1992 3.0 running ruff (new TPS sensor)

[ClintR2]

I have a 1992 4runner 3.0 4wd that I bought for $400. The owner told em it need anew TPS sensor. When i drove it home it had very little lowend power. I figured it was the TPS sensor. So i bought a new. A Genuine Toyota one. Also new spark plugs and wires. Cleaned out the throttle body and intake. Got tons of gunk out. Put it all pack together and hard to start and runs horribly.Back fires, no power will not rev over 2500 RPM's. Unplug the sensor and runs alittle better.
I assume 2 things.
1. bad TPS sensor
2. i did not adjust the engine out properly after install.
(i have moved the TPS sensor around and advanced the the distributor and not much change except faster idol.

I have been looking around online and not really found any answers.

Can someone please help me figure out what the problem is.

follow this link to watch the video.

https://urldefense.proofpoint.com/v2/url?u=https-3A__youtu.be_g4rcOQmtCKI&d=DwICAg&c=Iej4I5bEYPmgv5l2sS6i8A&r=9l_v9g0ysxrqK9uJuwCGUP0_MUjPBMKKnASHU5AEJms&m=DiOd5UhwL27dnZnZfjtB4KwBm5sykNTvJW-Ppyblbns&s=JxAKIr7XbR3yGm3UFSb427Z8L07QkDYBml5OiVZnylY&e=

 

[mholme]

It’s not really a good idea to blindly make adjustments to things. You can follow the procedures in the manual to set the TPS. You have to set it properly, there’s no way around it. But before you do that, I would verify your timing with a timing light as well as physical timing marks. It was 400 dollars for a reason. You have to start at ground zero and work your way up. That means checking compression, timing, vacuum leaks, etc. Lots of things.

 

[xmindbender]

It’s not really a good idea to blindly make adjustments to things. You can follow the procedures in the manual to set the TPS. You have to set it properly, there’s no way around it. But before you do that, I would verify your timing with a timing light as well as physical timing marks. It was 400 dollars for a reason. You have to start at ground zero and work your way up. That means checking compression, timing, vacuum leaks, etc. Lots of things.

ditto on compression check... its a matter of ruling things out and condition of valves, rings etc is a solid step... no sense chasing symptoms at this point until you know the basics are intact. Also, if theres gunk in the intake... there is likely gunk throughout as that is past the protection (filters). Check things off and move forward. Science isn't about proving what works but disproving what doesn't... and this is all about that. you are getting to know your new rig... nothing wrong with that!
:redbrick:

I measure these types of projects by how much beer it takes to get it done. :beer:

 

[ClintR2]

You are both right. I completely agree. These were the few things that I saw right off the top. The wires were damaged, changed new plugs while chaning the wires, tps sensor was not even screwed on, and cleaned out throttle body b/c I had to take it off to get to sensor.

Let’s theortically say I go through the procedures. And I am still getting these results.
Then What?
I know it was $400. I totally am a believer in you get what you pay for.

Could someone guide me to the Best procedure in installing and adjusting the tps sensor.

Thank you

 

[xmindbender]

You are both right. I completely agree. These were the few things that I saw right off the top. The wires were damaged, changed new plugs while chaning the wires, tps sensor was not even screwed on, and cleaned out throttle body b/c I had to take it off to get to sensor.

Let’s theortically say I go through the procedures. And I am still getting these results.
Then What?
I know it was $400. I totally am a believer in you get what you pay for.

Could someone guide me to the Best procedure in installing and adjusting the tps sensor.

Thank you

Some folks here might get a little snarky and point you to the multiple resources available to include this site and youtube. Often we just need a little company and input... snarky is bullshittery.

The bottom line is that there are only so may possibilities as to the problem though it could be more than one issue stacking up. I would consider starting with compression so you know what you have down inside… no sense in chasing your tail if the valves are shot etc. If there are any issues with compression…do a leak-down to pinpoint. Given the gunk, it may have been running dirty air which is problematic.
Could also be bad fuel if it has been setting long or pressure/filter issue. Spark? Run it at night (dark) and see if you have 25,000 volts escaping somewhere etc. Vacuum is huge and could be hose, intake gaskets etc… put a gauge on it. I spray small amounts of starting fluid in suspect areas to see if idle changes indicating leak… be careful tho and wait between applications so it does not build up and go boom.
The bad news is that once you get it running proper, it is still a bit of a dog. Document what you check and hopefully it is an easy fix. Sometimes you get far more than you pay for and as long as the rig isn’t beat to hell with multiple other issues… could be a decent buy. Or, could be a parts hound. Either way you will come out ahead at $400.
Youtube is your buddy at this point. Maybe run this thread with updates so it is documented for you and others. There could be a cornucopia of info here.

Continue to give input and you will get it back.

 

[ClintR2]

Here is the background up on the purchase. I bought this for the Gambler 500. If you are not sure that this is. Check it out. Pretty Cool. So from the start it was a gamble. Once I saw it was thought it was a steal.

No smoke out tail pipe. No strange engine sound (knocking, girding...)

I literally filled it up with fresh gas. I drove it and it drove fine. Just not much power on the lowend. I drove it home that was a 80 mile drive. It drove fine just need a good running start to get up to highways speeds. Would start to lose acceleration going up hills. I was able to get up to 85 MPH and hold it between 70-85 the entire trip.
(the TPS sensor was not even screwed in)
So all in all it drove fine with just not much on the lowend power. First gear not not the best.

So I started to do some research and found out that 4Runners are freaking Awesome! I have had several Jeeps (restored 2 of them) CJ's, Jeepsters, Cherokee's and Liberty.

I started just doing the basics to get it running better. Spark plug wires were spliced, spark plugs are cheap and TPS sensor was not connected. So i figured i would start there.

Cleaned everything and when i say Gunk i mean not slime in the intake. Just dirt and carbon but dirty in my opinion. So i cleaned it thoroughly and throttle body.

Put it all back together and cranked right up. However, was still not running right. I figured it was timing b/c right when i cracked it up it was running to high on the rpms. I saw were some people adjusted the distributor and the TPS. So i did my best to do it by ear. I know better than this, but thought i would give it a try.

So help this helps with they understanding on the vehicle and that it runs well just not alot of lowend torque. From what i researched the issue with the lowend torque most likely is the TPS sensor.

I will start with compression and timing to make sure it is adjusted properly.

 

[xmindbender]

Here is the background up on the purchase. I bought this for the Gambler 500. If you are not sure that this is. Check it out. Pretty Cool. So from the start it was a gamble. Once I saw it was thought it was a steal.

No smoke out tail pipe. No strange engine sound (knocking, girding...)

I literally filled it up with fresh gas. I drove it and it drove fine. Just not much power on the lowend. I drove it home that was a 80 mile drive. It drove fine just need a good running start to get up to highways speeds. Would start to lose acceleration going up hills. I was able to get up to 85 MPH and hold it between 70-85 the entire trip.
(the TPS sensor was not even screwed in)
So all in all it drove fine with just not much on the lowend power. First gear not not the best.

Its hard to overstate this motors lack of power. You can measure 0-60 by commercial break. And hills are monotonous. But I grew up with a ww2 willies (ford made) that topped out at 45mph... but would climb trees in 4-lo. I am going to live with mine for now and put in a 3.4 in another 80k if not sooner. Sounds like you are on the go. I went through the service records on mine and it has been over 90k since it had a tune-up. Serviced every 3k but lapsed on the plugs, wires, rotor etc. I hope that helps the little doggie run a bit faster.

I used to tune by ear then light it up and see where I was... sometimes I rocked it and sometimes not so much. I had a friend who was fiendishly good at it and always found the sweet spot for any given day/activity. Better back when the ignition was simple and with points. Check the timing advance while in there as it allows the timing to advance to handle acceleration. it runs off of vacuum... still think that is a very likely culprit or contributor. Did you find help with the tps?

 

[xmindbender]

Here is the background up on the purchase. I bought this for the Gambler 500.

I checked it out and the gambler 500 seems like fun. I like the sarcasm involved. Theres always those stories of a guy on a huffy outrunning the spandex laden, 18lb mountain bike riding mock pro's while having way too much fun. Saw that in person on the slick-rock trail in Moab. A highlight for sure.

 

[ClintR2]

Yes we are pretty excited about the gambler!!

So I got the timing set at 10degrees. Running at 1200 Rpms. Not sure why it is running that high??
Still doing the same t

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hing.
Tried to check all vacuum lines. Could not really find anything , but then again I might might’ve been doing it right.

I did find where a vacuum hose went. Any idea what this goes to? Might be the culprit.

 

[xmindbender]

you will know once you cap it. What is the vacuum at idle? they can be tough to track down.

 

[kc15842]

There should be a vacuum line route diagram on the hood. I think this line goes to an orange check valve and then to the 3 way vacuum fitting connected to the plenum.

 

[Dropzone]

Did you ever do a compression check?
What were the numbers?

 

[ClintR2]

Compression numbers below
1.171
2.173
3.177
4.173
5.175
6.175

Numbers look ok to me. Nothing to crazy low.

I put my finger on the vacuum line and no change.

I am puzzled.

Any ideas???

 

[kc15842]

Compression looks excellent. Did you fix the vacuum leak?

 

[ClintR2]

No I did not fix it yet.
Need to figure out where it goes.
Did not make a difference when I put my finger on it while running.

I am thinking maybe egr valve needs to be cleaned?
What do you think about inspecting it?