Throttle Body Question

[dmasini]

Does anyone know the stock diameter of the throttle body on a 97 4.0l SOHC? And does anyone have any suggestions for a good aftermarket one?

A friend of mine is suggesting that a bigger throttle body might solve the lifter/piston tapping. He said the combustion chamber might not be getting enough fuel/air mix, maybe because of the KKM air intake on my X. He says it sounds a lot like an octane knock like some older cars have had. Anyone know anything about this? Believe me when I say I have tried EVERYTHING that's been posted in this forum about dealing with the infamous "pinging".

 

[Alec]

I believe stock is 65 mm (but could be wrong). However, as far as I know there aren't any aftermarket TBs for the SOHC.

 

[ton_e_montana]

from what I've read, the larger throttle bodies for the OHV's that you get aftermarket are the same as the stock ones in the SOHC. Alec is right, there is not one for the SOHC.

 

[dmasini]

That sucks... I did find one from BBK but it's 65mm. Is there any reason they don't make a 70mm for the SOHC's that you guys know of??

 

[Alec]

The only reason I can think of that you'd need a larger one is forced induction.

 

[dmasini]

Well that certainly wouldn't hurt anything! hahaha

But you don't think it would solve the infamous ping in any way?

 

[Alec]

don't think so, could actually make it worse.

 

[dmasini]

Really?? Wow... how would it make it worse?
Thanks for the input on this Alec!

And you as well Mr. Montana, say hello to your "little friend" for me...

 

[Alec]

I'm thinking if the stock MAS is a little slow with a larger TB the fuel/air mixture could lean out more, causing more predetonation and/or higher combustion temps.

 

[ton_e_montana]

I've also read here about cleaning the MAS does wonders. There is a writeup on it if you do a search under MAS or mass airflow. BUt you might have tried that already.

 

[dmasini]

Yeah, I've cleaned MAS, called/checked out all the TSB's related to it, ran a higher octane for awhile, tried the Sea Foam, etc......

Granted my X now runs clean, has great response and idlesgreat! But that pinging is just SOOO annoying!

Thanks again for the help guys. Gonna change out the plugs and wires this weekend, maybe that will quiet things down for awhile...

 

[Rhett]

Have you looked at the timing chain TSB?
You have a 97 SOHC and that's the exact year of that problem. And the timing being off could cause pinging.
Maybe 2nd gen SOHC owners can chime in more here, I'm a little outta my area.

 

[dmasini]

I got a Ford Dealership to look up my VIN and see if the recalls had been done. They claim all the timing chain issued had been taken care of before I took ownership.

They told me if I wanted them to check it out again it would involve pulling the engine to check out a variety of issues. I don't want to pay for that kind of labor! Especially from a dealer!

So I changed my oil today and it 's pinging twice as bad as it was before. Not to mention the howling of the IAC came back after cleaning it 2 weeks ago...

I just keep telling myself I could have been stuck with a Trailblazer and I start to feel better!

 

[Alec]

Just a few suggestions that you may not have done:

Injector cleaner through the fuel system
inspect the plugs and wires and maybe change them
inspect the TB and intake for buildup
change the TPS

When does it ping? Load, hills, highway, city.....?

 

[xplordakota]

Originally posted by ton_e_montana
from what I've read, the larger throttle bodies for the OHV's that you get aftermarket are the same as the stock ones in the SOHC.

So just curious....Is it possible to take a SOHC Tb and put it on a OHV??

 

[Nate1]

Dirty fuel filter? Dying injector? What if you paid a shop about $80 to diagnose the real problem? You would probably have saved money by doing that a while ago...

 

[dmasini]

I changed the plugs and wires out last weekend and it doesn't ping as much now but still does it. Fuel Filter was changed less than a year ago... the fuel injector itself seems to be fine. I haven't had any troubled starts or smell any fuel. I took it to a dealership awhile back when it started doing it heavily and they said it could be a number of things and would have to "pull the engine" to find out specifically what the problem was. All I saw when he said that was $$$$ so I told him thanks for his time and left. I'll let this engine freeze up and then just buy another before I spend that much money to "diagnose" a problem.

 

[Alec]

You still haven't helped me diagnose your problem. When does it ping the worst?

 

[dmasini]

It starts pinging after the engine heats up to running temp. Then it will ping at idle and first through 4th gears the worst (all through 2000 to around 3500 rpm). Once I'm in OD a driving at a normal speed I really don't hear it at all.

 

[Bill Kemp]

Could a carbon builb-up cause the pinging? If so would sea foam or the Ford product for cumbustion chamber cleaning correct this?
Something cheap to try anyway....