yayfortrees

Hey kovz, any update on this? Did this take care of your problem?

kovz

I got the new sensor in, and it hasn't stalled out on my yet, but then again, I haven't driven it much. I drove it down to Monro Muffler because a buddy works there and he said he would put the new fuel filter on for me. So I dropped it off there last Thursday and said take your time (he is just working on it when they are slow... ). He said it's a huge PITA to change that filter and he can't wait to get the truck out of there.
But back to the coolant sensor, that seemed to help solve one problem but the CEL light is now on and the truck is running very rich and the exhaust is blowing out black smoke when it starts up.

Does this sound like a TPS issue now? I should be hearing back from him today. He said once the fuel filter is back on, he'll put the computer on it and see what kind of codes it's throwing.

I'm getting so fed up with this thing. Still considering selling it and trying make most of my money back....

yayfortrees

Possibly a TPS issue. I was sure hoping that the temp sensor was all that you needed. I think you will be able to handle looking at and adjusting the TPS yourself, it's not all that difficult. We will answer any questions that we can. If you want a quick crash course in multi-meter use, let me know. I will share the basics of what I learned in school (MMI).

After re-reading this thread, I came up with one thing you could check before you check the TPS. Look at your dashpot. This is the little part that sits under your throttle pulley. (I don't know what it's actually called. Your throttle cable attaches to this and it's what moves on the outside of your throttle body.)

Your throttle pulley has an adjuster screw and locknut. The screw should rest on the plunger of the dashpot. With engine off, rotate the throttle open, and check to make sure the plunger on the dashpot comes up a little bit. When you let the throttle back down, the plunger should provide resistance to the throttle, letting it close in about a second. If it doesn't act like this, let me know, and I can guide you through adjusting it. This is also covered in the FSM, if you would rather just read it. I didn't use a tachometer as the FSM said, I just adjusted it to what felt right when driving. NOTE: I had to use some fine sandpaper and WD-40 to smooth up the tips of the plunger and the adjuster screw to keep them from sticking to each other.

After that has been checked out / adjusted, then move on to the TPS if necessary.

With help from the FSM and members here on YT, I feel confident that you can get this problem fixed. I know things like this are frustrating, but it's also a great learning tool. You can learn a lot about our trucks, and you will be surprised at what you will be able to accomplish.

Just a couple of months ago, I was starting on rebuilding the front end of my truck. I had been planning it for a while, and was planning on taking it to somebody to do the work. I had never dealt with T-bars, or control arms or alignments. After some reading on here, a few questions here and there, and the next thing I knew I was finishing up all the work myself. I saved a TON of money in labor, and I now understand my truck much better. My truck has never felt better, now that I've fixed most of the PO's mistakes.

Hang in there, and don't let it beat you up too bad. It could be worse, this could be your daily driver, and you could be relying on a bus to get to work and back!

kovz

Hey yayfortrees, thanks for the encouragement!

I thoroughly read over 4crawlers TPS adjustment page today ( http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml ) for about the 5th time... I think I have better understanding now of how to do it. Things are finally starting to 'click' and make sense! Like I said, I have a cheapo multimeter from Harbor Freight, but I've used really nice ones at school before in the lab (electrical engineer here, but I work with industrial power). I think the MM I have should be able to do the job on the TPS if I need to.

I'll see what my buddy says today. Hoping to hear back from him by 5:00EST. If I get the truck back tonight, I'm definitely going to look into the dashpot!

Thanks again for your help. I will continue updating until I get this thing figured out

ChefYota4x4

iTrader: (5)

Just remember, Kovz .......you have NO guarantee, after doing all that you have, then selling it, that the next "second daily driver" wont have EVEN MORE issues. Know what I'm saying? Once you get these tight, they are SUPER reliable. Drove mine to 256K Miles before deciding to do a rebuild(it's still purring, but it was needing about 800 in bottom end repairs in the near future, and a rebuild from a really good machinist I know will be about 1200....so why not, eh? lol).

You really need to get a Multi-reader on all these sensors, the wiring to them, etc.

"rich?" Sounds like it, and it could be that those sensors, 'TPS and maybe AFM' got out of whack due to the ECU(computer) working off a bad sensor. Just get at those sensors, ...you'll narrow it down. When tearing mine down, I took my injectors in for a full redo at RC Engineering, and they were REALLY bad. 3 were leaking, including my Cold Start Injector. My intake was also REALLY full of the infamous "Black Goo", and one of the vacuum inlet ports on the upper intake was COMPLETELY plugged up with that GOO. You can use seafoam to clean up the intake some....but I did a full 2 cycle(PCV and Brake Booster) intake Flush with the stuff, also ran it in the tank as recommended, and when I pulled the intake, it was STILL really disgustingly filled with black goo. If you pull the air intake into the throttle body, you can see if it's black and caked in there by opening the throttle and looking with a mirror and flashlight. I took pics like that using the mirror, then loaded them on my puter...HOLY CRAP was I amazed that this thing still ran with the amount of crap in there. I have pics of all my work on my tear down, engine removal on my thread, "Trying to make a decision", if you want to see what I'm talking about.

By the way, I just did a Fuel Filter, not long ago, and yes, ...it's a PITA....but it took me about 30 Minutes, with the engine still all together. But HEY, if your friend is willing to 'help ya out', why not! lol.

Good luck, man, and like I said, .....if you're gonna sell it, you're gonna sell it. But, as you get at many things, it makes less sense(if the compression is good, etc.), to get rid of it and then move into another possible nightmare, ya know?

kovz

Well I'm hoping I don't have to sell it... especially after putting all these new parts on it! lol. Although, I do have a 91 Mazda 4x4 truck sitting out in the driveway that runs and drives well, but has a cracked frame. Picked it up for $360 and I'm using some interior and exterior body parts for my girfriends mini truck project (bagged 88' mazda b2200). If I can swap parts and weld up/patch that frame, I may be keeping that for a 2nd daily. We'll see though...

Back to my toyota... when I first bought the truck in March, I did 1/2 bottle of seafoam through the vacuum system (used the line off the brake booster). Then I put the other 1/2 the bottle in the gas tank. About a week after that is when the truck started giving me all these problems and stalling out. That is when I gave it a full tune-up, new rad, new ecu, etc. At that time, I also took the intake off and cleaned out the throttle body and the butterfly gate in there. It was all kinds of gunked up!!!
So when I put the coolant sensor on last week, I had to remove the intake again and I looked in the TB and it is clean as a whistle still.

When it comes to autos, I am good at doing body work, body panels, wiring things up, suspension, exhaust, etc... but when it comes to engine related things and these damn sensors, it get's really confusing for me! Like you said though... it will all be a good learning experience in the end. I just hope I see successful results!

kovz

Got the truck back from my buddy at Monro last night. The new fuel filter is on and the temperature sensor (as stated before). The truck fires up every time now, and drives well, but as soon as I hit the brakes, push in the clutch, or put it in neutral, the idle surges. Definitely a sign that the TPS is bad or needs readjusted. In fact, when it is sitting there idling, if I bang on the TPS sensor with a hammer, the idle fluctuates, lol. Going to attempt to adjust that this weekend using 4crawlers how-to. Other than that, I think I finally fixed the truck!

yayfortrees

Wait! The idle surge sounds like the idle is set too high. You can read about this on other threads, but briefly, the ECU has logic, that if the engine RPM is higher than normal, and you're applying the brakes, it reduces the RPMs to possibly help you brake. Just by turning the idle back down, you may be able to eliminate the surging.

I know it sounds ridiculous, but my truck was doing the same thing and lowering the idle speed completely eliminated it.

And why are you banging on the TPS with a hammer?! That's supposedly a somewhat sensitive electronic sensor. It is probably still a good idea to check the TPS setting, and adjust if necessary. Hopefully it won't need replacement, but it might if it keeps getting hammered!

I think I mentioned the dashpot in an earlier post, right? Did that need adjustment? Once that is all squared away, turn the idle down a bit, and see if that takes care of your surging idle.

I hope everything is good to go for you. Thanks for updating, this tells me that a temp. sensor can be very influential in running conditions.

kovz

OMG, so pissed off at this damn truck.

Gonna start a new thread because I need more people to view this and it's no longer the temperature switch issue.

BTW, checked the dashpot and lubed it up. It was working fine. The idle screw is screw all the way in, as low as it can go.

highway

when i had the idle surge (mine had the adjusting screw all the way in) i took off the small coolant line at the throttle body and blew air through it from my air compressor and it works like new

ChefYota4x4

iTrader: (5)

Hey Kovz.....TAKE A BREATH.....'ahhhhhhhhhhh', lol. In all seriousness, I know how frustrating this can be...but trust me, EVERY vehicle has it's 'querks', and you'll have to fiddle with ANY older codger. But these motors are REALLY reliable, once you get the 'querks' figured out. So, a list of things you've checked/replaced would be good.

1. I KNOW that the IACV can cause major problems, including relating to coolant Temp/Idling. Basically, when it's cold, you pinch off the large hose from the front of the IACV, completely, and see if your idle drops noticeably, then, wait till it reaches normal oper. temp, pinch it off again, and it shouldn't change much at all, if any. It might need cleaning(which I'm having trouble finding links as to how is the best way)

2. Go step by step through the 4Crawler TPS adjustment link(I'm going to do the same when I get the newly build motor back).

3. Check all your vacuum related emissions components. EGR, Modulator, then check your vacuum control components on the valve cover(VSV?...guys?), and (AC Vac. regulator?).

4. If you've not done so, I HIGHLY recommend making sure your intake AND throttle body are cleaned out(I know you said Throttle body, but my problem was in the actual upper-intake....Not sure if you pulled the entire intake or not). Upon taking mine out, I realized that the rear inlet to my upper intake-to- I believe EGR was COMPLETELY clogged shut. It was so hard and gooked up, it took me 5 minutes to clean/scrape it out. Not to mention, the outlets to the Injectors can get really clogged up.

I'm not sure if you've done the intake cleaning, but I recommend removing it, if it's really clogged up, instead of 'Seafoam'. I think the Seafoam might be fine for routine maintenance, but when it gets to where I was, not even two treatments, properly done to the tee, removed HARDLY ANYTHING! It's tedious to mark everything off, remove it, ...but you could have the Injectors tested/reconditioned(I have a great place if you need a number,....VERY reputable and reasonable), then start with a clean(AT LEAST UPPER) intake system. I know the intake valves will thank you as well!

Sorry I've not gotten back to you sooner,...I'm rebuilding/reconditioning pretty much my entire truck...so I've let the 'subscribed' list go for a bit too much. Sorry man! Also sorry if you've tried all this, I just didn't feel like reading through it all again, lol.

ChefYota4x4

iTrader: (5)

Sorry, the vacuum hose that was clogged COMPLETELY shut was either the PCV or vacuum line to the Brake Booster(EH?).

Can you go over, Kovz, exactly what your truck is doing? Like, :When I start it, cold..... Then, when it's warming up....., then, when it's warmed up..../ Does it smooth out at any point? Or, are you having this bouncing/erratic idle at all times? Sorry, you don't have to...I'm just curious how different it is from the time you started.

kovz

Here's the link to the new thread:

https://www.yotatech.com/forums/f116.../#post51440094

kovz

Well I'll try to explain this stuff for a final time.

The truck has a very difficult time starting from a cold start. I have to hold down the gas pedal to the floor. Once it starts, I have to keep giving it gas. If I let off the gas and it idles, it will stall out.

Once it starts warming up, I can let off the gas and it will idle fine. The idle is high and fluctuates. At this point, I can DRIVE the truck with no problems.

Once the truck is at running temp (warmed up), it stalls out if I give it ANY gas at all. Literally just touch the gas pedal and it stalls out.

When the truck stalls out or I shut it off, it's difficult to start again. It just cranks and cranks. If it does start, the idle is very low and the truck shakes like it's about to stall. Again, if I touch the gas pedal even ever so slightly, it will stall.

Once the truck cools down again, I can start it, give it gas, and drive it.

Here is the huge note: This problem started happening BEFORE I did any maintaince to the truck. The only thing I did was put seafoam in (brake booster vac line and gas tank) and a week later it started causing this problem. It was after this problem started happening that I tried cleaning the TB and probably screwed up the TPS with throttle body cleaner. I also gave it a full tune-up (cap, plugs, wires, rotor, air filter, fuel filter). So what do you think would cause this problem? Clogged cat? Clogged FI's or leaking FI's?