TB and cold start........
07-01-07, 02:04 PM
#1
Turbo Waggin
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TB and cold start........
Has anyone ever had the problem of doing the TB mod, removing the thermal wax and having cold start issues? After i did this mod, my car is beast to start, it takes 4-5 long cranks to get her started. I'm wondering if this is because, with the secondary throttle plates wide open, is the engine getting too much air? aka not enough fuel? Also, assuming that the diaphragm is busted, which i'm sure its safe to assume, wouldn't that have created the same conditions all along, which would disprove my thoughts on the cold start issue. Either way, i'm tired of the cold start not working, and the car dying without throttle for the first minute, so i'm reinstalling the thermal wax and outboard throttle plates. ALSO, i've read quite a few threads on this, and HAILERS has very patiently described the double throttle system many times, but what i haven't yet discovered, is the specifics on how to test the diaphragm. Meaning, which nipple needs to be being sucked ( vacuumed ) ? and EXACTLY what does the delay valve do? when i blow through it it just seems "hard " to blow through. MY car is and AUTO/ 5spd swap, and i know the setup is a bit different, but exactly how?
1- can the car be fuel starved by to much air if Double throttles are perm open?
2-which nipple on the diaphragm needs vac to test it? and how do i know if its broken, and is it worth buying a new one?
3-what does the delay valve do? aka, a check valve in "one way" so is the delay valve "restricted"
4- auto vs m/t thermal wax vac differences?
THANKS!
1- can the car be fuel starved by to much air if Double throttles are perm open?
2-which nipple on the diaphragm needs vac to test it? and how do i know if its broken, and is it worth buying a new one?
3-what does the delay valve do? aka, a check valve in "one way" so is the delay valve "restricted"
4- auto vs m/t thermal wax vac differences?
THANKS!
07-01-07, 02:46 PM
#2
HAILERS
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1. No it should not.
2. ONly one nipple on the double throttle diaphram.
3. When cold, it helps hold a vacuum on the double throttle diaphram especially when the throttle is being open/shut durning normal driving prior to the water getting warm/hot.
4. There's a water thermo valve that controls the vacuum to the double throttle diapharam, BUT what your really looking for is the water thermowax and THAT is almost not visible on a non turbo car. Best I can say is to look at the fuel section of the manual for the location of it. I had heck finding it the first time I looked for one on my non turbo 87 car. I found I eventually had to remove the throttle body to adjust it. Others don't have to. They're better than I at that.
2. ONly one nipple on the double throttle diaphram.
3. When cold, it helps hold a vacuum on the double throttle diaphram especially when the throttle is being open/shut durning normal driving prior to the water getting warm/hot.
4. There's a water thermo valve that controls the vacuum to the double throttle diapharam, BUT what your really looking for is the water thermowax and THAT is almost not visible on a non turbo car. Best I can say is to look at the fuel section of the manual for the location of it. I had heck finding it the first time I looked for one on my non turbo 87 car. I found I eventually had to remove the throttle body to adjust it. Others don't have to. They're better than I at that.
07-01-07, 03:00 PM
#3
Turbo Waggin
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1. No it should not.
2. ONly one nipple on the double throttle diaphram.
3. When cold, it helps hold a vacuum on the double throttle diaphram especially when the throttle is being open/shut durning normal driving prior to the water getting warm/hot.
4. There's a water thermo valve that controls the vacuum to the double throttle diapharam, BUT what your really looking for is the water thermowax and THAT is almost not visible on a non turbo car. Best I can say is to look at the fuel section of the manual for the location of it. I had heck finding it the first time I looked for one on my non turbo 87 car. I found I eventually had to remove the throttle body to adjust it. Others don't have to. They're better than I at that.
2. ONly one nipple on the double throttle diaphram.
3. When cold, it helps hold a vacuum on the double throttle diaphram especially when the throttle is being open/shut durning normal driving prior to the water getting warm/hot.
4. There's a water thermo valve that controls the vacuum to the double throttle diapharam, BUT what your really looking for is the water thermowax and THAT is almost not visible on a non turbo car. Best I can say is to look at the fuel section of the manual for the location of it. I had heck finding it the first time I looked for one on my non turbo 87 car. I found I eventually had to remove the throttle body to adjust it. Others don't have to. They're better than I at that.
3- see photo.... since mine has 2, and im unsure which needs vac, then what does the delay valve do now?
4-ive got my uim sitting on my workbench, can you describe where that thermowax is located? is is outside the TB or inside?
07-01-07, 03:13 PM
#4
Turbo Waggin
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also, SEE PHOTO..... circled in the photo is the external part of the secondary throttle plate shaft.... i re-installed it, but should there be spring on that shaft? it just looks too clean! haha
07-01-07, 04:02 PM
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HAILERS
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Thermowax is on the firewall side of the engine. Take a picture and I'll show you.
Ugggggh. Two vacuum hose on the double throttle diaphram. God. Are you going to make me read a series five fsm. Ahhhhhh poooooooooooooo. Maybe a hour or two later from now. I'm a series four person and have to read the fsm for series five STUFF that is different.
Take the picture of the rear of the throttle body though.
Ugggggh. Two vacuum hose on the double throttle diaphram. God. Are you going to make me read a series five fsm. Ahhhhhh poooooooooooooo. Maybe a hour or two later from now. I'm a series four person and have to read the fsm for series five STUFF that is different.
Take the picture of the rear of the throttle body though.
07-02-07, 08:23 AM
#7
you should be able to remove the 3rd set of plates (TB mod) and keep the thermowax and still have cold idle
at least thats what i did on my old s4 n/a, but i cant remember what i did with those lines coming out of the thermowax. it looks like they are connected together when the thermowax is closed, opening the 3rd plate actuator. I think you can leave them uncapped
at least thats what i did on my old s4 n/a, but i cant remember what i did with those lines coming out of the thermowax. it looks like they are connected together when the thermowax is closed, opening the 3rd plate actuator. I think you can leave them uncapped
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07-03-07, 03:08 PM
#8
Turbo Waggin
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Now im having a whole new set of issues, i don't know if the hot days have anything to do with it, but my car has never had and overheating issues, its always sat at the bottom line and never went past 1/4 heat. Now its acting really weird, almost like its matching the tach... when i gas it the heat goes up, and when i let off it goes down..... and its reaction time ( the gauge) is QUICK... in the past its been slower to change according to conditions... could a new sensor have made it more accurate or sensitive? i replaced the old one the other day. And also, side note........... now ive got the fabulous 3800 and 6800 hesitations. great.
07-03-07, 04:37 PM
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That's the water thermo valve, if I remember right.
The water thermowax is ....below your red circle. And to the right. It's silver and there is a screw touching it. That screw has a spring under its head.
Sorry, I can't alter pictures from where I am right now. Later.
Anyway, it's the water thermowax that controls the high idle after doing a cold start or if the water has cooled down since the last start. That screw in the picuture with its head pointing down, plus another screw I can't see in that picture, determine the idle speed after doing a cold start.
Make another picture from the aft side of the throttle body. ONe from the side where the black vacuum hose are is what I mean.
OH. About a picute you posted with a bare space on a shaft where you thought a spring might go..........no, nothing goes there.
07-03-07, 06:35 PM
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Turbo Waggin
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That's the water thermo valve, if I remember right.
The water thermowax is ....below your red circle. And to the right. It's silver and there is a screw touching it. That screw has a spring under its head.
Sorry, I can't alter pictures from where I am right now. Later.
Anyway, it's the water thermowax that controls the high idle after doing a cold start or if the water has cooled down since the last start. That screw in the picuture with its head pointing down, plus another screw I can't see in that picture, determine the idle speed after doing a cold start.
Make another picture from the aft side of the throttle body. ONe from the side where the black vacuum hose are is what I mean.
OH. About a picute you posted with a bare space on a shaft where you thought a spring might go..........no, nothing goes there.
The water thermowax is ....below your red circle. And to the right. It's silver and there is a screw touching it. That screw has a spring under its head.
Sorry, I can't alter pictures from where I am right now. Later.
Anyway, it's the water thermowax that controls the high idle after doing a cold start or if the water has cooled down since the last start. That screw in the picuture with its head pointing down, plus another screw I can't see in that picture, determine the idle speed after doing a cold start.
Make another picture from the aft side of the throttle body. ONe from the side where the black vacuum hose are is what I mean.
OH. About a picute you posted with a bare space on a shaft where you thought a spring might go..........no, nothing goes there.
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