92 intake/theottle body swap in 1gen

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flash02

flash02

10 Year 15 Year
Joined
Sep 8, 2006
Threads
67
Messages
588
Location
Elizabeth City, NC
Just installed a 92 upper intake and throttle body in my 86 Runner, everything went well except the idle adjustment screw does not seem to do anything. The idle air control air control valve works well. Before anyone asks everything was cleaned and new gaskets used. I do know this setup came from an automatic truck, I'm thinking I may have to adjust the throttle stop. Thoughts....?

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make sure the throttle position sensor is to exact specs using a meter. if it is slightly off you won't be able to adjust much of anything. you may have done this already but since you didn't say i thought i would suggest it.
 
liveoak said:
make sure the throttle position sensor is to exact specs using a meter. if it is slightly off you won't be able to adjust much of anything. you may have done this already but since you didn't say i thought i would suggest it.
Click to expand...

Yeah I did adjust it, but......I'm going to recheck. Thanks for the suggestion, once off of higher idle it hovers around 1k RPMs and the idle adjust screw is almost seated.

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Problem fixed! I checked and adjusted the dash pot and throttle stop, then to adjusting the TPS, I found that the 0 clearances was spot on but when the thicker feeler gauge was installed my readings were NOT infinite as per the FSM. I've read that the only check that really matters is the closed throttle position, so I just left it at that, the truck runs great and I am now able to set the idle, Thank you all for the help.

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Just out of curiosity, were you following the instructions in an '86 applicable FSM or a '92 applicable?

I put a '94+/- upper plenum and TB on our '85 about 3 years and didn't do any adjusting and was thinking about going through the procedure in the '85 service manual but wanted to make sure that all was still applicable. I assume so but thought I would ask anyway.
 
WarDamnEagle said:
Just out of curiosity, were you following the instructions in an '86 applicable FSM or a '92 applicable?

I put a '94+/- upper plenum and TB on our '85 about 3 years and didn't do any adjusting and was thinking about going through the procedure in the '85 service manual but wanted to make sure that all was still applicable. I assume so but thought I would ask anyway.
Click to expand...

What I did was swap the TPS paw from the 86 throttle body to the 92 throttle body and then fit the 86 TPS. The TPS connector will not fit the newer TPS and I think there may be an ECU issue if you change out the plug and use the newer sensor with the older ECU. I followed the FSM for my year truck as far as TPS adjustment. One thing was that I spent about two hours cleaning the upper intake and throttle body, all from a 92 2WD auto truck.

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Ok so I just made a 1600 mile trip in my 4Runner, everything ran grate and I got 20 MPG, not too bad, problem is it idles like crap. I'm leaning towards a TPS as I've adjusted it but my idle still seems to want to drop way low sometimes it evens sticks around 1000. Just as a recap the following has been done to the engine.... Rebuilt with engbldr parts including his big valve head and higher lift cam, rebuilt injectors, swapped later throttle body from a 92' truck and installed a LCE throttle body spacer and intake system. I've followed the TPS adjustment procedures per the 86 FSM, oh and yes I did swap the TPS paw from my old TB to the new TB and reused my original TPS. Thoughts, tips, tricks??????

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flash02 said:
Ok so I just made a 1600 mile trip in my 4Runner, everything ran grate and I got 20 MPG, not too bad, problem is it idles like crap. I'm leaning towards a TPS as I've adjusted it but my idle still seems to want to drop way low sometimes it evens sticks around 1000. Just as a recap the following has been done to the engine.... Rebuilt with engbldr parts including his big valve head and higher lift cam, rebuilt injectors, swapped later throttle body from a 92' truck and installed a LCE throttle body spacer and intake system. I've followed the TPS adjustment procedures per the 86 FSM, oh and yes I did swap the TPS paw from my old TB to the new TB and reused my original TPS. Thoughts, tips, tricks??????

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Click to expand...

Sam thing is wrong with my 89 Toyota pickup and I got a thread u should look at. Everyone on here is tellin me it's my vaccum hoses. Might be clogged or even disconnected. Sometimes when my idle is bouncin up and down while I'm drivin it will take over my gas an make my whole truck start hoppin.
 
flash02 said:
... once off of higher idle it hovers around 1k RPMs and the idle adjust screw is almost seated.
Click to expand...

You have the function of the idle screw backwards. Turning it all the way in will lower the rpm. Turning the screw out will raise the rpm. Screw up, idle up. Screw down, idle down.
 
pappy said:
You have the function of the idle screw backwards. Turning it all the way in will lower the rpm. Turning the screw out will raise the rpm. Screw up, idle up. Screw down, idle down.
Click to expand...

Sorry that's what I meant, my fingers reversed it. It seems like I have to keep turning the idle screw out, counter clockwise, to keep the idle from falling to low. I have thought that it is vibrating out but the force required to turn it with a screwdriver seems to tight for engine vibrations to cause this, I put those stupid poly engine mounts in, so I'm not sure what is going on. Vacuums leaks, not sure....

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WarDamnEagle said:
Here's a link for you with some additional links that might be helpful. Did you disconnect the air flow valve? Just thinking outloud here.
Click to expand...

Heck, toss the air valve in the trash.
 
If you are referring the Aux Air Valve, then yes, no need to keep something that is no longer use. Today when I fired it up I adjusted the Engine speed to 1000RPM, when the engine came to temp it settled to about 800PRM and held. Perhaps the rubber O ring is worn thus allowing the screw to get out of adjustment from vibrations. Hell who knows, I can get a new adjuster for about $6.00 Crome LCE, worth a try.

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What did you do about the intake tube/hose? It is my understanding that you can't use your old one, the angle of the elbow at the throttle body is too far off.
 
KLF said:
What did you do about the intake tube/hose? It is my understanding that you can't use your old one, the angle of the elbow at the throttle body is too far off.
Click to expand...

I went with the LCE intake set up, I think you can reuse the old crossover tube with the late style rubber connector. I was going to get some silicone intake hoses and make it work, even better would be to ditch the old restrictive crossover tube and have one made out of aluminum, larger of course, (2.5") then get the appropriate silicone connectors. The LCE setup is ok, bit expensive, personally if I hade to do it over I would have hade a crossover tube custom made, the LCE set up is a bit tight and heavy and if used with the throttle body spacer requires some work. The best upgrade would be to use the late TB and upper intake, have it bored by max bore, then upgrade the crossover tube to 2.5", personally I don't think the LCE K&N cone filter adapter is worth the money, switch to the bigger air flow meter with a cone filter. Here is another thing to think of, the late style TB gets very hot sine coolant is always running to the Air Valve, on the early TB with the electric Aux Air Valve an easy mod can be accomplished to bypass the coolant going to the TB thus keeping is cooler, cooler denser air gives more power. I guess what I'm getting at is if your old electric Aux Air Valve works I don't see the benefits of going to the later TB especially when you figure in the cost of gaskets, throttle cable, TB and upper intake, plus the time involved in removal, cleaning and install.

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flash02 said:
What I did was swap the TPS paw from the 86 throttle body to the 92 throttle body and then fit the 86 TPS. The TPS connector will not fit the newer TPS and I think there may be an ECU issue if you change out the plug and use the newer sensor with the older ECU. I followed the FSM for my year truck as far as TPS adjustment. One thing was that I spent about two hours cleaning the upper intake and throttle body, all from a 92 2WD auto truck.

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Click to expand...

Can anybody confirm if there are ECU issues using the later model TPS on the 86 with a throttle body swap? I changed the plug and used the new sensor and i have shifting issues..short second gear and shifting back from 4th to 3rd..see,s like its not ready for 4th and shifts back to 3rd. Should i put back original TPS?
 
MILOWILLI said:
Can anybody confirm if there are ECU issues using the later model TPS on the 86 with a throttle body swap? I changed the plug and used the new sensor and i have shifting issues..short second gear and shifting back from 4th to 3rd..see,s like its not ready for 4th and shifts back to 3rd. Should i put back original TPS?
Click to expand...

There should not be any issues what so ever, it sounds like your TPS is out of adjustment. When I did this conversion I used the original TPS, in order to use the early TPS on a late throttle body you must transfer the paw that moves the TPS from the old throttle body to the new throttle body then adjust the TPS per the FSM.
 
KLF said:
What did you do about the intake tube/hose? It is my understanding that you can't use your old one, the angle of the elbow at the throttle body is too far off.
Click to expand...

I used the intake tube from the 94 engine when I did my swap. I think I only used the flexible portion but I can't remember exactly. Whatever I did, I remember that it required no modifications.
 
WarDamnEagle said:
I used the intake tube from the 94 engine when I did my swap. I think I only used the flexible portion but I can't remember exactly. Whatever I did, I remember that it required no modifications.
Click to expand...

Thanks. I was able to find an entire later intake tube locally, so I think I'm all set.

FYI: I am swapping an '89 intake onto my '87. It has the "straight" plenum and the different plumbing of the air valve. But, the TPS is exactly the same as my '87, same part number stamped on it. When I pulled the TPS off both throttle bodies, the pawl was exactly the same. So I don't have to swap the pawl over. Not sure when they changed, I suppose you could figure it out with the EPC.
 
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