Page 3 of 4 FirstFirst 1234 LastLast
Results 41 to 60 of 72

Thread: Idle adjustment question

  1. #41
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    Been getting up to speed on all this, fascinating!

    Some good YouTube on the AFM subject as well. Thanks for the link

    As for the AFM and its adjustment. I noticed the cog gear when I had it open. It looks like there is a spring with two legs spread eagle that spans the cog holding it down. Is there not some locking mechanism that holds the cog in place when adjusted? If so, then I would have to unlock it to move the cog.

    Again, it was hard to see from that angle.

    I will check the hoses on the way in today after she starts racing.

    I know where all the VSV's are:
    One for AC
    One for EGR (the one that people always break)
    One for super high temp to prevent vapor lock
    One that I have no clue what it does. It does work but for what reason I have no clue.

    All of these are new within the last year with new hoses so it will be easy to do this test.

    The only one with big hoses is the cold start bypass air valve that has a long tube and diaphragm and it is mounted under the intake manifold. Again, these all have new hoses so no problem doing the test.

    Thanks for more of this great info VanCo.

    Will keep it updated.

    MT

  2. #42
    Van Enthusiast VanCo's Avatar
    My Van(s):
    1987 Toyota Van LE 4x4 5spd, on 30x9.50R15s, boosted to 10PSI
    Join Date
    Mar 2017
    Location
    Salt Lake City
    Posts
    167
    Rep Power
    1

    Re: Idle adjustment question

    Sure thing!

    The large hose I was referring to is the one connected to the AC idle up diaphragm. You can actually pinch the line coming from the intake boot that feeds the diaphragm. That way you can eliminate the power steering pressure valve too. Another thing you can do is short the diagnostic connector (used for checking codes) while it's doing the high idle thing. When in diagnostic mode the ECU can only activate one VSV, the one that bumps RPM up by 100 (by the air box). All other VSVs are deactivated. If you go into diagnostic mode and the idle falls you know you have a vacuum routing/switching problem. If you can't get the idle to fall by pinching lines, or going into diagnostic mode, you may have a vacuum leak to atmosphere.

    In my opinion (if no leaks to atmosphere and the cold start valve isn't malfunctioning) the AC idle up diaphragm, and power steering pressure switch are the only things that can cause a single internal "leak" large enough to raise the RPM a few hundred revs.

    In the AFM the retainer is all that locks it down. To adjust it you pry one side of the retainer out, and with a flat screwdriver pry the gear to spin it. Then push the retainer back down. Some people remove the retainer with the screw, but that has the potential to cause chaos, especially if nothing is marked.

  3. #43
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    Very good, I got the plan. I will solve the fast idle first, then hit the AFM.

    Great input. Man it is great to know everything you are saying about all the VSV's. I know all of them by heart!

    Will let you know. I am sure this will do it.

    MT

  4. #44
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    And the Saga continues:

    Made some progress

    Replaced temp sender and O2 sensor. Clear ECU and all is well with no check engine any more.

    Started the van from cold, raced at 1200 then went a tad higher when the fan clutch engaged and slowly went down to 1100. All OK there.

    Now things begin to go south.

    Idle drops quickly to 600. then down to 400 shaking badly. Got in, popped it into drive before she dies and drove to work. I get to work and while in drive it is at 1000 and in park it went to 1500 and stayed there.

    Pinched all the are hoses as per your input. This made no difference with the RPM at all.

    Then I jumped the check engine connector and the RPM's dropped about 100 RPM. Maybe less than that. It was very little, so small it was hard to see on the vans tach.

    So I wonder if I am looking at this backwards. Maybe I should have set the idle when it is at its highest point at 20 minutes. Only problem there is the 500 RPM differential. If it drops 500 from there the engine will most likely die. Not sure but I could try that.

    This is working it the other way putting most of my efforts getting the idle up rather than trying to take it down. This may be a waste of time, not sure.

    So at the end of the day she is still racing.

    I am not sure what is left that would cause it to rise to 1500, have a 500 RPM change from drive to park after 20 minutes of drive time.

    It only takes 5 minutes or so for it to level off to operating temp on its internal temp gauge.

    I am thinking it has to temperature related but not necessary with the water temp but the ambient temp in the engine compartment. I did leave it running with the seat up and open and after about 5 minutes she was down to 1100.

    Now matter what way I cut it she still shakes when below 600 or 700 rpm no matter what.

    Any other thoughts? What else can raise the idle?

    I am still on the non ethanol fuel.

    MT

  5. #45
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    5,911
    Rep Power
    10

    Re: Idle adjustment question

    I feel your pain MT, and you certainly have more patience than I do. As much as I appreciate your desire analyze and find the exact cause, when it comes to my life, I personally simply don't have time or the patience for that approach. When I get to a certain point, I will usually resort the the "part changing mentality". I know it's cheating and not the proper way, but considering all the parts I have available and the time saving aspect it's a "no brainer". I also justify it by telling myself it's an antique vehicle with diminishing availability for parts, so I make sure to always have at least one known good extra part for everything stashed away. If you have room, and can find a parts van, that can make your life much easier.

    If I were having your issue, and I'd already exhausted the easy to check/verify issues, I'd start swapping out parts. You've done the Air Valve and the ECU, so that leaves the AFM, igniter, and distributor w/coil. I'm guessing your problem will be remedied in swapping one of those parts, but if it's not, at least you can rule these things out and move your attention to other areas. If/when you have an eventual failure, you'll already have the spare parts and you'll not be forced to search and pay top price due to an emergency "van-down" situation.

    Of course I don't know your situation, so my way may not be right for you. If tinkering is something you enjoy and you have an extra vehicle, + the time/patience, then your current approach could be the right way or even the best way for you. You are certainly obtaining a more intricate knowledge of the inner workings of these components, so if education is your goal, then this is also a good way to learn. Tim

  6. #46
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    Appreciate your words of wisdom Tim.

    My passion in getting it right is brought on by one thing.

    Sure, I could go out and buy any vehicle I please. This is not the issue.
    It was time to replace my vehicle and as much as I looked around I found nothing that made me happy.
    That is when the wife steps in. Finally after checking out all the crap out there, mostly SUV stuff, she finally put her foot down and said what would make you happy.

    That was easy, I wanted MyToy back!! I owned 2 of them back in the day and had to let the last one go since it was part of the company I sold.

    But they canned the model and that was it.

    So I decided to search for one I could bring back and found this in Seattle
    Single owner and new his stuff. He took uber care of her and she sat for 25 years.

    What many of you may not have what I have and that is AGE!!!

    I had 2 new vans in my life and they were the best thing since sliced bread. I know what they are and I know what they can do. I don't expect it to be new again, but I do expect it to be somewhat what I had. Even with all the stuff I have done on her and left to be done, I love driving her. It's great and besides this idle problem there are others primarily due to the idiots I had do the work on her. I basically had too repaired all they screwed up one at a time on my own and this group of people.

    Then you have to consider the group i.e. TVT. It is a great bunch of people that own these beauties and they will all at some point in time have the same issues all of us have had.

    I think I mentioned that I am also a pilot and own a vintage airplane. Much older than the van, a true classic. We have 230 in the fleet left with over 200 that went down. So all of us are trying to keep the fleet alive, and alive it is. There are no parts except if you can find one in salvage and that is 100 times rarer than our vans.
    The beauty about pilots and airplane enthusiast is they all have their talents from machine work to airframe fabrication. So everyone helps each other out and we pretty much have re-created the factory for the aircraft. And flying her is just as great as driving MyToy.

    I have a 1974 Porsche 911. Bought it new and today it is still in mint condition and always can be fix.

    Here are some pics of these.

    My point is I know that MyToy can come back and I aim to get there without spending stupid money. Did it with the plane and did it with the 911.

    Show them the way and they will come.
    Attached Images Attached Images     

  7. #47
    Administrator timsrv's Avatar
    My Van(s):
    Lots of them
    Join Date
    Jun 2010
    Location
    SW WA ST
    Posts
    5,911
    Rep Power
    10

    Re: Idle adjustment question

    I thought the Jodel F-11's were all tail draggers. That's a nice set-up! Van and Porsche are beautiful too! Keep at it and you'll get it figured out. I have no doubt . Tim

    Oops, I see it's a Rockwell Commander, never mind
    Last edited by timsrv; 12-20-2019 at 02:00 AM.

  8. #48
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    The plane was actually built by Gulf Stream and was called an Aro-Commander. Rockwell designed her and name her an AC-11.
    She has been modified a bit with the 3 Bladed Scimitar Prop and an after market turbo. She will cruise at about 160 MPH at 12,000 feet. The world becomes a smaller place when you have a plane.

    Last nights ride home from the office the RPM's went to 1800 in park at idle. It has to be something drastic.

    Mt

  9. #49
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    One more thing, I believe even if I were to bring the high idle down to some reasonable number the idlescrew would bottom out by then. I will check that this morning when I get to the office.

    VanCo was right though. The only thing in the system big enough to make that much of an idle change is either the AC or the cold start Air Bypass, but the pinch test proved those are OK.

    What I have not considered was the Mass Flow unit. I am wondering if I could manually reduce the idle by manually turning the wiper in there. It clearly is not a fix but it may give me a hint if it were the mass air flow unit. I can pick up a re-manufactured one from Carid. The show they have one but would rather have a better feeling it could be the culprit. May have to buy it and hope.

    I can't see the igniter or the distributor being high on the suspect list for this idle issue.
    I also thought it could be something on the air mixture control allowing air to be sucked in from atmosphere when it or a portion of it gets warm. That would be easy, I could just freeze the SOB with a couple of freeze spay cans. It would take a lot but maybe worth it.

    Will keep you posted.

    MT

  10. #50
    Van Enthusiast VanCo's Avatar
    My Van(s):
    1987 Toyota Van LE 4x4 5spd, on 30x9.50R15s, boosted to 10PSI
    Join Date
    Mar 2017
    Location
    Salt Lake City
    Posts
    167
    Rep Power
    1

    Re: Idle adjustment question

    The RPM drop going from 1500 RPM to drive will be different than going from 1000 RPM to drive, due to the load on the torque converter, and how engaged it is. It is not a linear relationship. The more RPM the more engaged the torque converter will be once it's loaded by putting it in gear. This means less RPM drop at low RPM, and more RPM drop at high RPM.

    Speaking of, how does the transmission shift? How is the fluid? Does the torque converter feel too tight when it's cold and you're driving? Does it ever stall when coming to a stop (like it would if you had a clutch and didn't push it)?
    Last edited by VanCo; 12-20-2019 at 08:06 PM.

  11. #51
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    Hey VanCo:

    Transmission has really been fine.It had a leak and was fixed plus the round plastic balls were replaced.

    It never stalls so long I have the idle high enough. Again, once she gets down to under say 700 to 900 she shakes real bad. Once over 1K she smooths out. So when I set the idle I generally set it when I see the water temp at 180. Then set it for 800. She shakes a little for sure. In drive she shakes much worse and the van moves with little jumps during between shakes. Then after 20 minutes on the highway I can come off an exit to stop and she is at about 950, put her in park and she climbs to 1600.

    I really think the transmission is OK.

    I did do a test reducing the idle after she got up high yesterday. This time it was about 1600 rpm. So I stuck my screw drive in the hole and turned it until she came down to 800. The screw bottomed out and it started shaking again. So the shake is there no matter. When hot and in drive with brake on she idles at about 900 with a small shake. So I can drive here all right but man if I shut her off or put in park getting her back in drive is like I launch off the ground like the picture of your van here in your ID.

    Suppose to rain like hell tomorrow, so I will plan on some time to see if I can find why it is so high.

    Next week I plan on bringing her over to a muffle shop to have the O2 fitting installed also.
    By the way I found this 5 wire. Unlikely I would permanently install. Will only use it to get the van fix.

    5 wire O2 https://www.amazon.com/Wideband-Oxyg...23620285&psc=1

    Just have to find a gauge

    MT

  12. #52
    Van Enthusiast VanCo's Avatar
    My Van(s):
    1987 Toyota Van LE 4x4 5spd, on 30x9.50R15s, boosted to 10PSI
    Join Date
    Mar 2017
    Location
    Salt Lake City
    Posts
    167
    Rep Power
    1

    Re: Idle adjustment question

    I've only bought the wideband O2s as a kit with everything needed. The components are sold separately though. Just make sure you get the right gauge controller to match that LSU 4.9 sensor.

    The air temperature in the AFM will be affected by heat soak in the engine compartment. It'll give a different reading during warmup without driving, and driving for a while (normal due to temp change). If the sensor is bad it could be giving the ECU an erroneous value once warmed up. Just an idea.

  13. #53
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    You mean the Temp sensor in the AFM?

    I would have thought that since it is in the air flow channel inside the AFM the incoming air would keep it at close to ambient temp. If I am not successful with leak tests and freeze tests I may just order the rebuilt one.

    Thanks

    MT

  14. #54
    Van Enthusiast VanCo's Avatar
    My Van(s):
    1987 Toyota Van LE 4x4 5spd, on 30x9.50R15s, boosted to 10PSI
    Join Date
    Mar 2017
    Location
    Salt Lake City
    Posts
    167
    Rep Power
    1

    Re: Idle adjustment question

    Yes the air temperature sensor in the AFM. For the most part the air temp will be close to ambient, however; that will change the longer you drive and the more the engine compartment, AFM, and airbox become heat soaked.

  15. #55
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    Interesting for sure. I did make some progress yesterday. I tried the butane approach sniffing out the leak but I felt I really needed to give it some rocket fuel. So I used starter fluid this time. Being very careful I shot each air hose one at a time. I also shot the entire mixture control units seams and bold, and the entire air connection to the AFM.

    I found on the cold air bypass a 400 rpm increase when I shot the hose that goes into the steel tubing that goes up to the intake manifold. I chopped it back, used clamp and that stopped that leak. It did not drop the RPM at all and it still shakes a bit. But there is nothing else to check but for the AFM. If I buy a new one, it may solve this but still may be off the 14.7 ratio I am looking for. No way I would crack that one open and lose any kind of warranty.

    So I think over the holiday weekend I will remove the AFM and inspect it through and through. Plus I can see better what I will have to do when I adjust the mixture. That Temp sensor inside I could also test to see how it response with difference heat conditions.

    Keep plowing forward

    MT

  16. #56
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    More updates on this.

    I found one time I shut the engine off I heard a small little poof somewhere on the top side of the engine.

    Close examination I found one of the rubber washers used for the valve cover acorn nuts had melted and was almost sucked into the valves. This produced an area around the stud that was not sealed. So I replaced with a new rubber washer and the poof went away. Along with that the shakes reduced by better than 50%. I tested the theory by removing the oil cap and the same thing re-occured. This is part of the EGR system and had an effect on the idle.

    Now I am down to about 800 RPM with almost no shaking when up to full operation temp.
    Although when cold and after the cold start air bypass closes the idle goes down and it begins to shake again, but not as bad as before. Still causes the van to jump intermittently when put in gear. Give it 5 minutes of run time the shaking just about goes away.
    I then monitored the voltage drop across the Temp sensor to see if that number was in line with the cold start shake. When cold it is about 2 volts. At full operating temp it drops to about .43 volts DC.

    So I thought maybe this was a bit off on timing and voltage so I induced a change with an additional potentiometer so I could manually reduce the voltage on my own.

    This proved unsuccessful. It made no difference.

    So now I am down to a near stall just after the cold start air bypass turns off.

    I am sure I am being super anal on this but I am so close of having it perfect I will continue to seek out more issues.

    I will have the O2 sensor installed now just to see how that looks now with it running the best since I rebuilt the engine.

    But she is really nice at full temp with an RPM at 600 in drive.

    What still puzzles me is the more often then not a hard shift into gear even at 800 RPM idle. This may be still another issue with a transmission issue.

    It is real nice to drive at 80+ MPH and come to a stop and she hangs right in there at 600 RPM without the tach jumping from the previous shaking issue.

    Will keep the updates coming in as I move forward on the O2

    MT

  17. #57
    Van Obsessed
    My Van(s):
    1988 4WD LE auto dual range t-case (the mistress) 1988 4WD LE auto(the donut van)
    Join Date
    Aug 2012
    Location
    Tacoma, Wa
    Posts
    590
    Rep Power
    1

    Re: Idle adjustment question

    Sometimes in our diagnostic quests we overcomplicate things. I am frequently guilty of this myself. You had a vacuum leak. Not where you would expect it but a vacuum leak nonetheless. I had started to suggest this awhile back but never posted it. You had sprayed all your vacuum lines and intake gaskets more than once with no success so I never mentioned it. It sounded too simple but my gut kept telling me vacuum leak. You introduced air behind the throttle plate that the idle circuit in the computer couldn't regulate. The signal from the oxygen sensor indicated a lean condition so the computer added fuel to correct it which increased the idle.

  18. #58
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    Yep, sure wish that gut feeling go through, would maybe have saved me some time. VanCo was a big help also providing me all the other alternatives.

    More test runs today with consistence results. So it is not changing its operation much at all now except for the idle differential of 300rpms and the shakes when cold start up. Have to feather the gas when stopped during this time period, again only 5 min or so.
    In your opinion, is 300 within tolerance for this vehicle or should it be better?

    I think if I find this small issue it will correct both the differential 300 rpm and the shaking as well.


    This all may come out with the O2 numbers also.

    We shall see.

    MT

  19. #59
    Van Obsessed
    My Van(s):
    88 4WD DLX 5spd
    Join Date
    Oct 2010
    Location
    Ontario, Canada
    Posts
    833
    Rep Power
    1

    Re: Idle adjustment question

    MT - did you replace just the one melted grommet/washer?

    If one was compromised, there is no reason to suspect the rest are still good
    The fact the idle smooths out once fully warmed would make me think there are more (small) leaks that abate once the rubber expands with heat

    As far as it clunking into drive, have you checked motor mounts and U-joints (recently)?
    Mounts can separate, allowing the engine to flop around some.
    With compressed mounts, the engine sits lower in the chassis and can cause clearance issues resulting in vibrations being transmitted into the chassis.

    When I replaced mine, it was one of THE most rewarding repairs as it solved several issues, all at once.

  20. #60
    Van Enthusiast
    My Van(s):
    1986 LE
    Join Date
    Aug 2017
    Location
    Florida
    Posts
    258
    Rep Power
    1

    Re: Idle adjustment question

    Great Points!!

    Both motor mounts and drive shaft have been replaced.

    I did check the other 2 rubber seals and they are fine.

    I may go back and shoot all of them again to see if I missed one.

    Transmission does not clunk when first setting to drive however after I am use the van for a while it will clunk event when at 800RPM.

    So another strange issue.

    Thanks for the suggestions

    MT

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •