efi High Idle At Normal Operating Temperature

[ck_74tii]

Carl - thats a great pic exactly what i wanted to see. I will get that larger left-right 'breather' hose and connect it. See if that helps. Do you know if I need to replace the gaskets on the intake manifold if i remove pipe #3 and maybe #4 (as shown in the pic) or can i safely use the already installed manifold gasket?

 

Byas - Thanks so much for clarifyign whats going on wuth the vacuum lines and the valve. I will certainly try your suggestion of lubricating the valve above air filter. There is a large diameter vaccum line from the rear of the manifold that has another valve on it and then it continues to a cylindrical unit below the air filter. can you enlighten what thats all about

 

I am thinking of replacing all the vaccum lines. What are the two different vaccum line hose diameters? Can I simply get the vaccum lines at local parts store? (the large ones on my still has cloth around it - i assume it is original).

 

Thanks again so much.

Cheenu

[bnam]

That line is for brake booster -- it uses the manifold vacuum to help assist with braking.  The valve is a one way check valve -- it allows air to be sucked out of the booster, but will not allow air to be sucked into the booster -- so helps with maintaining the vacuum in the booster if the engine were to cut out to be turned off.

 

YOu can take a hose as a sample to see if you can match up.  If you are trying to keep it original, try one of the BMW suppliers.  I bough mine from 2002Haus.  Blunt, Maximilian, Penske, or even the dealer etc are other sources.

Edited January 30, 2014 by bnam

[PaulTWinterton]

ck_74tii,

 

Don't let the non-tii owner(s) get you down.  You'll experience a lot of satisfaction when you have a nice running car and the knowledge that only a handful of people in the world possess.

 

It's not magic, just a bunch of details that need to be addressed.  These includes air, fuel, vacuum, electrical, and mechanical components.  Once you have ALL those adjusted and working in sync your car will thank you with hours of driving enjoyment.

 

PLUS, it's a tii!

 

Have fun.

[eurotrash]

nevermind

Edited January 31, 2014 by eurotrash

[ck_74tii]

pulled out the old vaccum hoses today and got new replacements. I plan to replace them all tomorrow. I noticed there is a lot of  black residue in throttle body past the butterfly. can i simply pry it open and wipe it off with brake cleaner or do you recomment i take out the throttel body. I woudl prefer not to mess with the setting of the throttle bosy in case I do not do it correctly.

[eurotrash]

Yes.  clean it with carb cleaner.  It can alter your idle by restricting air flow.  Same with any modern car.  Should be the first thing any service center does at 'tune up'.
 

Edited February 1, 2014 by eurotrash

[ck_74tii]

Thanks for all the posts on these topics. Here is what I did over the weekend and the outcome.

 

I replaced all of the vaccum lines, including the large size vacuum line from the brake booster and the large (but different) size vacuum line from the front of the intake manifold to the valve on top of the air filter housing. I even retrieve the cracked breather hose (left-right) from the top of crank case to the air filter housing, fixed the crack and plugged in the small hose stemming from the throttle body (per Carl's recommendation). I pulled out the valve on top of the air filter housing, cleaned it with carb cleaner, and sprayed some teflon lubricant on the spring (per Byan's recommendation). I was not sure about just spraying away carb cleaner inside the throttle and into the intake manifold. Therefore, I cleaned the throttle body while it was attached with cloth dipped in carb cleaner.

 

After I put it all back, I started the car and after some initial roughness it settled back to a high rev at about 1800 rpm. I pulled hose form front of manifold into the valve on top of the air filter housing and felt it pull vacuum when I stuck my thumb and sealed it, the engine rev went back down, reattach it to the vbalve and it shot back up. So the valve is clearly letting air into the manifold.

 

I plugged the hose from the front of the manifold and the rear of the valve. The car started after that and this morning and seems to run fairly smoothly after warm up (felt the car was going to die out in idle when cold). It is running at 1100 rpm now - not too bad I think.

 

Is there anything else i can do to evive the valve on top of the air filter housing.

 

What are my next step, if any, or shoudl I be pleased ith it now. I have pleantly of othjer things to tackle susch as screeming belts (at 3500 rpm) and fuel filter and wire mesh clean up.

 

Is there a good link on how best to clean the wire meshes. I want to overhaul the fuel lines next.  

 

Thanks again - Cheenu

[OriginalOwner]

+1 PaulWinterton.

 

1100 rpm ain't bad, mine's about 900 and doesn't want to go any lower.  Inside the tuna can you can tweak that little screw thingie but that may not solve the "problem/concern" and may cause something new.  I would recommend just driving it around and get a feel for how the engine acts when being driven at-temp and at-speed.

 

On my car, I can change idle speed by opening the points gap a little bit.  Sometimes cleaning the spark plugs makes it idle faster, and sometimes slower.  Bigger gap on the spark plugs sometimes changes idle.  As I mentioned earlier, sometimes the engine responds to the color of my socks ..... 

 

I'm not at all familiar with that valve on top of the air cleaner, I've never ever done anything to it.

 

The various wire mesh strainers in the fuel delivery circuit are easy to clean:  take 'em out, blow 'em out, reinstall.

--  There is supposed to be a mesh strainer inside the inlet pipe to the electric fuel pump.  

--  Open the trunk, remove the right-side horizontal cover over the gas tank.  Then unhook the fuel hoses and GENTLY turn, then lift out, that gas gauge assembly.  There is a Delicate filter on the bottom of the gas intake tube, Gently clean that filter.

--  There is a wire mesh strainer inside the banjo fitting on the inlet/front of the Kugelfisher injection pump.

--  I think there is a wire mesh strainer inside the fitting on the outlet/back of the Kugelfisher injection pump ??

--  The in-line fuel filter that is mounted to the front firewall on the left side of the radiator:  replace it.

 

Any idea how old the rubber fuel hoses are ??  There's a lot of 'em:  gas tank to electric fuel pump, a short piece on the fuel pump, then from the pump to the engine, the piece up to the cold start valve, then fuel hose from the back of the injection pump to the rear firewall.  Any of those can leak and they will quite spectacularly, since they are under pressure.

 

--  BE AWARE:  all the fuel hose from the fuel pump outlet forward must be high-pressure hose due to the fuel pump outlet pressure.  Do Not Skimp and think you can get away with "normal" hose.

--  Also, those hoses that are currently installed:  hopefully you can verify that those hoses are indeed high-pressure rated.  To you it's a new car, you don't know what the previous owner installed.  Be certain.

--  Suction from the gas tank into the fuel pump:  "normal" low pressure hose is OK.

 

 

Cheers,

 

Carl

[bnam]

So the vacuum retard valve seems to be stuck open.  See if it holds a vacuum at the rear small inlet.  If it does not, the valve is toast.  If it does hold vacuum, but the diaphragm is just stuck -- perhaps adding a bit more vacuum or perhaps "pushing" it with some air pressure instead may help unstick it.

 

BTW, if the diaphragm has a hole in it, and it does not hold a vacuum -- it may be even letting in air thru the small hose into the manifold.  So, you will need to plug off that end of the valve as well and run the small vacuum hose from the manifold directly to the vacuum can on the distributor.  While you are it, see if the distributor can is holding vacuum.  If not, you have another source of leak.  In this case, plug the small hose on the manifold, and time the distributor like one from a 73-earlier Tii (centrifugal advance only).

 

Byas

[OriginalOwner]

 Recall I was earlier talking about the color of my socks in relation to idle speed ??  I just got back from a run to the grocery store.  Engine at normal op temp, etc etc ....  Idle speed about 400 rpm.  For the last few months it was doing just fine at ~900.

 

Cheers,

 

Carl

Edited February 4, 2014 by OriginalOwner

[PaulTWinterton]

OriginalOwner,

 

First thought, it sounds like a disconnected/defective air hose.  Too much air.

[bnam]

+1 - check the hose from the warm up reg to the manifold.

[jgerock]

Thanks for all the posts on these topics. Here is what I did over the weekend and the outcome.

 

 I was not sure about just spraying away carb cleaner inside the throttle and into the intake manifold. Therefore, I cleaned the throttle body while it was attached with cloth dipped in carb cleaner.

 

 

Thanks again - Cheenu

 

I was surprised how gummed up the throttle body was on my 73.  I first cleaned it from the outside, then removed it to see just how bad it is after the butterfly plate.

Before pictures (taken after removing the throttle body)

After

This shot is from the outside looking into the throttle body. New cold start valve installed.

 

An ultrasonic jewelry cleaner is your friend when you have a tii.

[ck_74tii]

I have riden it now for a couple of days and the car seems to hold 1100 rpm at normal operating temperature; though it seems to go to very low rpm at idle when cold. I am goign to ride it like this for a week to see it it holds.

 

Byas - with regards to the comment on the vaccum valve on top pf the air filte housing; how do i check if the small inlet is holding vaccum and again how do i check if the distributor can is holding vacuum? Also, do you thinking soaking it in gasoline will help clear some of the debris and respray with teflen? Is there a mwthod to apply a vaccum guage to the valve to verify functionality?

 

Carl - thansk for the pointer on fuel filter and meshes. the one in the engine bay looks respectable. The one line that I see is old and needs replacing is the one that feeds the fuel filter. I still have the hard plastic tubes from the KF pump to the injectors - are these worth replacing or should i leave them alone considerign things are fairly stable now with my engine.

 

Jgerock - wow that is one clean lookign throtle body. i am envious. I was not brave enough to remove mine least i throw out the injector/idle setting. why in the manifold and throttle body so full of deposits on the tii. I assume they did not have PCV vales back then. They should help right?

 

Chenu

[OriginalOwner]

the hard plastic tubes:  I don't want to say they will last forever, but I still have the originals on mine and never give them a thought.

 

I did however replace the tube for cylinder #1 a few years ago only because the tube was vibrating against something else and a groove/thin wall was created in the plastic, so I replaced it because the groove was deep.  I even succumbed to a bit of paranoia and loosely covered/wrapped the tubes (in the area of cylinders 1 & 2) in a short piece of bicycle inner tube.

  So there's something to do on a regular basis:  keep an eye on the tubes and make sure they aren't rubbing against anything, you want to maintain the full tube wall thickness.

 

Cheers,

 

Carl

Edited February 5, 2014 by OriginalOwner