Allyia

oh thanks for those links,they help a LOT.
one last question of the day is;

Will the tps being bad make you have to advance the timing far ahead to get it to run right?
(you might have all answered that before, but i cant seem to find it if you all did... sorry about that!)

94x4

Sorry about the "blonde" joke (you're strawberry, right? )

Are you managing to get anything sorted out ?

About it stumbling when you hit the gas after the adjustment... that could be because while you may have the correct timing set, you still need to readjust the idle air-fuel mixture (which would eliminate the stumble and "popping") to get it to run smoothly... damn, that screw would certainly come in handy for that, huh?

Stay at it and you'll get it and I'm still waiting for you to yank the valve cover, so get to it!

Allyia

ok you opened that door... lol
how do you ajust the air fuel mix on a EFI? I thought the computer did that!

oh yeah... that missing screw I knew I forgot something today... damn!

and the %#*@^! valve cover gasket! Arrgg!

dont worry I'm going to pull that cover very soon.

oh yes, its all starting to make sense to me.... sort of.

94x4

So...., If not blonde by nature, then blonde in spirit, huh?!?

Seriously though, there's a screw on top of the throttle body.... wait, you have EFI on an '88 ???

superjoe83

its still there, big flathead screw right next to the rubber boot

94x4

And if it is there and you don't see it, look under the little rubber plug in the same area and you'll find it there.

Allyia

there is a big flat screw in the top of the throttle body, I aint messing with it till I get a few things understood better in my head.
I found this so I can go to sleep peacefully.... it sums up my problems, and confirms you guys were right.

"Symptoms of a bad or mis-adjusted TPS include:

Varying idle speed
Hesitation while accelerating
Poor fuel economy
Inability to correctly set base ignition timing
I.e. you jumper the timing check connector and the idle and timing don't change"

I need a better multimeter to set it right. more shopping.

Allyia

oh the screw missing is the dashpot screw not the throttle stop screw... my mistake.

I'll scavange one off the other truck.

2ToyGuy

Why not? I have EFI on my 87 4Runner...By the same token, she mentions the throttle body, and yet talks about the thing backfiring through the carb. Which is it? There are very few carbed EFI engines out there...

Multimeters are easy to use, actually. They have three main "categories": Volts AC, Volts DC, and OHMS. I bet you know the difference between VAC & VDC, so we'll leave that for now. Ohms is a measure of DC resistance, or how much a circuit resists the flow of electrons through it. AC impedance is horse of an entirely different color, and not important for this. Under the Ohms category, you usually have several possible scales, normally starting at 200 ohms and going up to 2K, 20K, 200K, etc. K means thousands of ohms. So, 2K means 2 thousand ohms. When you switch into the ohms category, and hold the meter leads from touching anything, including each other, the display will show you what "infinity ohms" or an open is on your meter. Some show a symbol of some sort, some show a 1 with no decimal points behind it, just depends on the meter. But you need to know what "open" looks like. Make sure when you go to measure a resistance, you have the scale set to a reading higher than the max possible. So, if you're measuring something that can max at 3300 ohms, for example, you need to have it on the 20k scale. I also like to check that the meter is functional, by shorting the leads together and making sure the meter reads 0. Checks the leads, the meter battery, the fuse, everything. Another hint: NEVER apply the leads to a circuit with voltage in it when in the OhMS scales. It'll blow the fuse in the meter, and possibly even destroy the meter, if the fuse is a little slow. Another hint: Make up a set of test clips for the vehicle, with a male and/or female pin that will fit into the plugs or sockets in the vehicle, and an alligator clip on the other. That way, you can plug it in to the TPS, for example, clip the alligators to the meter leads, and that leaves your hands free to make adjustments, write down meter readings, whatever.

Sorry, but a multimeter has been one of my cheif tools all my working life. I got pretty good with one after a while Hope my mindless rambling helps a little...

Allyia

"and yet talks about the thing backfiring through the carb."

I mean the intake where the air filter is, thats where the popping noise comes from.
my mistake... lol

that mindless ramble was perfect... add that to what I kow and that = much more.
THANKS!
my MM has a needle and a scale and one ohm setting so i am going to pick up a better digital one with mutiple settings.
then I can check the TPS correctly and either say it it or isnt bad.
one step at a time right?

gotta run, busy day... THANK YOU!!

94x4

O'kay, did'nt realize that they did... and now I know.

Also, with her mixing part names around, it is a little confusing and makes it a little difficult to give the proper advice, but you've got to remember: "...if not blonde by nature, then blonde in spirit..." (just kidding Allyia)

There's never any need to apologize for giving good advice that passes along useful 411 that people can use 2ToyGuy

And Allyia, I found a good digital multimeter at RadioShack (I think that Home Depot may also carry them) for cheap that works really great. It comes in a small, dark grey case that easily fits in your pocket and, due to it's unencumbersome size (approx. 2" x 4"), is very easy to work with as it does'nt get in the way.

Keep up the good work all.

2ToyGuy

Those Radio Shack MM's are OK, not the greatest, but for this, not bad at all. Surprisingly, both Home Depot and Lowes carry fairly decent MMs at a range of prices and capabilities. I would get one that is decent for a variety of uses, but still fits within your budget. After all, they're good for a lot of things besides vehicles: checking household appliances, home power circuit problems....lots of things. And yes, great for teh TPS, AFM, alternator, troubleshooting teh ECU, etc, etc. Even good for tracking down broken wires.

I have a bad habit of rambling on sometimes. It comes from not knowing how much the tagret audience knows, so I feel I have to fill in background, and try and keep it simple (K.I.S.S.!), but still pass on what I feel they should have...So I worry that I've gone on too long...it's kind of a catch 22

Any way, glad I could help. Hope you get this thing resolved soon. My brain is getting sore!

PirateFins

Ok go back and look at the page you linked to.

Fuel Injected Engines

Connect a timing light to the engine following the manufacturer"s instructions.

These engines require a special type of tachometer which hooks up to the service connector wire coming out of the distributor. You may also obtain an rpm reading by hooking the tachometer lead to the IG (-) terminal in the check connector found on the inner fender well. As many tachometers are not compatible with this hook-up, we recommend that you consult with the manufacturer before purchasing a certain type.

Start the engine and run it at idle.

Remove the rubber cap from the check connector and short the connector at terminals (T-E), as shown.

Loosen the distributor pinch bolt just enough that the distributor can be turned. Aim the timing light at the marks on the crankshaft pulley and slowly turn the distributor until the timing mark is at the desired readings as listed in the "Tune-Up Specifications'' chart. Tighten the distributor pinch bolt.

Unshort the connector.

T-E are the two pins you short to set base timing, not B+ Ing-.
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Allyia,

Please perform 1 test for us so we can clear this up.
Start up your truck as it is right now. Let it warm up and idle (don't give it gas just idle).
Put your timing light on it and note what *'s it is reading
While running short out pins T & E1 (nothing is going to fry while the truck is on).
When you short out the connector pay attention to the idle and let us know if it drops.
Take a timing reading while still idling and with the jumper still in. What is it reading now?

If the first number is higher than the second. Then you are jumpering out the correct pins.

If those pins do not have any effect then your TPS is out of adjustment and you will not get anywhere until it is set properly and then the timing is set properly.

I have mine set for 7* base (slightly advanced)

Let us know what the readings are?
This is so we can take the guess work out of where you are at.

TPS trick when you get to it,
You can remove the bottom screw without removing the T-stat housing. Use an angled phillips screw driver, or a small 1/4 drive socket wrench with a 14"socket and a small phillips bit (from a screw gun). Then replace with an allen head when you re-assemble.



Stick with it we all can get this worked out when the info gets clearer.

One last thing where are you located? There might be another YT member close by that could lend you a physical hand instead of the mental ones we are providing.

2ToyGuy

You're right, sorry...
I am far from from perfect, and I'm glad ther's someone around to help catch the screwups!

PirateFins

No need to apologize we are all here to help out and the effort is what counts!

just making sure everyone is clear as to which 2 pins it is to set timing and pull codes (one and the same).

But I stll place money that her TPS is not adjusted within spec at idle and that is what is throwing the timing of (as high as 20*). Get that meter girl!

2ToyGuy

Hear hear! That and/or the cam. I'd like to know where the cam timing mark is...

94x4

*ditto*

Allyia

Ok... here is the deal of the day.

I DID (last night) do the T and E1 jumper thing while running.
no effect at all on idle.
so as I said previously, I did it again, this time I turned the key to ON, jumped the pins and read a error code 51, and then started the engine. at this point giving it gas failed to advance the time and it nearly stalled, so I was sure the jumper was doing its job.
I set it to 8bdc.
pulled out the jumper.
no effect on idle.

runs like crap, so I advanced it back to where it will run well.

so NOW, the timing is at about 18-20 btdc.
This morning I had a chat with the mechanics boss, and I mentioned the TPS, to which he replied "of course thats whats wrong thats why you cant get the timing to set right..." and he took a multimeter, unplugged the TPS and did a few tests.... much like or exactly like the ones on 4crawlers pages.
he said the part of it that regulated the idle is not working at all, nd the other parts are "somewhat off".

he showed me how to watch the timing mark as the engine was at idle and it does move back and forth a bit, and the engine does have a slight intermittent miss when idling I didn't notice...

so, picking his brain I ask how much for him to put a new TPS on and then do the emissions test on Monday, he said he would call back...

meanwhile, I call 4 part stores and a Toyota dealer to check out TPS prices.
he calls back and says $119 for the TPS, and $30 to put it on and adjust it.

he beat my price hunt the cheapest I could find was $149+tax.

So for @ 150 bucks I'll have a new one in and it tuned right, or if not he is always a fair guy and I can bring it back for him to re-tune if it seems like its not adjusted right.

this solves 2 problems;
>it exceeds my $150 emissions repair for an exempt sticker, if it fails.
>for the price I can buy just the sensor I can get it and have it put in, with someone to blame if it isn't done right.

also he will let me watch over his shoulder, and I can absorb a lot of info that way..

I can experiment on the other parts truck I have to make run "ok" to move around out of my what when needed, if I screw that one up, its no big deal, i can keep making mistakes till I get it right and relax while doing it.

Good deal all around.
he said he has seen that timing problem before quite a few times on lots of cars, and its always the TPS. He did agree, it MAY not work and it MAY be something else, but he highly doubts it, as the symptoms fit.
the advanced timing, the lack of response to the jumper trick, and another thing I didn't really notice because I haven't driven it much at this point, he said puttering around in 4th, you can feel it surge sometimes, then at times the valves start to clatter, then back to running fine again (yes I took it for a ride and did that and damn if he wasn't right...)
he said more bad feedback from a failing TPS evidence.

So.... Monday sometime I will find out for sure if the TPS fixed all its problems, as it will be NEW. (and not put on my me taking my best experimental guess on putting it in/adjusting it).

don't worry the valve cover is mine, thats an easy job. I want to clean/paint the thing anyhow while its off.

I will keep you updated.

oh i did get that dashpot screw off the other truck and put it in this one, it improved the smoothness of deceleration quite a bit. now you let off the gas and it slowly drops its rpms, before it just dropped quickly to an idle when you let off the gas.... much better!

I'm learning, thanks guys!

94x4

Yes, please keep us updated and I hope that the TPS works out for you and/or is at least a step in the right direction.

Also, even though I (and others here) would like to check out your potentially having a cam in there, the TPS could be the cause of all of the problems and would rule that out (darn it), but it would at least save you the labor of having to mess with it, that is, unless your valve cover is leaking and so, does need to be replaced. Time will tell.

Good luck.

2ToyGuy

Great! Glad to hear that things are finally coming to a (hopefull!) resolution. Yes, I've heard of the TPS causing the idle problems and timing problems. If the ECU doesn't "know" that the TPS is shut (or at idle) it never set's the timing correctly, and it get's a signal from the TPS telling it when it's at idle. Also glad you've got a pro to at least look over your shoulder. You can learn an awfull lot that way. I have found that someone can tell me something a gazillion times (and that's a lot!) but until I stick my hands on it, I don't really LEARN it.
Just a hint: If you ever go to do a TPS alignment, do it with the throttle body OFF the vehicle. It makes life soooo much easier!

Good luck, and I'll be waiting to see what all else transpires in the next episode of "Days of our Toyotas"