making clean power. ;)

After pulling one of my stock plugs I found that the nose length was 5mm longer than the favorite ones I was going to replace them with?

I've seen so many people report bad experiences with aftermarket spark plugs.
They blame the brand.. and I really don't think it's the plug makeup/brand. I think it's the nose length. I am suspecting that the ones people are using are too short and the spark is shielded.

And so before I setting on a plug.. I need to know how far the plug sticks into the chamber.

Any help is appreciated.

Regards,
Rich

eh i see what your saying but idk. i bought some NGK plugs and ran them for a while, it didnt run bad but it was nothing like the stock plugs so i changed them back.

if i remember correctly the plugs looked pretty much the same.

maybe i am mis-understanding you

If you measure from the chamfer of where the plug bottoms out to the tip of the center electrode you'll see the measurement I'm looking for. The plug I want to use is 5mm shorter than the factory original one.

That means the spark kernal and therefor the flame front as it propigates away from the plug may or may not be shielded depending on how far it protrudes into the chamber.

I suspest that people who have complained of poor performance just might have used too short of a plug. Relying on Autozone or the like to determine which one is a correct replacement is a common mistake people make.

Rich

no thread of the plug should actually be visable in the head. In fact, I think the threaded portion is a universal length.

If your talking about the ground tab I believe that is also a universal dimension.

The differances are in the ceramic insulator on the center electrode. This is what decides the heat range. go here to see how a spark plug works and how the heat range influances spark plug performance.

Brant, I'm 5 steps ahead of ya.. ;)

The threaded portiton of a plug is not universal. They are differing in lengths.

Rich

well probably the best thing to do if you want to cross the autolites to another brand is to actually look it up on the manufactuers website or in their info book

No... because that's only limiting myself to the original design which is an "unknown" to me and what I'm wanting to do. I want to know how far into the chamber the plug sticks. Some are flush by design.. some are proud.

Regards,
Rich

While you are at it index your plugs for a couple cheap hp.

http://www.fordmuscle.com/archives/2000/07/indexplugs/

That little tid bit is older than me! Been doing that myself for over 20 years now. ;)