Tii good cold start, terrible warm running - PROBLEM SOLVED!

[Swiss 2002Tii]

Yep, it's true Dave, I've been at this for a while (dinking between travel and other events)!  My linkage was seriously sloppy, so time to tighten it up!  That's why I want to get all of the right parts assembled and put it back together per spec... and then adjust it! ?

So did you lengthen the shaft, rather than adjust the verboten screw?

I'm pretty certain by now that anything I do with the stock alignment will continue to give a lean result, so once I get everything tight, I can start making adjustments.  If I can get it ready to run like it does when cold, I'll be a happy camper!

Tom

[irdave]

Hey Tom.

 

I put in a wide band o2 sensor a while ago- it's really just something you have to do.  Mine was pretty easy- couple hundred dollars for the part, exhaust came off pretty easy from underneath, drill a hole, weld in the bung, put it all together.  With that in mind, I've been messing with everything trying to find correlations so I know what adjusts which part...  My understanding from here and testing is as such; verboten screw is a global setting (I'm at 5,000 feet so my screw is backed way out), "D" cam tunes the initial (idle) mixture and has effect on the whole range, the intermediate shaft effects more the quarter to half throttle position...  Something like that.

 

I think something often overlooked is the opening pressure of the injectors.  If the springs are soft then the injectors are opening early and closing late, thus staying open too long...  There's a spring place in Denver that I need to get down to and see if they can make us new springs...

[PaulTWinterton]

1 hour ago, Swiss 2002Tii said:

I'm pretty certain by now that anything I do with the stock alignment will continue to give a lean result, so once I get everything tight, I can start making adjustments. 

 

You could be right.  Remember the first non-stock adjustment is to position the cam over the 4mm hole.  Sometimes that is enough.  I've seen happy engines with the cam at the edge of the hole, slightly covering the hole, and half covering the hole.  the more the hole is covered the more fuel over the entire range.  If you cannot achieve good results from that method then you mess with the verboten screw.

 

91mm.  Wow.

296mm.  Time to go back and read the posts about pedal positions at idle and WOT.  Someone may have changed the stop adjuster on the back of the KF to compensate for all the linkage adjustments.

 

Synopsis: It's good you are going through all the components and putting them back to spec.  You've had some extreme variations and combined, they can't be good.  Not so bad at idle, but compounded with any throttle increase.

 

I applaud your patience.

Edited July 1, 2018 by PaulTWinterton

[Swiss 2002Tii]

43 minutes ago, irdave said:

I put in a wide band o2 sensor a while ago- it's really just something you have to do.

I have been using the Innovative LM-2 with the exhaust venturi mount as I have two, soon three oldtimers that I've been checking.  I have the bung in hand to be installed in the downpipe when I get the Tii up on a rack to drop the tranny and replace a leaking front seal on a newly rebuilt Metric Mechanic 5-speed (Jim Rowe made good and sent me the seal and tool to install).  I'll likely mount the sensor I have in the Tii and get a replacement to use with the exhaust mount.

 

47 minutes ago, irdave said:

I think something often overlooked is the opening pressure of the injectors.  If the springs are soft then the injectors are opening early and closing late, thus staying open too long... 

I had the KF and injectors checked; three opened at a nominal 35 bar, one was a little lower at 32 bar, still within tolerance..

 

32 minutes ago, PaulTWinterton said:

91mm.  Wow.

296mm.  Time to go back and read the posts about pedal positions at idle and WOT.  Someone may have changed the stop adjuster on the back of the KF to compensate for all the linkage adjustments.

Unfortunately I'm missing the pedal stop on my car.  I'm waiting to get one from the dealer I purchased from.

 

I WILL be going over everything from the start once I get my throttle body out and checked for run-out.  Ted was nice enough to mail me some bushing that I would never find here.

 

Great points all.  Many thanks!

[Swiss 2002Tii]

OK, so after a summer flu time-out, back to the warm running problem...

 

Firstly, have I found my other mystery "false air" source?  Would it have an effect, being on the outside of the butterfly? :

When I swapped out my starter for a SR440X during the rebuild, the mechanic left off the rear mounting bracket, as it doesn't fit the smaller starter body.  But he left the mounting screw off, so I may have had a constant false air leak.  Starting to feel more hopeful about a properly tuned KF system!

 

I noticed that I have a slight gall on the D-cam shaft:

It appears that this shaft has been repaired (welded and ground) before:

I also should be thinking about a new intermediate shaft - the spring has just about worn through!

 

Aggravated at myself- I cracked this delicate little retaining circlip.  Still functional though.

 

I did a general clean-up of the throttle body (found that the butterfly plate was loose in the shaft):

Ahhhh...much better cleaned up!  Now I can understand the earlier reaction:  What the heck was all of that nasty ol' grease in there for?!!

Bushings on the D-cam shaft have a very slight "play", everything is solid once assembled.  (How do you get those rascals out of there?)

 

I found M5 threaded stock to make my short rods, and I used the original long rod.

The Alfa sockets fit MUCH tighter!

 

Tomorrow it all goes back together... Let the tuning begin!

 

 

 

[Simeon]

The grease may have been an attempt to stop some vac leaked at the bushes. 

[zinz]

13 hours ago, Simeon said:

 

The grease may have been an attempt to stop some vac leaked at the bushes. 

 

 

Good assumption. I do this on the throttle shafts of my old Solex sidedrafts and it works. 

[Swiss 2002Tii]

Well that was a longer and more exhausting reassembly than I expected!  Nothing exceptional just a whole lotta learnin', as this was my first go at throttle body maintenance.

 

Since I had the TB out, and reasonable access, I started by degreasing around the KF and WUR. 

I pulled the central linkage pivot and discovered not two, but one plastic bushing.  I experimented with a couple of materials to make one, but ultimately, a double layer of heat shrink took up the slack.

 

I was going to reinstall my TB support bracket, but my mechanic bent it at the very thin bolt hole point when taking it out, and it got a stress crack and broke when I bent it back into alignment.  I guess I'll bond a steel plate to the two pieces with liquid metal and refabricate it.

 

I had a really hard time getting the KF lever to align for the locking tool.  It is off by about 3mm.  With both short linkages dialed in to 85mm, it just doesn't have the travel to get to the idle locking position.

Ultimately I disconnected the linkages, set the locking pin in place, and then pulled the linkages to connect everything together.  It's not quite right, though, as it jumps the 3mm when I pull the pin.

 

Currently set for:

Locked KF Lever,

Set D-Cam shaft for hole half-covered,

Set the idle screw for edge of hole,

Mixture screw set for one full turn CW from first touch of butterfly lever.

 

Self-inflicted wound:

Grrr... I was taking photos and my camera strap caught the central linkage lever and dragged it off of the hood and chipped my door paint! Ouch!

 

Will do the tuning run in the morning when it's not so hot.

 

[PaulTWinterton]

9 minutes ago, Swiss 2002Tii said:

I had a really hard time getting the KF lever to align for the locking tool.  It is off by about 3mm.  With both short linkages dialed in to 85mm, it just doesn't have the travel to get to the idle locking position.

 

Something doesn't sound right.  All I can think of is that you adjusted the intermediate shaft BEFORE you set up your linkages, causing binding against the idle screw at the TB.  

 

17 minutes ago, Swiss 2002Tii said:

Set the idle screw for edge of hole,

 

That's it, I think.  You should pull the 5mm tool and then do the step above.  Maybe the same result, but just so you know.

 

Remember...you can always move the cam back toward the edge of the hole if the engine runs too rich.

 

Good luck on your first test run. 

[Swiss 2002Tii]

3 hours ago, PaulTWinterton said:

Something doesn't sound right.  All I can think of is that you adjusted the intermediate shaft BEFORE you set up your linkages, causing binding against the idle screw at the TB.

Hey Paul,

 

I agree that something's not right, but I can't put my finger on it.  I had the long linkage disconnected, the D-Cam shaft loose.  It was just the two short shafts connected, and I could not get the KF lever to seat at idle position.  They just wouldn't let it travel far enough.  Remember the short shaft was previously set at 91mm! Looking down at that geared hub on the back of the KF, I just hope nobody had the bright Idea to re-seat that lever!  And they say the verboten screw is verboten!!

BTW, there was no plastic cup for the intermediate shaft in the WUR...

I found my intermediate lever spring that went missing months ago under the cylinder 4 intake runner (twin failure - spring disappeared and dizzy failed at the same time... made for an exciting drive through a 10-mile long tunnel!)  The hook was broken off, but since it's the correct spring, I re-bent the end and replaced the hardware store spring supplied by the mechanic.

4 hours ago, PaulTWinterton said:

That's it, I think.  You should pull the 5mm tool and then do the step above.  Maybe the same result, but just so you know.

  

Remember...you can always move the cam back toward the edge of the hole if the engine runs too rich.

True, I am starting from a completely new starting position.  I could start with the standard configuration and go to the hole half-covered setting if need be.

 

The Alfa sockets have no slop, but they also unseat pretty easily.  I had to tie down the air hose between the WUR and Plenum - it was bumping the intermediate short shaft off of its ball.  Seems to be pretty stable now.  I'll know tomorrow!

 

Tom

[irdave]

There's other stuff along the line of the linkage, right?  All the way from the gas pedal...  You don't have the pedal stop, so maybe it's the wrong pedal?  Maybe the linkage from the pedal is bent and is then too short?

 

There are lots of reasons- probably none of them obvious without another correct car sitting there to compare...

 

Having said that, I'm excited for you.  When they're running even kind of close they are a lot of fun.

[Swiss 2002Tii]

Hi Dave,

Let me describe it more clearly... It's strange, I have nothing connected except the short shaft from KF lever to the intermediate, and from the intermediate to the central pivot lever... everything else is disconnected, nothing to restrict travel.  These two shafts stretch in a straight-ish line, and their length will not allow sufficient travel for the lever to lock at idle.

I'll double-check, but I tried this from a lot of angles, and always came back to this.

 

I adjusted the pedal travel and vertical linkage for the WOT at fifth locking point as well as can be without a pedal stop, no problem on that end of travel.

 

Fingers crossed for my trial run today!

[PaulTWinterton]

1 hour ago, Swiss 2002Tii said:

central pivot lever...

 

Any chance that it's hanging-up?  I can't think of any other reason why the 5mm tool won't line up.

 

Also, make sure the intermediate shaft clamp is loose when you are connecting linkages.

 

I'll check back later.  Good luck.

[irdave]

Do you have the 2 short rods swapped?  The intermediate shaft should be on top, brazed shaft going to the pump going forward should be on the bottom...

 

(I just went downstairs to look and found an old linkage that had them swapped- no way would it work correctly...)

[Swiss 2002Tii]

I'm RICH! I'm RICH!

 

The day almost started with tears... got everything back together, jumped in to take the FunMobile for a spin and... wheeee......wheeee   No starter!

OK, this thing was starting, so it must be something I did in the past days.  Bit the bullet and pulled the air filter assembly again.

I cleaned the big motor ground strap lug (I had moved it to mount the TB bracket), nope.  I checked the black wire to the starter, connected.  Swapped in a spare battery, nope.  Then I thought: "what if there's another spade lug on the starter that I can't see? BINGO!

I had mounted the black wire to the obvious, visible connector, but it actually should connect to one hidden under the starter terminal.  The car gave a funny click, click, click with blinking lights (more later), but started up and ran fine cold.

 

I started out at about 1500-1700 rpm.  AFR was under 9.0

Did loops around my neighborhood to warm it up (I have steep, curvy roads just around the corner).  It ran consistently rich AFR, mostly between 9 and 11, depending on load, and slightly lower under load uphill.  It would go as high as 14.6 when using the engine to brake.

As it warmed up it started running rougher, but the AFR stayed consistently low, mainly under 10.2 or so.  It ran lumpy, but with power, and at least I didn't have to worry about whether I could get it back to the garage.

After warm-up, it was idling at around 700rpm with AFR between 8 and 9, so I first adjusted the idle screw to get it to 900, revved a few times, waited, then adjusted the mixture screw CW in 1/8 increments.  Not much reaction from that, but after a few more runs checked again, reset idle to 900 again and did more increments for a total of a half turn CW.  AFR remains between 9.5-10.2.  

Ultimately, I got to the minimum travel on the idle screw and I'm running 1000rpm, but lumpy, and with some missing.  I can see the black exhaust exiting, and the sensor exhaust mount is completely black. it didn't seem that I was getting much reaction from dialing the mixture screw CW further, So I thought I would come back and re-read all of your advice and come up with a game plan for adjustments.

All things considered, this is a MUCH BETTER situation than before.  The car has power and it's grabbing higher revs much better than before.  It sounds crappy at low revs, but at least I know it will get me home!  More than that, it's feeling pretty sporty, even with the lumpy behavior!

 

Now for the bizarre part...

 

I got back to the garage, let it idle for a minute (AFR still 10.2), and shut off the key... motor kept running.... and running.... couldn't get it to stop!  Finally I pulled the coil wire and got it to stop.

Tried it again, will not stop running...this time I used my kill switch/relay to shut off fuel, but the Yellow Oil pressure and L Battery lamps remained lit, even after I pulled my key!   Crap!  I just replaced my ignition switch a few months ago because my starter was getting power at every key position!

 

 

As follow-up, I again loosened the intermediate shaft to set the D-cam to the edge of the hole.  I first used the locking tool to fix the lever position.  It is a "stretch" to get it to drop in the locking hole, but it goes, just barely.

 

Before I started, I pulled my plugs to inspect them to get a baseline since I'm basically starting from scratch.

First point, the gap on each plug is 0.85mm...  As I recall, the nominal gap is 0.32mm, and I recall a comment from Ed Zinz that he runs NGKs at 0.35mm... "Why waste all of that spark?"   I believe 0.85mm is how they come from the NGK factory.  Should they be adjusted or left as is (ideal setting from manufacturer)?

I have noticed that #2 plug is consistently more sooty than the others.  As I recall, my mechanic said that when they tested my injectors, three tested at 35 bar, and one at 32 bar.  I believe they told me that they put the lower-rated injector in #2.  Since it opens earlier, it must be shooting more gas than the others, right?  I suppose the "miss"  could be flooding on this cylinder?

 

 

I cleaned up the plugs, as I'll want to inspect them again after these tuning runs.  I swapped #2 plug with #4 plug to see if the sooty fouling follows the plug, or stays with the cylinder.  I'm betting on the cylinder.

Any thoughts on next steps for leaning out over the range?

Adjust short linkage? Verboten screw?

 

Tom