Throttle Body coolant block off?

[apex944]

Replacing my coils this weekend, and in the process of taking the manifold off I disconnected the throttle body coolant hose...
Which prompted the question... Is this really needed ? I see its a common failure point.

 

[4Runner]

Oh boy. Here we go. lol. I have one with it hooked up for decades. And one without. Both have been in all weather extremes, minus 15 to 110. I haven’t had any issues but that’s just my experience. If you did a search, there is a lot to be said on the matter.

 

[apex944]

I did do a search but busy with the coils so didnt dive too deep. Most seemed to be cooling related discussions.

BTW, the more common DIYs on the intake manifold removal make it soo much harder than it actually is. I may do a write up to add to the hundred others later

 

[rovercanus]

Not this again. On my 2000 I had it removed from the cooling circuit and had my T-body freeze up twice. This was low 20's with relatively high humidity.
It's really not a good feeling when your throttle doesn't respond.

 

[jymmiejamz]

I’ve had it freeze as well. High humidity but I think it was right around freezing temps.

 

[apex944]

OK even tho the truck sits in the winter I'll be putting it back on then.
Any reason the LRs do this? I've had a number of cars with almost an identical Intake & Bosch mgmt setup that never needed the TB warmed.

 

[kris812]

TB coolant is actually pretty common in the 90s cars for emissions and OBD2 standards. I've seen it on Fieros, firebird's, Oldsmobiles, and Ford's. I think some LR even have coolant cooled alternators.

Even though I'm in AZ with 120F summers and almost no freezing I keep them attached.

True on an old carbed engine it'll have more power with this defeated. However due to emissions control you'll probably have less power/fuel economy as the metered intake air temp would be different than actual intake temp. In theory it would richen the fuel beyond needed making less MPG. But once closed loop kicks in who knows the outcome.

 

[ukoffroad]

I always ditch it, but some folks here have had issues with it

 

[JUKE179r]

I bypassed mine by running the 1/2" (?) coolant hose from the top of the engine straight to the coolant reservoir.
No issues in Atlanta, Georgia with hot temps and humidity or here in England with colder weather.

 

[Sandyg]

I just replaced the coolant line from the tank to what I thought was the TB on mine. I looked at where the non-stock looking rubber 5/16" hose went and it looks like it was just connected to a union/splice to where it continues to the manifold behind the A/C compressor. At least the mechanic who did the hack was nice to split the line for easy access if needed where you could easily get to part of the hose. That is when I noticed that the stock line from British Atlantic said it went to the TB so I was just thinking the same thing about freezing up.

The car is going to Salt Lake City for my son in the winter, will see how it goes...

Good timing, fixed the leaking line just a couple of days ago and was going to ask here how important it might be.

Sandy

 

[best4x4]

#1 cause of a sticking TB = throttle body plate is dirty!!!! Not because the TBH was bypassed. I have seen 5 so called stuck throttle bodies so far, and each one was on a D2 or P38. They were still using the OEM baffle in the valve cover which was NEVER serviced vs my PCV Upgrade. I took each TB off, removed the 3 small screws securing the TB Plate to the TB. Cleaned it with a scotchbrite pad, and then used some fine steel wool on it. I also cleaned inside the TB housing itself to remove the line of crud which had built up over the years. Put it back together and the so called sticking TB was like new.

I don't have any pictures (will try to locate the worse one) but from what I've seen the excessive oil build up in the intake just literally coated the TB plate and housing with a layer of crud. I had one so bad it actually broke the TB cable itself.

A good friend of mine was heading on a trip from Texas to Canada and I went over her D2 before the trip. We were talking about the TBH plate and I noticed theirs was starting to get seepy. I told em the stories about the mythical stuck TB and it was pretty funny I went WOT by hand on their TB and it DID NOT go back to base idle position.... Removed the intake tube and all I saw was a nice layer of oily crud. OEM baffle in valve cover, and the TB had never been cleaned.. Installed PCV Upgrade, removed TB and cleaned it. Zero issues after and yes the TBH was bypassed. Trip from Texas to Canada = zero issues.

People these days seem to think just because the vehicle is fuel injected that you don't have to clean or service the TB at all & that is false.

 

[4Runner]

I bypassed mine by running the 1/2" (?) coolant hose from the top of the engine straight to the coolant reservoir.
No issues in Atlanta, Georgia with hot temps and humidity or here in England with colder weather.
View attachment 65284

How is the secondary air set up working for you? Have thought about getting rid of those hard lines for a while.

 

[JohnHZ3]

I installed this upgraded version a few years ago and so far so good. Not cheap but if it lasts it will be money well spent.
https://www.sportscarcentre.ca/MGM000010K

 

[JUKE179r]

How is the secondary air set up working for you? Have thought about getting rid of those hard lines for a while.

I replaced the hard-lined SAI piping at the rear of the engine with reinforced rubber tubing. I did this mod for easier removal if need be for engine maintenance.
No issues or trouble fault codes in the 2 years since I did this mod.

https://cimg4.ibsrv.net/gimg/landroverforums.com-vbulletin/2000x1333/80-80_97fee5df_e54f_4b9a_ac3f_7af813186de7_9af7df367510fdabd726ea56e2862f4c03e0dc56_jpeg_2ae775719fa467b4aa080ab132090054db0880ab.jpg