Jump to content
Josh_Path2346

VG30i Throttle Body adjustments

Recommended Posts

Ive recently rebuilt my throttle body and I need to know how to readjust it. I was also wondering where I might be able to find a new Idle Up solenoid. If anyone could help me out Id greatly appreciate it. My specs are below

 

1989 Pathfinder

3.0 V6 VG30i

4x4

Automatic 

Share this post


Link to post
Share on other sites

Didn't know there was any adjustments possible with the TBI other than the base idle speed. 

Share this post


Link to post
Share on other sites
15 hours ago, Josh_Path2346 said:

Ive recently rebuilt my throttle body and I need to know how to readjust it. I was also wondering where I might be able to find a new Idle Up solenoid. If anyone could help me out Id greatly appreciate it. My specs are below

 

1989 Pathfinder

3.0 V6 VG30i

4x4

Automatic 

Two screws on the throttle body. One is horizontal and controls the base idle, you can adjust it easily with the truck running.  There is also the fast idle screw, It points upwards at an angle and controls the idle speed before the truck is warmed up.  You have to push a screw driver into it hard enough that it opens the butterfly valve pretty wide to get it to turn, otherwise you can't get the screw driver on it without removing the air filter housing because the angle it points at with the throttle body valve closed. Adjust it with the truck cold and off, then start the truck and see if it's where you want it. Rinse and repeat till satisfied. I have mine set around 1100 cold and 800 warm.

Share this post


Link to post
Share on other sites

Ive gotten it to finally start up again but now its surging when in park. The RPMs will go up and down endlessly while its sitting there. Fresh gas and everything too. When I turn it off, thin white smoke comes from around the throttle body. I have no idea what to do

Share this post


Link to post
Share on other sites

There's some good info here, though of course the pictures are screwed up because Photobucket (apparently there's a browser extension that'll get you past that). Can you see where the smoke is coming from? Could just be oil and crap burning off, doesn't seem like the TB should be getting that hot though unless the mixture heater's kicking on for some reason or the smoke is drifting up from somewhere else. Does it also surge in gear? Does it clear up off-idle (revving it or driving)?

 

I had a look at the '89 manual. For an unstable cold idle, it suggests checking the ignition timing, the fast idle cam, the fuel regulator, the idle speed control valve, the EGR valve, the EGR solenoid, and then run codes, in that order; if that doesn't do it, unplug the cylinder head temp sensor and see if that changes anything. For an unstable warm idle, it suggests checking for vacuum leaks in the PCV system, the intake, and the vac lines, checking spark quality/plug condition/plug wires (I assume more for a misfire condition than for surging), timing, compression, and EGR. I would also check the electrical connections on the throttle body to make sure they plug in securely and the pins are clean and not oxidized. If a plug seems suspect, wiggle it with the engine running and see if the idle responds.

 

If you want a PDF of the '89 service manual, let me know and I'll try and remember how I got it to the last guy.

Share this post


Link to post
Share on other sites

Please, Id really appreciate a service manual. Right now its sitting in the driveway because it wont even run anymore. I cant tell you how much I need it up and running again

Share this post


Link to post
Share on other sites

PM'd. Hopefully Dropbox plays nice. Good luck!

Share this post


Link to post
Share on other sites

The dropbox link didnt work, unfortunately. Can you email or send me a link?

Share this post


Link to post
Share on other sites

Figures. PM me your email address and I'll see if I can get it to you that way.

Share this post


Link to post
Share on other sites
Posted (edited)

Never mind, I got it to work finally. What would timing do to effect the idle surging up and down? I'm sure the EGR and its solenoid work because I cleaned them out by hand. I've checked all my vaccum lines and there's nothing to suspect of them. Its not a fuel problem either, as for the first 10 seconds it runs (rpm at or around 3000) and then it drops idle (1500 rpm) and starts surging. Should I mess with the timing? I know there's no ignition problem, as I just replaced the plus and they all seek to work. I've never let it warm all the way up either, as I'm too scared to let it blow up

Edited by Josh_Path2346
Needed more information

Share this post


Link to post
Share on other sites
Posted (edited)

Might sound stupid, but have you reset your ECU? I cleaned off my MAF recently and had the same surging while at idle afterwards (this was NOT an issue before cleaning MAF) - checked all vacuum lines, checked EGR, AIV, etc. Turns out the problem righted itself when I unplugged the battery for a few minutes and let the ECU reset itself. 

 

Idles perfectly now and I think the A/F ratio is way better as a result as it smells way less of gas. We'll see if mileage improves after I fill up.

Edited by Hanks88

Share this post


Link to post
Share on other sites

Itll be sitting for a while with no power so I dont think its the ECU

Share this post


Link to post
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

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...