thook

Alright well , if so then I hadn't tried testing the timing with the jumper wire off. I did test to see if the jumper being installed would effect the idle....and it did, but only on the first out of three tests. I repeated it to shoot for repeatable results. What am I doing wrong here? What do you mean it's not still not going in to base timing? Why would it not? I checked the CEL to see if it flashed on every three tests above and it did...verifying the connection was good at the tester.

thook

Aha! The damn TPS again!!!! Where's that dynamite?!!!!

thook

Geez! I forgot to mention that the idling gets much better as the engine is warmed.....still dies after throttle let up, though.

04 Rocko Taco

you can check all of the codes in any 95 or older vehicle yourself, almost every vehicle has a "jumper wire trick" to get the CEL codes. 96 or newer is OBDII and no jumper wire trick, but!!! Auto Zone will read the codes for free and tell you what they are, no diagnostic work, but they will tell you what the codes say. But they dont know what causes them. TRy them next time.

thook

Thanks for the tip, Rocko. And thanks for joining in on my looooong ongoing dilemma!
Thing is, the nearest Auto Zone is almost 30mi. from where I live. Inconvenient, to say the least. Nevertheless, I've got a 92'....so I've been doing the jumper wire. It's free, convenient, and I don't have to spend the money on the gas!!!!LOL!
I've just been reading some threads on the same issues I've been dealing with and discovered my TPS may be on backwards.... ...which would explaing a number of things. I would swear, though, in the Haynes manual it's on the way I put it in....terminals facing away from the manifold. In the FSM, it's facing toward the manifold. In one thread, the fellow had his on backwards (mechanics fault), switched it around, set it correctly, and was able to get his timing set properly.
I'm just about to get back to my vehicle (and the Haynes manual), do some comparison checking for the possible discrepencies, and see what I get. If I find the Haynes manual is incorrect on the TPS terminal direction, I might have to burn it!!!! If I find that I was just looking at wrong, I may have to have my name legally changed to Dumbass!!!
Regardless, I must say through all of this I've learned more than I ever expected to about getting a motor running properly. It's going to save me a lot of money at a mechanic. Hell!!! I could open my own shop and know more about Toys than some of the "qualified" mechanics in my area. I'm not kidding!!
Anyhow, I'm gonna do my thing and post my re-re-results later.
Thanks all! Especially you Supra! I'm completely grateful for your help over all of this time!!

04 Rocko Taco

Heres wishing you the best of luck, Keep us posted!!!

thook

Thanks again, Rocko!! That's very kind of you.
Haynes manual....made of paper! Burns easily! I did see the diagram correctly. But, not to be too hasty...I have yet to really varify by factual evidence and conclusive personal testimony that what position the TPS is facing makes a difference. I haven't been able to read it anywhere, nor did it make a lick of difference switching it around. I know the sensor is not bad. I've tested it multiple times and always get the same value reading for ohms. On that subject, the jumper wire still has made no difference in the idle, yet it still signals the CEL to come on. Which is suppose to mean TPS out of proper adjustment. ????
Where it stands:
Followed procedure....warmed up to temp, installed jumper (no idle response), tested with light and remains around 10*BTDC...although, the mark does jump around, but not to far from 10. The idle is around 800 rpm. Then I tried advancing timing to 12 and then 15. The only difference any of this has made is that now it doesn't completely died after throttle release. Just wants to. It lopes and chugs.
One thing I noticed was that at one point the vacuums switching valve (I'm pretty sure it was that) was clicking when the motor would chug. Then there was a point when it stopped. ????
Hmmm....I know there's something I'm missing here. Well, if the jumper doesn't make a difference in idle, then I'm not getting into base timing, eh? Therefore, trying to set timing is pointless, eh?
So, I've got a Haynes manual....I'll use to beat the guy who sold me this motor. But, not before I light it!
Anyone with any ideas, please....feel free to shed some light on my aching mind.

rdharper

Disconnect the TPS. Start engine. If RPM's are high, TPS was not adjusted correctly, or not installed correctly etc.

While disconnected, see if engine dying after blipping accelerator is gone.

thook

Haha! I was just reading a post you made on this subject and how you fixed you problem. I'll try that. However, my wife just back from a test drive and said it was running better...there was a point when she "felt it kick in". That raises a question! A mech told me that when you do adjustments like this it takes the computer a little time to adjust and make the vehicle run right according to new "settings". Is this true? It doesn't appear that way as some folks, such as you, got immediate results.

rdharper

Yes its true. However disconnecting the TPS effectively cuts the TPS out of the equation.

thook

I did the test....again. Sorry Richard, I forgot you posted that already. It makes all the difference having a good TPS, though. When I tried it before, it changed nothing. Of course... the TPS was faulty!
Okay, this time the idle RPM jumped up with the TPS disconnected, and the motor didn't die with the blipping accelerator gone. So, readjusted the sensor as you explained ealier in the thread, but the jumper still doesn't drop the idle. I know I'm not doing something right. I'm going to print up your post so I can have it out there with me while I'm messing with the adjustment til I understand what's happening. Too bad I can't just hook myself up to this computer and inject this information like Neo in "The Matrix". <<<I know Toyota!!>>> Ha! That would be too easy! But, then mechanics would have no need for aspirin....
One more thing...Richard, you've gone out of your way to post and explain this info about the TPS and all in this and other threads. I certainly hope you're getting all the thanks you deserve for sharing it. You have my gratitude.
Good posting! (regularguy, too!)
https://www.yotatech.com/forums/show...ng+base+timing
Very well laid out!

rdharper

This is "good news", as it means your original problem is, and has been, the TPS setup. If you can drive it and detect no other problem except the ECL coming on, then all you have to do is get the TPS setup correctly.

It is unlikely that two TPS's are bad, although possible. Especially as you've measured one or both of them off the truck, given normal readings. (the "jumping around" you've noted is normal for the range you were using).

I'm wondering if you've read the explainations on how to make sure the TPS is mated to the shaft correctly. Apparently this is a common problem.

Here is what you should try now:

0. Adjust the high rpms down to 800, with the TB idle adjust, while the TPS is disconnected.
0.5 Reconnect the TPS
1. Make sure you have it mounted correctly. (lots of posts on this)
2. Adjust the TPS while the motor is running. You want the higher rpm case as the idle detect (now set to 800rpm). It should be just detected, meaning you want the setting very close to switching to the lower rpm, but set to the HIGHER, 800rpm case. That is the ECM detecting the physical throttle idle position. The lower rpm case is the ECM NOT detecting the idle position, and therefore forcing the lower rpm case.

thook

Thanks a bunch Richard! I started thinking last night that the instructions you are giving at this point is what I need to do. But, because of what I was reading and the way it was written, I was setting it at the lower idle case. Wow! I haven't tried setting to the higher case yet, but I know already what exactly this means and what's going to happen. I will get to it later today. Gotta move another wash machine first! Later!
EDIT:
One question...I was going back over the description you gave of your procedure on another thread, and what you said leaves me thinking that you had the E1-TE1 jumpered while you did the TPS adjustment. Did you?

thook

Update:
So, I did everything exactly the way you described. Warmed it up, disconnected the TPS (which is installed correctly on the post), adjusted the idle to 800 (had to turn way far in..???), reconnected TPS and adjusted it just to the high/low rpm edge...on the high side, and, finally, went to set the timing to 10*BTDC. Thing is, the CEL came on flashed a code 41(TPS) and the motor didn't shift down when I jumped the terminals. Which as I understand is the clue that you are in base timing mode. Correct? So, I disconnected the battery and waited thinking maybe the computer wouldn't make the shift when it's throwing a code. Went back to start the engine and it would not start. It turned over and tried to start, but then died. Okay....so I'm thinking TPS STILL not adjusted right. Well, I had to twist the idle screw back out and advance the dist. just to get it to run again. Then, started all over from there. I left the idle where it was, screwed with the TPS...again, then....well, you get the picture. In the end, after following the procedure three times, and even deviating from that a couple of times to keep the thing running, I'm left with the same problem. It WANTS TO DIE! If there is a consciousness to this vehicle, I'm very inclined to believe it just wants to be parked and have the sunroof back with the stereo jamming. I suppose I could set up a bar in the back, pull the seats, and put in a small hot tub. Hmmmm.....
I haven't given up yet, but I've been almost there more than several times. I have to wonder why everyone else seems to be able to resolve the same issue so easily...and permanently. Frustrating!
On a different, but related, note I read another thread where the fellow gave his own method for setting the TPS by hand. Only he describes the proper setting to be different. He suggested starting the engine, of course, turning the TPS down to lowest idle, then back up to where it jumps, then back down just to where it shifts again to low, and then set it at that point. <<Huh?>> Well, that's the way I did it yesterday and, as I said, my wife said there was point when it kicked in and started running good. It didn't die at stop lights, it didn't die going down a hill, or basically any time she let off the accelerator. It reached low idle and stayed there. Needless to say, I'm confused by what seems to be this contradiction. Of course the vehicle started out running a bit poorly when she drove it, but eventually got better, Today....well, I may have to look into that hot tub mod.
I'll keep messing with it. I do consider the ECM has to "catch up" with all the changes.

rdharper

Lets back up a step. We started down this path with the TPS disconnected showing proper idling, no engine stutter or dieing etc. Right?

You could always back up to that step and recheck that behavior. If it is now not working with the TPS disconnected, you have more than one problem. But if it is still working in this condition, then there is still a problem with either the TPS setup, or a related less probable issue, such as wiring to the ECU or the ECU itself. But don't panic, this is very unlikely imho.

Ok, so re-disconnect the TPS and verify the thing starts and runs normally in its current state. You might even take it for a test drive and see how it "feels". Let me know what you find. My guess is it will run fine.

thook

Thanks for your patience, Richard. Mine is wearing thin...with the vehicle, though! LOL!
I'm glad you brought that up. There was a couple times when I pulled the TPS wire off and the motor jumped in RPM and the died. I did mess with the timing in all of this...and the idle. That's it! But, before that, when I pulled the wire, the motor didn't die once. ???

rdharper

Btw, when you set the idle, make sure the dashpot sitting to the left of the accelerator cable end, is allowing the accelerator to butt against the stop plate. As opposed to a sticky dashpot holding the accelerator open just a bit. This variable would confuse the idle setting process, causing you to turn the TB idle adjust, clockwise, too far, to bring down the RPM's to 800.

If that is happening, just push the accelerator closed, and come back to the dashpot after setting the idle.

thook

I took a few days off from the motor and gathered parts to do the ISR mod....just to eliminate the crack in my intake tubing as a possible factor. It turned out rather well, I think. I had so much trouble getting the parts laid out as described in the ISR tech archive (long, boring story) that I wound up getting 2.5" coolant hose from NAPA (cheap!!) and using a 45*angle piece of sched. 40pvc. It all worked so beautifully and easily I'll have to get a pic posted with a brief write-up in the appropriate forum (?) just so anyone could have some idea for an alternative to what's already been done. That is if anyone would be interested, or have as much trouble as I did getting it all together like the tech archive.

Anyways! Did the mod, quintuple checked the TPS settings, and fired it up. Ran great for the amount of time it took for the motor to fully get good and hot, and then came the slow and eventual decline. It chugged and loped, unless I gave it gas, and kaput!!!.....DEAD!!!! OH!!! This is with the TPS disconnected, too. Vacuum leak?

PAhydrohead

Did you plug the threaded port yet? If not, I would guess you have a big vacuum leak at this location! P.EC-24 of the FSM..edit..(I'm looking at the Toyota FSM not Haynes) talks about testing the EGR valve but it sounds like there should not be any vacuum on the EGR at idle. Applying vacuum to the EGR at idle = dying engine so could you have some of the vacuum lines mixed up? The EFI System Description Diageram on P.FI-99 of the FSM indicates that the EGR temperature sender is California only so maybe you are just missing a plug in that threaded port.

The wires recently broke off my EGR temp sender (bought my truck in Cali) and now the check engine light is on but the engine still runs the same as it did before so it must not be a critial part.

I know this didn't provide much help but I would definately plug the threaded port for the temp sender. Good Luck

thook

Thank you for taking such time, PAhydro.
I blocked off the EGR system a month, or so, ago. But, there could be some vacuum lines mixed up elsewhere or not plugged properly. I don't know. I will have to look at some pictures of a properly assembled engine to compare.

You ought to check out putting a 10amp 1/4w resistor on your gas temp sensor wire. That will cure your CEL. The EGR doesn't seem to be critical to the operation of the motor, just the emissions. I would liked to have addressed that myself, but funds are limited for a new EGR valve.

Thanks for your input!!