engine and drivetrain Tii Throttle Body Replacement

[RED1602]

How hard is it to replace the throttle Body in a 74 Tii? 

What is involved?

Any help or direction would be greatly appreciated.

Thanks

KM
1970 1602 W/s14 (M2) 
1974 2002 Tii (Show) 
1989 325ix (Winter) 
1991 325ic (Summer)
2008 128i (Daily)

[bnam]

Replace with another (new or better condition) Tii throttle body -- or replace with a non-Tii throttle body?

[RED1602]

Replace with another (new or better condition) Tii throttle body.

KM

1970 1602 W/s14 (M2) 
1974 2002 Tii (Show) 
1989 325ix (Winter) 
1991 325ic (Summer)
2008 128i (Daily)

[bnam]

Fairly easy.  You do need to have (buy or make) the tools need to synchronize the fuel injection pump to the throttle.  I made the tools for $5-10.

B

[thehackmechanic]

It's not difficult at all. Search here on the FAQ and you can find a photographed procedure, but from memory:

 

--Remove the air cleaner.

 

--Undo the hoses connected to the throttle body.

 

--Loosen the two 10mm pinch bolts on the collar on the shaft coming out of the throttle body.

 

--Remove the two 10mm bolts holding the side of the throttle body to the bracket.

 

--Remove the four 10mm nuts holding the throttle body to the intake manifold.

 

--Lift the throttle body and the shaft coming out from beneath it as a set. The shaft should slide out of the collar with the pinch bolts, but you may need to hold the intermediate shaft (the one beneath the collar) down.

 

I think that's pretty much it. As Bnam said, you'll have to resync the fuel injection, since you will have loosened the pinch bolts, but that is well-documented on this site. Before you remove the TB, you might want to visually check where that half-moon cam is set relative to the alignment hole in the tuna can at the top of the TB. Again, search here; there are dozens of threads on this.

 

 

--Rob

[RED1602]

Thanks Rob and Bnam for the information but, getting the part out and the new one in is not the problem What scares me is the synchronizing the fuel injection pump to the throttle Body. I guess I'll do more search on that topic.

KM

1970 1602 W/s14 (M2) 
1974 2002 Tii (Show) 
1989 325ix (Winter) 
1991 325ic (Summer)
2008 128i (Daily)

[lilmo]

Don't forget the gasket between the TB and the plenum.  It's thin and fragile (if it's there at all).  

[PaulTWinterton]

FWIW...if your throttle shaft is not worn you can have a machinist replace the bushings in the throttle body at much less cost than a complete replacement.

There is also a plastic cap that covers the bottom outer pivot. You can find a replacement cap at your local hardware store. I believe this cap keeps out dirt and AIR.

 

[PaulTWinterton]

Ah yes, the art of syncronization.  A tii owners cross to bear.  Start by reading everything on the subject.  There really isn't any magic, just knowledge and experience.

 

I would recommend finding an experienced KF/Tii guy in your neighbourhood to coach you.  It will save you heaps of trial and error.

 

Good luck.

[RED1602]

Thanks Paul for the reply. I have all the parts but I just don't know how to do the synchronizing part. I have been searching but just can't find anything on it. I guess  I have to start with buying the tool.

As far as help goes, I live in SLC Utah and my Mechanic who use to work on it for 26 years died couple of years ago and the problem is there aren't any Mechanics here who know anything about these Tii's. I do my own work on all of my cars even did the M2 conversion but the Tii was his Baby so I never learned to worked on the injection system.

 

 

KM

1970 1602 W/s14 (M2) 
1974 2002 Tii (Show) 
1989 325ix (Winter) 
1991 325ic (Summer)
2008 128i (Daily)

Edited January 23, 2014 by RED1602

[RED1602]

Is there anyone in Salt lake who can help me with this synchronization.

Thanks

KM

1970 1602 W/s14 (M2) 
1974 2002 Tii (Show) 
1989 325ix (Winter) 
1991 325ic (Summer)
2008 128i (Daily)

[JohnS]

Download a .pdf of the fuel injection manual from here:

 

http://www.2002tii.org/kb/59

 

There's also a set of the tii specific tools for sale on e-bay right now.  I purchased a similar set from the same seller who is also a member of the FAQ:

 

http://www.ebay.com/itm/BMW-2002-2002tii-tii-special-tools-for-kugelfischer-pump-synchronization-/131097885537?pt=Vintage_Car_Truck_Parts_Accessories&hash=item1e860afb61&vxp=mtr#ht_330wt_1105

 

Good luck,

John

[thehackmechanic]

If all that you're doing is removing and reinstalling the TB, you can get it close with the following procedure:

 

--By searching here or downloading the manual from here (http://www.2002tii.org/pump/pump_guide_v1.pdf), understand what it means to "pin the pump." You don't need the special hook-shaped tool. An Allen key of the appropriate size will get it close enough.

 

--Understand what it means to look at the hole in the tuna can and where the half-moon cam crosses it.

 

--Then, pin the pump at the idle setting and take a photo of the half-moon camp across the hole in the tuna can.

 

--Then remove the throttle body.

 

--If you were simply removing and reinstalling the TB for, say, cleaning, you could put the TB back in, pin the pump, rotate the half-moon cam to EXACTLY the same place it was before, tighten the two pinch bolts, and the car should have about the same air/fuel synchronization as it did before, which isn't to say it was right or optimum before. Or you could do it as per the manual, which tells you to pin both the pump and the can (have the cam aligned at the edge of the hole).

 

--The problem is, life doesn't work that way. If it's a different throttle body, you'll need to adjust the idle mixture, which is done via the fine screw on the butterfly in the tuna can, and the idle speed, which is the big screw on the outside of the tuna can. You turn that little screw in to lean out the mixture. If you don't have a CO meter, you can use your ear, and it's generally pretty effective. At some point it'll be lean enough that the idle starts hunting. Back the screw out until it stops. That's pretty close.

 

--But getting all of this optimum as opposed to close really requires a portable exhaust gas analyzer so someone can see what the air/fuel is on the road, preferably at a range of loads including full throttle.

 

--Start by downloading and reading the manual in the link. It'll get you familiar with the concepts. It'll help you to decide whether to do it yourself, and help you to ask intelligent questions of repair shops.

 

 

Rob

 

 

[RED1602]

Thanks Rob, downloading the manual after this.

 

KM

1970 1602 W/s14 (M2) 
1974 2002 Tii (Show) 
1989 325ix (Winter) 
1991 325ic (Summer)
2008 128i (Daily)

[thehackmechanic]

What are the symptoms leading you toward replacing the TB?