1990 throttle body
01-01-2021, 08:55 PM
#1
1990 throttle body
Hello, I currently own a 1995 3VZE 4Runner with a few issues on acceleration. I suspect my throttle body IAC to be the issue but not entirely sure. I have a brand new 1990 throttle body off a different 3VZE but noticed there are some differences between the two. Can I simply install the 1990 throttle body onto my 1995 4Runner? I also converted my 95 into a manual via the R150F transmission and am aware that the throttle bodies are different. The 1990 throttle body came off a manual 4Runner. Thank you for reading!
very respectfully,
-Dave
very respectfully,
-Dave
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spraypainthero (03-16-2021)
01-02-2021, 05:05 PM
#2
Registered User
Have you tried cleaning your IACV, and the coolant hoses going through the throttle body?
Those cooling hoses have a very tiny diameter the coolant flows through and plug very easy. I believe there is a little wax pellet in the IACV that the coolant temperature controls. When clogged it will cause a surging idle, possible other causes too.
Once you verify the coolant hoses are not clogged and you can blow through them easy, take off throttle body and there 4 phillips screws that hold a plate on the throttle body. Take that off and clean the crap outta it. (clean passages in the throttle body bore itself too)
Once cleaned you can get a smaller screw driver and actually push the valve it and see if it feels like it has tension and returns.
I should probably mention too, when I had acceleration issues on my 89’ 3vze pickup, it was my throttle position sensor. It would hesitate at lower rpm’s. When your TB is off, might be worth checking your TPS adjustment and see if it’s even within spec
Those cooling hoses have a very tiny diameter the coolant flows through and plug very easy. I believe there is a little wax pellet in the IACV that the coolant temperature controls. When clogged it will cause a surging idle, possible other causes too.
Once you verify the coolant hoses are not clogged and you can blow through them easy, take off throttle body and there 4 phillips screws that hold a plate on the throttle body. Take that off and clean the crap outta it. (clean passages in the throttle body bore itself too)
Once cleaned you can get a smaller screw driver and actually push the valve it and see if it feels like it has tension and returns.
I should probably mention too, when I had acceleration issues on my 89’ 3vze pickup, it was my throttle position sensor. It would hesitate at lower rpm’s. When your TB is off, might be worth checking your TPS adjustment and see if it’s even within spec
Last edited by maxvp01; 01-02-2021 at 05:07 PM.
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spraypainthero (03-16-2021)
03-16-2021, 04:46 PM
#3
same
Have you tried cleaning your IACV, and the coolant hoses going through the throttle body?
Those cooling hoses have a very tiny diameter the coolant flows through and plug very easy. I believe there is a little wax pellet in the IACV that the coolant temperature controls. When clogged it will cause a surging idle, possible other causes too.
Once you verify the coolant hoses are not clogged and you can blow through them easy, take off throttle body and there 4 phillips screws that hold a plate on the throttle body. Take that off and clean the crap outta it. (clean passages in the throttle body bore itself too)
Once cleaned you can get a smaller screw driver and actually push the valve it and see if it feels like it has tension and returns.
I should probably mention too, when I had acceleration issues on my 89’ 3vze pickup, it was my throttle position sensor. It would hesitate at lower rpm’s. When your TB is off, might be worth checking your TPS adjustment and see if it’s even within spec
Those cooling hoses have a very tiny diameter the coolant flows through and plug very easy. I believe there is a little wax pellet in the IACV that the coolant temperature controls. When clogged it will cause a surging idle, possible other causes too.
Once you verify the coolant hoses are not clogged and you can blow through them easy, take off throttle body and there 4 phillips screws that hold a plate on the throttle body. Take that off and clean the crap outta it. (clean passages in the throttle body bore itself too)
Once cleaned you can get a smaller screw driver and actually push the valve it and see if it feels like it has tension and returns.
I should probably mention too, when I had acceleration issues on my 89’ 3vze pickup, it was my throttle position sensor. It would hesitate at lower rpm’s. When your TB is off, might be worth checking your TPS adjustment and see if it’s even within spec
03-19-2021, 12:17 AM
#4
I cleaned the crap out of the throttle body, that intake air control valve? (IACV) was stuck and the coolant passages were full of rust and gunk. I guess there's supposed to be a wax pellet in the IACV? I pretty much put everything back on the way I took it apart, making sure not to turn the IACV spring cap all the way in. Got everything back together, burping the coolant system is a bitch? had to lift the front end, fill the overflow tank way past full mark, fill the radiator, put on the radiator cap not all the way on but not loose, start it up with the both heaters running and pinching the top coolant hose. Watching the cooling system suck the overflow tank dry and getting all the air pockets out of my coolant system was a relief.... cracked a beer at that moment and saw my idle my sitting at 900-1000 rpms. Not exactly what I was hoping for but I'll take that over 1500 rpm and when I was running errands today it was running super smooth no bucking or loss of power.
03-19-2021, 12:24 PM
#5
Registered User
That's the way I burp the system, when I replace the coolant every other year, or every year if I feel it needs it. I replace the 3 main radiator hoses at the same time.
After you drive it a while, especially if you can park it on an uphill a few times, don't just rely on the recovery tank to tell the tale. Once it's cooled down, open the radiator cap to verify the radiator is full. It should be, but it's good to be certain. A quick check, if you want it, is to squeeze the upper radiator hose. If there's air in there, it'll squeeze pretty easy, and you'll more than likely hear gurgling from the radiator.
The idle should be about 800 RPM. If it's too high, the idle will surge when you're stepping on the brakes. There's a "fuel cut" circuit in the ECM. Toyota decided you don't need the engine going any faster than idle if you're on the brakes. You must be stopping. So, if the engine RPM is above "idle", or over about 1100 RPM, and you step on the brakes, the ECM shuts the injectors off until the engine is below the max RPM, then allows them back on again. If the idle climbs above the max, the ECM shuts off the injectors, the RPMs drop, etc etc.
Be a good idea, now that things are working right again, to set the idle down to about 800.
I you have time, check the timing once you do, too. Who knows what it might be.
If you never have, you might want to pull the idle adjust screw out and check it's o-ring. They get old and brittle over time. They can crack, or just go to pieces. Cheap and easy fix to what is a mystery problem for a lot of troubles. Just make sure, before you take it out, you screw it all the way to where it touches bottom, counting turns, and parts of turns, all the way. Then, when you get the new one in, you at least have a starting point of where to set the screw to start out adjusting it. Make certain, once it's out, there's nothing clogging, or partly obstructing, the air passage it controls. A quick shot of carb cleaner, just a little bit, can do wonders.
Last, but not least, when you put the new o-ring on the screw, wipe it with a thin layer of Vaseline or silicon dielectric grease. It will help it last a LOT longer, and seal up better. Any rubber parts. O-rings, small hoses, door seals, anything. It really helps.
Glad you've got it going, though. Have fun in it!
Pat☺
After you drive it a while, especially if you can park it on an uphill a few times, don't just rely on the recovery tank to tell the tale. Once it's cooled down, open the radiator cap to verify the radiator is full. It should be, but it's good to be certain. A quick check, if you want it, is to squeeze the upper radiator hose. If there's air in there, it'll squeeze pretty easy, and you'll more than likely hear gurgling from the radiator.
The idle should be about 800 RPM. If it's too high, the idle will surge when you're stepping on the brakes. There's a "fuel cut" circuit in the ECM. Toyota decided you don't need the engine going any faster than idle if you're on the brakes. You must be stopping. So, if the engine RPM is above "idle", or over about 1100 RPM, and you step on the brakes, the ECM shuts the injectors off until the engine is below the max RPM, then allows them back on again. If the idle climbs above the max, the ECM shuts off the injectors, the RPMs drop, etc etc.
Be a good idea, now that things are working right again, to set the idle down to about 800.
I you have time, check the timing once you do, too. Who knows what it might be.
If you never have, you might want to pull the idle adjust screw out and check it's o-ring. They get old and brittle over time. They can crack, or just go to pieces. Cheap and easy fix to what is a mystery problem for a lot of troubles. Just make sure, before you take it out, you screw it all the way to where it touches bottom, counting turns, and parts of turns, all the way. Then, when you get the new one in, you at least have a starting point of where to set the screw to start out adjusting it. Make certain, once it's out, there's nothing clogging, or partly obstructing, the air passage it controls. A quick shot of carb cleaner, just a little bit, can do wonders.
Last, but not least, when you put the new o-ring on the screw, wipe it with a thin layer of Vaseline or silicon dielectric grease. It will help it last a LOT longer, and seal up better. Any rubber parts. O-rings, small hoses, door seals, anything. It really helps.
Glad you've got it going, though. Have fun in it!
Pat☺
The following users liked this post:
spraypainthero (03-20-2021)
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