Jump to content

If you receive an influx of emails from the forum, please disregard as they are cached.  Our email provider changed server settings without notifying us.  The new settings have been applied so normal mailings should resume, per system settings and user preferences.  This includes new account signup validation emails. - Updated: 06/11/2022 2:48PM PST

_______________________________________________________

Due to a hardware failure on the hosts systems, all posts and messages created between May 26th and Jan 13th have been lost. Additionally, if you joined the NPORA Forums community during that time, you'll need to re-register. -NPORA Mod Team *Updated: 05/19/2022 12:15AM PST

Throttle Body screw/Adjustment


Recommended Posts

for starters find my TBI thread in the pinned section, it will explain allot.

if its not there take a picture and I will figure it out by examining and testing my spare parts.

Edited by MY1PATH
Link to comment
Share on other sites

I beleive I was told before about this screw being some sort of mixture adjustment but I am not sure. I would like to know what it is though. If somebody else is able to locate it maybe they could tell me the number of turns in I should be at.

 

Who is gonna mess with theirs first to see what it does?

Link to comment
Share on other sites

:crossedwires:

 

I had it turned in about 3 turns, which is about halfway, then i turned in out about 1 1/2 turns, so its about 1 1/2 turns from flush with outside of housing. I did notice smoother preformance at higher rpms and truck seemed to gain alittle power. It could be my imagination though. Wish I had an exhaust gas analyzer to test at idle.

Edited by 1988pathfinderoffroad
Link to comment
Share on other sites

never noticed it either. But, based on where it is and where it's pointing, I'd say it a stop adjust for the butterfly valve. And yes, tomorrow is my day off and I'm gonna go and see what is does.

 

Also, I'd replace that stainless steel nut (the red one) with regular zinc coated steel before that rust gets worse. Ever see a rusted out bbq burner? that is how it happens; stainless an aluminum= bad news

Edited by LittleReD89
Link to comment
Share on other sites

If it is a mixture adjustment. I think turning it out richens the mixture. I took truck on interstate this morning was cruising easy at 75, but noticed the drivers side floorboard alittle warm. I'm thinking richer mixture and exhaust gets hotter. I know the exhaust pipe runs right under driver floorboard.

Link to comment
Share on other sites

I've never seen that before, I really want to know what that is. If it's a manual air/fuel mixture adjustment I'm willing to bet it'll sove quite a few of my problems.

 

If I'm not mistaken the person who told me about this screw said it might be covered by a factory plug.

Link to comment
Share on other sites

I adjusted mine, and either it's just me or it doesn't smell as rich at idle. :shrug:

i wonder if mine needs adjusted.. Just a LITTLE... i smell gas when i first start it and when i just let it sit running for a while.

Edited by SexJelly
Link to comment
Share on other sites

i wonder if mine needs adjusted.. Just a LITTLE... i smell gas when i first start it and when i just let it sit running for a while.

 

:stickwack: Yours is MPFI and completely different.

Link to comment
Share on other sites

I adjusted mine out, to the left. I would assume that would allow more air into the mixture and it seems to have more power and isn't sucking as much fuel. :shrug:

 

Thats what I'm thinking also. I guess floorboard was just getting hot because it wasn't used to cruising at 75 on interstate. When I adjusted mine out it didn't smell as bad either.

So I guess it wasn't just my imagination, because it definitely seemed to cruise on the Interstate alot better.

Link to comment
Share on other sites

to the left or counterclockwise will lean the fuel mix clockwise will richen the mix do not do any adjustments until the engine is up too full temp 10 min at least and turn a half a turn at a time to smooth out your idle

 

and yes it is your imagination it will not affect mid or top end power or acceleration

Edited by madhornet
Link to comment
Share on other sites

to the left or counterclockwise will lean the fuel mix clockwise will richen the mix do not do any adjustments until the engine is up too full temp 10 min at least and turn a half a turn at a time to smooth out your idle

 

and yes it is your imagination it will not affect mid or top end power or acceleration

 

I definitley noticed more top end power and that is probably where you would see it. I doubt you'd notice any power at mid or low RPM's. The Oxygen sensor would normally take control of the mixture, but accelerating and higher RPMS the oxygen sensor does not function, it would rely on base mixture settings. My truck never cruised at 75 like it did before the mixture adjustment. So the only place you would see benefits from the base mixture adjusment would be under heavy loads and at idle.

Link to comment
Share on other sites

I definitley noticed more top end power and that is probably where you would see it. I doubt you'd notice any power at mid or low RPM's. The Oxygen sensor would normally take control of the mixture, but accelerating and higher RPMS the oxygen sensor does not function, it would rely on base mixture settings. My truck never cruised at 75 like it did before the mixture adjustment. So the only place you would see benefits from the base mixture adjusment would be under heavy loads and at idle.

 

 

thats, backwards the engine is run by the o2 sensor once you exeed 2800rpm.

Link to comment
Share on other sites

I noticed a little bit of a side effect. Highway mileage is terrible, and I'm thinking it's because I leaned it out so much that the O2 sensor is overcompensating for it. I went somewhere, all highway, that usually takes 1/8th to at most 1/4 tank. I used almost a half. :thumbsdown:

 

But it does not smell nearly as rich at idle and it doesn't bog down like it used to. So now I know I have a way-too-rich fuel mixture somehow, and I need to fix it instead of doing this...

Link to comment
Share on other sites

thats, backwards the engine is run by the o2 sensor once you exeed 2800rpm.

 

The engine uses the oxygen sensor at cruising speed once the idle/switch is off and the engine is at normal operating temperature and the oxygen sensor is warmed up. You can veryify this easily by probing the O2 sensor signal voltage or putting your ECU in diagnostic mode 2, putting your passenger seat forward and having someone ride around with you in the backseat while they watch the LED's You will see them flash once the idle switch is off and they will notice more blinking at cruising speeds, the truck will go into open loop, if the mixture gets too rich

Edited by 1988pathfinderoffroad
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

Welcome to NPORA Forums

 

Please register to gain full access to the forum.

Make sure you read the Forum Guidelines and don't forget to post a new intro in the New People Start Here! section, to say hi too everyone.

 

-NPORA

×
×
  • Create New...