'92 3.0 dies after throttle release....
02-01-2008, 02:35 PM
#21
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Yes and yes. Why? What'd you do?
02-01-2008, 05:55 PM
#22
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My 4runner has the same exact problem.
Thook-
I was going to offer the wiring harness off my salvage yard motor but then I read on and saw that you found out it was not you soldering job.
So the problem is in fact the DashPot correct? Thanks
Thook-
I was going to offer the wiring harness off my salvage yard motor but then I read on and saw that you found out it was not you soldering job.
So the problem is in fact the DashPot correct? Thanks
02-01-2008, 08:21 PM
#23
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Nothing I just noticed that mine is just about never in contact with my butterfly linkage unless its at idle other than that it is not in contact. Which means that it cant idle which would also cause an over rich condition......Just thinking out loud here dont mind me. I think that I screwed up mine what i blew out my intake manifold with shop air when I did my engine swap.
thoughts....?
thoughts....?
02-02-2008, 08:56 AM
#24
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Yep....that's all it was. It's running like a champ now.
Nothing I just noticed that mine is just about never in contact with my butterfly linkage unless its at idle other than that it is not in contact. Which means that it cant idle which would also cause an over rich condition......Just thinking out loud here dont mind me. I think that I screwed up mine what i blew out my intake manifold with shop air when I did my engine swap.
thoughts....?
thoughts....?
The dashpot and throttle lever should only come in contact when the throttle is released and when the vehicle is at idle. In that case, it should always be in contact. The dashpot will not affect your idle in anyway other than directly relating to throttle release. If the vehicle won't idle correctly.... when the throttle is at rest as opposed to blipping it.....you've got another problem. You see, my vehicle was idling fine UNTIL I blipped the throttle.
02-02-2008, 01:50 PM
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oooh ok now I see thanks for clearing it up for me.
Yeah I know your right in that I have another problem...currently the solution just eludes me. This afternoon I replaced my throttle body with one with out a dash pot. only the TPS configuration is different and not am running w/o one ....hahah switch one problem for another I guess. Thanks again thook
Yeah I know your right in that I have another problem...currently the solution just eludes me. This afternoon I replaced my throttle body with one with out a dash pot. only the TPS configuration is different and not am running w/o one ....hahah switch one problem for another I guess. Thanks again thook
02-02-2008, 02:34 PM
#26
The idle adjustment screw cavity, when screw is removed, collects blow-by gunk over time. I would remove the throttle body, take everything off, soak it in carburetor cleaner to remove the gunk in the passages. Works good for carburetor problems by cleaning all those little passages internally. If you don't want to do that, pull the brass adjustment screw and blast that passage with carburetor cleaner in the spray can. Helped mine quite a bit. Also, replace the little rubber O ring on the screw as they go flat over time and shrink.
My $0.02
My $0.02
02-02-2008, 04:21 PM
#27
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Maybe I should've titled this thread "Throttle Body 101"....lol.
I'm going to look at the o-ring myself. I didn't know there was one in there. Not that I'm having problems anymore, but it wouldn't hurt to check....I s'pose.
Something I discovered through all this tinkering is that the relationship between the TPS, throttle stop, and idle adjust screw and the idle speed itself has a wider threshold than I realized. In other words, you can adjust the idle screw all the way....which is where it currently is...and adjust the throttle stop further out to raise the idle in compensation. Then, you just have to adjust the TPS (namely the idle switch settings) and the DP (since the throttle stop setting is different) accordingly. I'm going to set everything back to it's factory settings for a few reasons I will illustrate below, but at the moment it's behaving normally.
The low voltage reading seems to be related to the setting of the throttle stop at the time I was testing.....according to the mechanic. Remember, I didn't have my feeler gauges handy, so I set it as best I could without. When I set everything back proper like....with the feeler guages...I'm going to check the VAM/VS reading again to see what I get.
Here's what Don Clark..the mechanic...had to say when I questioned him about the VS reading:
"The VS voltage reading is an indication of where the vane in the air flow meter is positioned. A lower reading would indicate a more closed flap, the reading would go higher as the flap or vane is opened as it is when more air is flowing past it. Even though the idle speed might be correct, the air available to enable this correct speed may be coming from the screw on top of the throttle body, rather than from around the throttle plate. Air around the throttle plate would be controlled by the hard idle stop screw, and would have a direct affect on the voltage readings from the VAF. I suspect if your idle speed and the dying problem is fixed, I'd leave things alone for now. However, the lower VAF reading would also affect injector pulse width, and might cause a lean idle condition. Again, if you have no obvious problems, things may be fine as is."
Scary story.....
Today my wife was driving the '92 and something went screwy. While cruising in overdrive the speedo and tach started climbing and dropping erratically for seemingly no reason at all. The transmission (think...."electronically controlled" transmission) had shifted down into first and would not recover to a proper gear for the speed travelling. Well, the ECM has been unbolted and carefully laid in the floor board ....throughout all of my replacment, cleaning, and testing....with a pillow to rest on. In all of her errand running, she'd laid the 18v rechargeable flashlight on top of it.
Can we say BIG MAGNET!!?
She didn't realize what she'd done. I think I'll mount that sucker back up, now! 
I'm going to look at the o-ring myself. I didn't know there was one in there. Not that I'm having problems anymore, but it wouldn't hurt to check....I s'pose.
Something I discovered through all this tinkering is that the relationship between the TPS, throttle stop, and idle adjust screw and the idle speed itself has a wider threshold than I realized. In other words, you can adjust the idle screw all the way....which is where it currently is...and adjust the throttle stop further out to raise the idle in compensation. Then, you just have to adjust the TPS (namely the idle switch settings) and the DP (since the throttle stop setting is different) accordingly. I'm going to set everything back to it's factory settings for a few reasons I will illustrate below, but at the moment it's behaving normally.
The low voltage reading seems to be related to the setting of the throttle stop at the time I was testing.....according to the mechanic. Remember, I didn't have my feeler gauges handy, so I set it as best I could without. When I set everything back proper like....with the feeler guages...I'm going to check the VAM/VS reading again to see what I get.
Here's what Don Clark..the mechanic...had to say when I questioned him about the VS reading:
"The VS voltage reading is an indication of where the vane in the air flow meter is positioned. A lower reading would indicate a more closed flap, the reading would go higher as the flap or vane is opened as it is when more air is flowing past it. Even though the idle speed might be correct, the air available to enable this correct speed may be coming from the screw on top of the throttle body, rather than from around the throttle plate. Air around the throttle plate would be controlled by the hard idle stop screw, and would have a direct affect on the voltage readings from the VAF. I suspect if your idle speed and the dying problem is fixed, I'd leave things alone for now. However, the lower VAF reading would also affect injector pulse width, and might cause a lean idle condition. Again, if you have no obvious problems, things may be fine as is."
Scary story.....
Today my wife was driving the '92 and something went screwy. While cruising in overdrive the speedo and tach started climbing and dropping erratically for seemingly no reason at all. The transmission (think...."electronically controlled" transmission) had shifted down into first and would not recover to a proper gear for the speed travelling. Well, the ECM has been unbolted and carefully laid in the floor board ....throughout all of my replacment, cleaning, and testing....with a pillow to rest on. In all of her errand running, she'd laid the 18v rechargeable flashlight on top of it.
Can we say BIG MAGNET!!? She didn't realize what she'd done. I think I'll mount that sucker back up, now!
02-03-2008, 07:44 AM
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so i unplugged the vacuum line going to the dashpot and covered it with my finger. idle seemed to clean up. does this mean i have a faulty dashpot? do you think silicone spray would fix it or should i replace it, as i have a spare. does replacement require tps readjustment?
02-03-2008, 12:24 PM
#29
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There's not a vacuum line going to the dashpot. It doesn't require vacuum from the engine to operate. I believe you've disconnected the line to the throttle opener.
02-03-2008, 07:29 PM
#31
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I guess we'll see...if he decides to post back.
Hey Gary! How's it han....I mean goin'?
The flashlight appears not to be the cause of the erratic behavior. The TPS is a lot more sensitive to the tinkering I've done than I'd realized. It seems the auto tranny is not happy with the TPS not being where it's supposed to be in relation to the throttle angle. I'm going to adjust everything back to the factory settings tomorrow and see if it clears things up. After I wrote about the flashlight thing, the vehicle started throwing a code 42 for the speed sensor circuit....TPS input being a part of that. I believe it's set too far out of range for the tranny to shift and hold gearing properly.
More tomorrow. It's movie time!!!! American Gangster, even. Whoohoo! (We'll see. I don't have put much stock in most Hollow-wood movies.)
Hey Gary! How's it han....I mean goin'?
The flashlight appears not to be the cause of the erratic behavior. The TPS is a lot more sensitive to the tinkering I've done than I'd realized. It seems the auto tranny is not happy with the TPS not being where it's supposed to be in relation to the throttle angle. I'm going to adjust everything back to the factory settings tomorrow and see if it clears things up. After I wrote about the flashlight thing, the vehicle started throwing a code 42 for the speed sensor circuit....TPS input being a part of that. I believe it's set too far out of range for the tranny to shift and hold gearing properly.
More tomorrow. It's movie time!!!! American Gangster, even. Whoohoo! (We'll see. I don't have put much stock in most Hollow-wood movies.)
02-04-2008, 10:00 AM
#32
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ok so ya i was wrong about what i disconnected. 
after closer inspection i actually located the dashpot and realized that the cap and filter element were missing all together. i put those on but problem still seems to persist although it does run better. if i let off the trottle fast idle falls below 600 but if i let off slow, it sits where it should at about 850. do you think the dashpot is still resposible for this
after closer inspection i actually located the dashpot and realized that the cap and filter element were missing all together. i put those on but problem still seems to persist although it does run better. if i let off the trottle fast idle falls below 600 but if i let off slow, it sits where it should at about 850. do you think the dashpot is still resposible for this
02-04-2008, 05:44 PM
#34
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Thread Starter
I guess we'll see...if he decides to post back.
Hey Gary! How's it han....I mean goin'?
The flashlight appears not to be the cause of the erratic behavior. The TPS is a lot more sensitive to the tinkering I've done than I'd realized. It seems the auto tranny is not happy with the TPS not being where it's supposed to be in relation to the throttle angle. I'm going to adjust everything back to the factory settings tomorrow and see if it clears things up. After I wrote about the flashlight thing, the vehicle started throwing a code 42 for the speed sensor circuit....TPS input being a part of that. I believe it's set too far out of range for the tranny to shift and hold gearing properly.
More tomorrow. It's movie time!!!! American Gangster, even. Whoohoo! (We'll see. I don't have put much stock in most Hollow-wood movies.)
Hey Gary! How's it han....I mean goin'?
The flashlight appears not to be the cause of the erratic behavior. The TPS is a lot more sensitive to the tinkering I've done than I'd realized. It seems the auto tranny is not happy with the TPS not being where it's supposed to be in relation to the throttle angle. I'm going to adjust everything back to the factory settings tomorrow and see if it clears things up. After I wrote about the flashlight thing, the vehicle started throwing a code 42 for the speed sensor circuit....TPS input being a part of that. I believe it's set too far out of range for the tranny to shift and hold gearing properly.
More tomorrow. It's movie time!!!! American Gangster, even. Whoohoo! (We'll see. I don't have put much stock in most Hollow-wood movies.)
Denzel got style!After clearly going everthing the '92 was doing with my wife, the TPS may only be a small part of the problem...if at all. I didn't have time today to mess with it. But, I went over the problems, talked to Don Clark, read a lot, and rethunk the gammut of symptoms.
There are two vehicle spd sensors on the auto tranny....A340H. One of them controls the speedo, trip meter, and odo and one controls something else. Don't know about that, yet. Still alot of studying to do. One...maybe both...are interconnected with input from the TPS and coolant temp sensor....the temp sensor not part of the problem I'm having.
Here's a full scale diagram of the entire circuitry:
http://personal.utulsa.edu/~nathan-b...34electron.pdf
I'm going to have to track down atleast TPS input and both spd sensors' input. There maybe something else wrong....like with a bad grounding or the used ECM I just put in, but since I've not had the chance to test anything nothing is being blamed, yet.
The ECT (electronically controlled transmission) has a built in diagnostic system and fail safe mode.
http://personal.utulsa.edu/~nathan-b...31diagnosi.pdf
If when the OD selector is ON and the light flashes, it works on the same principal as the CEL. You even jump the same terminals at the data link/diagnostic box. It will flash a code if their is problem UNLESS certain conditions are present (which I will leave those interested to read about in the links provided), but a code will still be in the ECM. My OD light flashes consistantly....indicating no problem. However, the ECM did throw a code 42.
One example of a non present OD code is if both speed sensors have bit the dust at the same time. Unlikely, but possible. Mine may have been damaged from the wreck I had (shock, being another one of those conditions), but don't know yet. If I were to make guesses....which I love to do....the speedo, odo, and trip meter going crazy and the tranny not wanting shift out of first (a function of the fail safe circuitry) would point to the spd sensors. The vehicle was at idle and P when the speedo began climbing all by itself! Plus, the TM and odo began to advance....all by themselves! (Do-de-do-de....do-de-do-de....
) However, the speed sensors wouldn't explain the engine revving simultaneously. I really hope it's not the ECM. That would suck snot! Bad grounding somewhere could explain it, though....particularly at the ECM.
Anyhow, enough vaguery for the day. I won't be doing anything else with this vehicle until next week, probably. I've got another vehicle to work on. YAY!!!!!
02-04-2008, 05:49 PM
#35
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ok so ya i was wrong about what i disconnected. after closer inspection i actually located the dashpot and realized that the cap and filter element were missing all together. i put those on but problem still seems to persist although it does run better. if i let off the trottle fast idle falls below 600 but if i let off slow, it sits where it should at about 850. do you think the dashpot is still resposible for this
after closer inspection i actually located the dashpot and realized that the cap and filter element were missing all together. i put those on but problem still seems to persist although it does run better. if i let off the trottle fast idle falls below 600 but if i let off slow, it sits where it should at about 850. do you think the dashpot is still resposible for thisIt does indeed sound like the dashpot. Fortunately, they're not very expensive. You may be lucky enough to find a good used one.....mmmaybe. Best bet is a new one, though.
02-04-2008, 05:54 PM
#36
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I've been chasing the elusive hogs..Planning a hunt for next week and I just realized this is your thread . I'll catch up when I get home from work. Sorry Matthew at least I could have been here for support.Now I got two threads to keep at the top of the list.
02-04-2008, 06:23 PM
#37
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Hehehe....funny! You bump and I'll post. 
No need to apologize, either. It's fine. I know how enchanting hogs can be. I've got nine!
No need to apologize, either. It's fine. I know how enchanting hogs can be. I've got nine!
02-09-2008, 08:35 AM
#38
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Right....update.
I was driving out two days ago and the '92 just instantly and completely died. No power to anything. Pulled the EFI fuse out and starting inspecting all the other electricals....just kinda scanning, really. Didn't see anything wrong, put the fuse back in, and the truck started right up. Weird. Got to my destination, hours later, tried to start it again....nothing, again. Looked REAL close at EVERYTHING. The negative battery post terminal had a barely noticeable crack in it causing it not to stay tight on the post. The terminal's one of the thin, metal type clamps and the crack was right where the bend is from the circle....so, it was not obvious upon previous inspections. Soooo....this may not be the problem.....affecting the speed sensor operation/tps input.....but, it could be. I picked up a new one last night. We'll see.
I was driving out two days ago and the '92 just instantly and completely died. No power to anything. Pulled the EFI fuse out and starting inspecting all the other electricals....just kinda scanning, really. Didn't see anything wrong, put the fuse back in, and the truck started right up. Weird. Got to my destination, hours later, tried to start it again....nothing, again. Looked REAL close at EVERYTHING. The negative battery post terminal had a barely noticeable crack in it causing it not to stay tight on the post. The terminal's one of the thin, metal type clamps and the crack was right where the bend is from the circle....so, it was not obvious upon previous inspections. Soooo....this may not be the problem.....affecting the speed sensor operation/tps input.....but, it could be. I picked up a new one last night. We'll see.
02-09-2008, 08:52 AM
#39
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Right....update.
I was driving out two days ago and the '92 just instantly and completely died. No power to anything. Pulled the EFI fuse out and starting inspecting all the other electricals....just kinda scanning, really. Didn't see anything wrong, put the fuse back in, and the truck started right up. Weird. Got to my destination, hours later, tried to start it again....nothing, again. Looked REAL close at EVERYTHING. The negative battery post terminal had a barely noticeable crack in it causing it not to stay tight on the post. The terminal's one of the thin, metal type clamps and the crack was right where the bend is from the circle....so, it was not obvious upon previous inspections. Soooo....this may not be the problem.....affecting the speed sensor operation/tps input.....but, it could be. I picked up a new one last night. We'll see.
I was driving out two days ago and the '92 just instantly and completely died. No power to anything. Pulled the EFI fuse out and starting inspecting all the other electricals....just kinda scanning, really. Didn't see anything wrong, put the fuse back in, and the truck started right up. Weird. Got to my destination, hours later, tried to start it again....nothing, again. Looked REAL close at EVERYTHING. The negative battery post terminal had a barely noticeable crack in it causing it not to stay tight on the post. The terminal's one of the thin, metal type clamps and the crack was right where the bend is from the circle....so, it was not obvious upon previous inspections. Soooo....this may not be the problem.....affecting the speed sensor operation/tps input.....but, it could be. I picked up a new one last night. We'll see.
02-10-2008, 01:11 AM
#40
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I'm really thinking it is. I rethought all the symptoms from some difficulty starting, loss of power, erratic tach and speedo, tranny shifting, revving, the speed sensor/tps input code....all intermittent. I work the weekends, so no time to install the new terminal....maybe tomorrow before I go in. If it doesn't entirely fix things, atleast I got my hands on the tech shop manual at the local Toy dealer today. My friend in the parts dept. let me borrow volumes 1 and 2 for my year for a week. I'm going make xerox's of all the pertinent pages this week at my place of work. I swear, Pete, these manuals go into soooo much more detail than what we have available online. They're laid out so well. I'm trying to think of a way to share the resources within my capacity, but I don't know how it will be possible without more effort than I have time or energy for. Volume 2 is atleast 1.5"s thick!
