T-VIS

Timon · 11-20-2008, 07:39 PM

I'm wondering if there's a way to test the T-VIS in an '87 MR2. The reason I'm asking is because there was normally an exhaust note when the T-VIS opened up, but that seems to have gone away.

How would I test to make sure the T-VIS is in operating condition, and if it isn't, what could be stopping it from opening?

Luni · 11-20-2008, 08:50 PM

BGB says to test TVIS connect a vacuum gauge to the nipple that feeds the TVIS butterflies. It says you should have vacuum on the gauge below the set point which is like 4200 rpm (not sure if its the same on a MK1), and then 0 vacuum after the set point.

Timon · 11-20-2008, 09:38 PM

I was able to find this diagram of the vacuum lines.

I assume I'd disconnect and test the hose coming off the VSV - does that sound right? Else would I test the hose coming off the diaphragm?

Luni · 11-21-2008, 02:06 AM

I think you could just test it like you said. The hose off the VSV that goes to the diaphgram.

Teado · 11-21-2008, 11:59 AM

When I took mine apart, it was pretty gummy, from all the emission crap (EGR valve) feeding back into the top of the T-VIS. Not to mention it's vacuum actuated, so if there's much stick there, it would be hard for the vacuum to overcome it.

Timon · 11-21-2008, 11:54 PM

Wow, I'm assuming mine looks similar to that. How did you pull it all apart? Anything to watch out for if I do it, or cleaners to use on it?

novatc · 11-22-2008, 12:31 PM

timon, i just did a head gasket on my 86 mk1. The tvis butterflys sit between the intake manifold and the cylinder head. just remove the intake, and the tvis will come rite out(thats easier said than done, mine came off after i got the head off.). the same bolts that attach the intake to the head go thru the tvis plate, its tricky getting this mess back together. A good hayes service manual will tell you everything about this car. It has detailed instructions on how to test the tvis.

11-20-2008, 07:39 PM	#1 (permalink)
Timon MR2 MKI AW11 Join Date: Feb 2008 Location: Utah Posts: 430 Thanks: 4 Thanked 27 Times in 23 Posts My Google Map iTrader Rating: (0/0% )	T-VIS I'm wondering if there's a way to test the T-VIS in an '87 MR2. The reason I'm asking is because there was normally an exhaust note when the T-VIS opened up, but that seems to have gone away. How would I test to make sure the T-VIS is in operating condition, and if it isn't, what could be stopping it from opening? Last edited by Timon; 11-20-2008 at 08:18 PM.

11-22-2008, 12:31 PM	#7 (permalink)
novatc No Skills Join Date: Dec 2006 Posts: 46 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	tvis system timon, i just did a head gasket on my 86 mk1. The tvis butterflys sit between the intake manifold and the cylinder head. just remove the intake, and the tvis will come rite out(thats easier said than done, mine came off after i got the head off.). the same bolts that attach the intake to the head go thru the tvis plate, its tricky getting this mess back together. A good hayes service manual will tell you everything about this car. It has detailed instructions on how to test the tvis.

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11-20-2008, 08:50 PM	#2 (permalink)
Luni ST185 Powered SW20 Join Date: Oct 2005 Location: Salt Lake City Utah Posts: 2,740 Thanks: 7 Thanked 95 Times in 81 Posts My Google Map iTrader Rating: (8/100% )	BGB says to test TVIS connect a vacuum gauge to the nipple that feeds the TVIS butterflies. It says you should have vacuum on the gauge below the set point which is like 4200 rpm (not sure if its the same on a MK1), and then 0 vacuum after the set point.

11-20-2008, 09:38 PM	#3 (permalink)
Timon MR2 MKI AW11 Join Date: Feb 2008 Location: Utah Posts: 430 Thanks: 4 Thanked 27 Times in 23 Posts My Google Map iTrader Rating: (0/0% )	I was able to find this diagram of the vacuum lines. I assume I'd disconnect and test the hose coming off the VSV - does that sound right? Else would I test the hose coming off the diaphragm?

11-21-2008, 02:06 AM	#4 (permalink)
Luni ST185 Powered SW20 Join Date: Oct 2005 Location: Salt Lake City Utah Posts: 2,740 Thanks: 7 Thanked 95 Times in 81 Posts My Google Map iTrader Rating: (8/100% )	I think you could just test it like you said. The hose off the VSV that goes to the diaphgram.

11-21-2008, 11:59 AM	#5 (permalink)
Teado MK1 = My Daily Addiction Join Date: Jun 2008 Location: Oregon Posts: 133 Thanks: 7 Thanked 8 Times in 7 Posts iTrader Rating: (0/0% )	When I took mine apart, it was pretty gummy, from all the emission crap (EGR valve) feeding back into the top of the T-VIS. Not to mention it's vacuum actuated, so if there's much stick there, it would be hard for the vacuum to overcome it.

11-21-2008, 11:54 PM	#6 (permalink)
Timon MR2 MKI AW11 Join Date: Feb 2008 Location: Utah Posts: 430 Thanks: 4 Thanked 27 Times in 23 Posts My Google Map iTrader Rating: (0/0% )	Wow, I'm assuming mine looks similar to that. How did you pull it all apart? Anything to watch out for if I do it, or cleaners to use on it?