Zealot

Hope the pictures post right.


Heres how to adjust MAF.

The MAF is the little silver box above the air filter. 1st step is to remove black cover


I used a sharpie and mark the dial, the little black dot at stock setting (very important!) I used the spring and the bottom of the dial as a point of reference. Adjust the dial clockwise to lean out and counter clockwise to enrich.

Zealot

WOOHOO! Hope this helps y'all.

Elton

nice but its not a maf sensor its called a VAFM

Zealot

ok, cool. Always called it that, never had anybody tell me different.

ovrrdrive

I found it easier to mark the little pointer that holds the wheel...



I posted a bunch of pictures about a year ago of it all. No one really seemed to care then either.

yoda84

ok i got a question what do i turn?

yoda84

is he turning the sprocket looking thing to make the coil looking spring tighter or looser......

seanmearse

This might be a dumb question, but why do this? I mean if you have headers, custom intake, things of that nature, i understand. But what would be the cause to make this adjustment on a stock engine? What benefits are there? What are the cons?

yoda84

cause y is a crooked letter..... na jus jok, i read it could better my idle cause i put in a different MAF and think it needs adjusting it idled fine before the exchange so i figure give it a shot.....but still what do i adjust.....

seanmearse

So, if i have not replaced my unit, it shouldn't need adjusting, right? Basically, would it be beneficial to do this, or a waste of my time? The 'Runner is pretty much stock, K&N air, Turbo II muffler, no major engine mods.

yoda84

well its probably worth a shot if you have a bad idle and tried everything else..

seanmearse

i do have an idle issue, but only when the a/c is on, i believe its the dashpot not raising the idle back up. no biggie, just goes from about 800 rpm's to about 600-650 rpm's.

phildelfino

Can you repost the pics in this thread, or do a video?

iamsuperbleeder

Very nice


adjusting the AFM is what first bought me to YT many moons ago



I might also add that it doesn't take a whole lot of adjusting to make a noticable change; start off with one, maybe two clicks at a time, and see how it goes

don't forget to reset the ECU after the adjustment each time by pulling the EFI fuse for about a minute



that sounds like a problem in the AC idle-up system to me...

bugs1961

The dashpot has no affect on the idle speed at all. It just slows the return to idle when the throttle is released. The A/C causes a drag on the engine that is compensated for by a vacuum switching valve (VSV) located on the right fender. It is the forward most VSV and has two regular vacuum hoses controlling the valve and two larger air hoses that allow extra air into the intake plenum when the A/C is turned on. If your idle decreases when the a/c is turned on, check the vacuum line connections first (as shown on the under hood sticker), and then check the VSV as shown in the FSM A/C section. Either the vacuum hoses are not connected properly or the VSV has failed.

Bugs

seanmearse

already checked. There is two vacuum adjusted deals on the throttle body linkage, the lower most one, located just above the valve cover is only working a little, when you turn on the a/c it only hisses, doesnt push at all, in the computer system at work it is described as the dashpot, and, according to picture its the part that is needed.

bugs1961

I'm not sure what vacuum operated devices are on your throttle body. A picture of what you're talking about would help. My 89' 3.0 doesn't have any vacuum operated equipment on the throttle body. Here is a picture of mine: the red arrow points to the dashpot, the blue arrow to the TPS, the yellow arrows point to the EGR vacuum hoses, and the purple arrow points to the EVAP vacuum hose.

As I described in the post above, my dashpot is not related to the A/C idle up and has no vacuum or electrical connections. It just slows down the return to idle to prevent too high intake manifold vacuum when the throttle is quickly released; thereby reducing emissions.

Take care,
Bugs

seanmearse

Yeah, the red arrow. It doesnt move at all when the throttle is revved and released, however, other than the idle when the compressor (a/c) engages it runs perfect, no hesitation, no sputter, no nothing. it doesnt make sense that it would slow down the return to idle, as it is a straight rod, while the linkage rotates at a constant circle, essentially, it would be a linear dashpot, correct? I think i am looking to far into something that has such a simple operation.

bugs1961

The rod in the dashpot is supposed to get pushed out a quarter inch or so by a spring but the rod gets dirty or corroded and sticks. You might be able to free it up with some silicone spray on the rod. Manually hold the throttle open and try to pull the rod out so you can spray it. I'll bet nearly everyone's dashpot isn't working after 15 or 20 years unless they've been worked on. The throttle cable assembly has a small tab that contacts the dashpot rod when closed but moves away from the rod when the throttle is opened.

The rod is connected to the front of a diaphragm inside the housing. The back side of the dashpot has a chamber to hold air and a spring to push the diaphragm and rod out when the throttle opens. The back of the housing has a cap you can take off. Under the cap is a small hole that lets air into or out of the chamber slowly. This is how the dashpot is supposed to control the return to idle. The rod is supposed to extend out while the throttle is open and when the throttle closes, it hits the rod, pushing the rod in. Because the air can only escape through the small hole, the rod is pushed in slowly.

The good news is that it really isn't a big deal if the dashpot doesn't work and I wouldn't spend money replacing it.

The bad news is that the air conditioning idle up isn't working. Look behind the battery on the right side inner fender and you'll see three vacuum switching valves. The forward one has a vacuum hose and two air hoses going to it. When you turn on the A/C, the VSV is electrically opened, allowing vacuum to pull on the diaphragm. The diaphragm controls a valve that allows air to go from the air cleaner (through a combination of hoses and pipes) into the intake manifold, increasing the idle speed.

The FSM that can be downloaded here http://www.ncttora.com/fsm/index.html has an A/C section that has a troubleshooting section that will determine what the problem is. Most likely, it is a vacuum hose that is blocked or disconnected but the FSM will walk you through it. Good luck and take care,
Bugs

seanmearse

thanks bugs. I will check it out my next day off.