Any thoughts on tii adjustment?

[BillWilliams]

I am somewhat familiar with setting up tiis. I have set many up and also set up two A4s with little difficulty.

However, I can not get the 2000tii to idle below 1,300 rpms. It just cuts off and dies. It starts up fine, takes throttle ok and runs smoothly above 1,300 rpms.

The cheap CO meter I have reads a CO% of 3%-4%. When I bring the idle down with the idle screw, it falls on it face.

K-pump and distributor rebuilt, points set at correct dwell, blue coil (no ballast resistor), timing set at 25 degrees BTDC at 2400 rpms.

New fuel pump and filters.

New Bosch plugs set at whatever the spec should be.

I am a little befuddled at the moment. Help appreciated

[MatthewCervi]

Random thoughts...all of which seem unlikely:

- Use an external tach to verify dash gauge is accurate. If the tach worked last year I guess I'd doubt its the problem though.

- Swap in another pump to make sure there isn't something wrong with this one.

- Massive vacuum leak in the warm-up regulator or hose or in one of the plastic runners? Seems like the CO % wouldn't be spot-on in that case.

Does it make any difference if the engine is cold or warm?

[BillWilliams]

I used the tach on the timing light plus my "ear" is good within 100 rpms and the tach is ok

Changing out the pump while the motor is in the car is one of my worst nightmares . Done if before, will make this the last resort.

Used carb cleaner and found one vacumn leak from a cracked plastic tube. Switched that out for another old one. Checked for leaks around the tubes again, did not find any more leaks. Did not check around the warm up regulator though, I will check there next.

I runs fine while the car is still on the warm up cycle. When it comes off of warm up is when it falls on it face eg when the idle comes down

Thanks, Matthew!

[02fanatic]

Bill:

Does the throttle body "return spring" clear the fuel injection plastic lines...in other words, does it "not" hang up? Just a thought.

Also, I know you know how to test the cold start valve....but once the engine is warm, try unplugging the cold start valve and see if that makes a difference.

On the way home from Lime Rock several years back, my "Atlantik" tii would not idle back down...it was the cold start valve malfunctioning...I simply unplugged it and the idle came right down to about 950 to 1,000 rpm...that's where a tii is 'suppose" to idle at.

1,300 rpm is not that much above normal, so try the above....assuming the throttle body cam is adjusted properly, then you might have a slight vacuum leak somewhere...which I'm sure you've checked on already, but just another thought.

Does your throttle linkage have any "play" in it?...it needs to reset to idle without hanging up....Hugo's was hanging up on the pedal box at one point...make sure it's all clear down under there!

Another thought...the bracket that attaches to the block that connects to the throttle linkage is very easy to put on "backwards"....if this bracket isn't installed properly, the throttle linkage will "not" operate through the full range of motion...ask me how I know? :-) Hugo's was on backwards when I found him.....it was a real mystery until I looked at my other tii ("Atlantik") and noticed the difference.

Finally, if everything else looks to be in order, you might try retarding the ignition a hair...by turning the dizzy and timing "by ear"...very few tii engines will actually run "perfectly" when set to factory specs timing-wise.

I know you'll figure it out......I agree messing with the pump is the last resort...I wouldn't fool with it unless absolutely necessary! :-) You "did" set up the Kugelfischer pulley right with the timing mark pointing to the mark on the pump body right?...it's easy to be off one tooth!..that's easy to check by removing the plastic inspection cover on the Kugel. It should be lined up perfectly at TDC (#1)...another nice thing about tii's...everything lines up at TDC.

I don't know if I've been any help...but all those things come to mind.

Good Luck,

John

[MatthewCervi]

Hmm...if its fine until it is warm then I vote for either the warm-up regulator leaking or the vacuum hose between it and the air chamber. Good luck finding it!

[BillWilliams]

Thanks for the replies.

The problem is that I can not get it to idle when I bring the car down below 1,300 rpms using the idle screw.

It is not that it will not decrease in rpms which is the case with a leaking cold start valve but I did check that.

The linkages are not in play at all when I am trying to get it to idle but I did work on the improving the smoothness of the travel today. The rubber thing that goes behind the carpet was the main source of resistance. I cut a little of the rubber away that was in the way of the throttle pedal travel. I also re-lubricated the shaft.

I too suspect a small vacumn leak that is leaning the motor out at idle were the mixture is super critical.

Jonathan Maxson is coming up in the morning and if we can get the car stable again at 1,300 rpms, I will chase the vacumn leak idea.

Wish me the best!

Fixed the high beams today and Mike 'On Star' Pugh reminded me that the blinkers do not work unless the emergency switch is plugged in, which mine is not yet. I will check that tomorrow too.

[ray_]

I think it must be an air leak somewhere Bill. Good luck and keep us posted.

Cheers,

Ray

[BillWilliams]

(nt)