‘74 tii fuel delivery issues: last mile? Or rabbit hole?

[0257]

30 minutes ago, ray_ said:

It may be interesting to try to monitor fuel pressure.

 

You have looked at the tank pickup strainer right?

Yeah, replaced it, boiled and otherwise cleaned tank, replaced all fuel lines, cleaned all screens,, replaced the filter…

[ray_]

And checked the fuel pressure under load. Ok.

 

[0257]

Not under load. Hmmm

[0257]

So I took Zouave to the Sarasota Cars & Coffee Saturday where to my surprise there was also a Euro CS Automatic on display.  I took along a friend and on the way of course tried to replicate my stutter/splatter/brapper.  Again, it only occurred in certain rpms in 1st and 2d gears, and not exactly the same way each time, and it took my companion about 10 seconds to suggest that maybe it was actually not a fuel issue at all, but a rattle in the tunnel. 

 

You know?  That 5-speed was a pretty tight fit on the left side of a tunnel that is narrower than most (I had to cut Blunt's cross-mount down by almost half an inch to get it up into the tunnel at all.  I wonder if the torque effect of gunning the engine in 1st and 2d is enough to just nudge two elements into contact briefly, with the vibration making it feel as if the engine is under stress.  It would make sense that the torque would be less in higher gears... and as I recollect perhaps this has only been happening at all since I did the 5-speed swap, during a period in which I also did a lot of other work and the car sat on stands for months.

 

Sometimes not having a reputation as a competent professional is a good thing.  The fall is shorter.  I wil be stuffing silicon rubber sheets up into the tunnel to see if I can isolate this better.  But on reflection, I think maybe we have found the problem at last.

 

In case you don't think there'd be an additional penalty (beyond redoing the entire fuel system) for this idjicy, I assure there was: in reassembling the instrument binnacle with everything now plugged in (including a new speedo cable), I at first had no problems at all. Then my blinkers failed and every time I flicked the stalkI got a buzzing sound from the relay.  I fiddled around with it all a bit and then blinkers worked and less buzz but relay going too fast.  And no green dash light. For that matter no blue brights light -- everything else on the panel splendid.  Flashers work, though the first time I tried them I had front flashers and rear static taillights.  I played with fire taking those instruments out again, and got burned.  Reading lots of threads on that.

 

Very appreciative of all the thoughts offered on this fuel delivery topic.

[ray_]

Honda makes good cars. Dependable. Run well. No rattles. Lights work...

 

 

I had assumed you were seeing a corresponding blip in AFRs with the latest conundrum. If not, then hey... it's running right.

 

Cheers,

Edited December 13, 2021 by ray_

[0257]

10 hours ago, ray_ said:

Honda makes good cars. Dependable. Run well. No rattles. Lights work...

 

 

I had assumed you were seeing a corresponding blip in AFRs with the latest conundrum. If not, then hey... it's running right.

 

Cheers,

We don’t need to talk about how long it took me to figure that out. ?

[0257]

After replacing the flasher relay and all the bulbs,and a brief pause to regain my emotional stability, I have been driving Zouave, which runs pretty well now.  Still, I have continued fiddling with Zouave’s fuel injection system to address a few unexplained anomalies (like real rich idle and some real lean readings at partial throttle at some speeds/gearing).  

 

In that connection, I have now found at least 4 threads in which someone asks the question: what is the length of tii fuel injection linkage #1 AND GETS NO ANSWER (THIS INCLUDES YOU, CD, THOUGH YOU HAVE BEEN KIND ENOUGH TO POST DIAGRAMS THAT DESCRIBE JUST ABOUT EVERYTHING ELSE).  This appears to be a pretty big hole in the shared knowledge on this site, and I see nothing in my blue book, any of the Tii Register articles or on RealOEM that settles it, either.  It’s a black hole, ignored.  Can anyone answer this question?

 

I ask because I’m having a problem getting my linkage set up correctly at idle.  To wit, according to the manual, at idle the linkage is supposed to be set so that hole #1 on the KF pump lever is lined up with the hole in the pump body.  I’m not getting alignment.  

 

My new BMW KF-to-intermediate shaft linkage rod (part #13.51.1.260.343) is set 85mm.  My #1 linkage rod, as it is referred to in various diagrams I have seen (the one that connects the big lever on the block and the intermediate throttle shaft, part 35-41-1-113-788) came from BMW adjusted to 85mm.  However, when both are fitted on the car, hole #1 on the KF pump lever is not quite lined up with the hole in the pump body.  The hole on the pump lever hangs a bit lower than the hole on the pump body (ie, you have to pull the accerator linkage just a touch to get them to line up) .  Trying to determine whether the right way to fix this is to shorten linkage #1 a bit, or whether that’s just a bad idea.

 

I note too that my intermediate shaft (when under spring pressure) stops returning only when the horizontal platform on the intermediate shaft whaps up against the #2 intake runner.  See photo.

 

That does not strike me as a design feature, y’all.  

 

Can anyone say how this shaft’s rotation actually should be stopped so that the two 85mm linkage rods don’t shove the KF pump lever out of alignment with the hole in the pump?  Aside from shortening linkage rod #1, one way would be to shorten the 289mm horizontal linkage rod, or the vertical accelerator linkage rod so that there’s a positive stop in the linkage system.  But I understand that shortening the 289mm linkage rod leaves you without a good WOT.  Has anyone seen and solved this issue?

 

Those of you who have followed my piteous progress on this issue will know that everything in my fuel delivery system except the KF pump itself is new or renewed, valves repeatedly adjusted, 123 nicely dialed in, etc. So no need to cut and paste all that advice, CD!  But any and all other advice appreciated.

[bergie33]

Please, someone correct me if I am wrong, but isn't the bolt next to the enrichment lever there as a stop for the linkage?  See the circled area in the pic below.  I think backing out this bolt a touch would get your linkage to return to the correct resting place.  When the enrichment lever is pulled back by the return spring, the arm where the ball stud attaches, comes to rest on that bolt.

 

[0257]

2 hours ago, bergie33 said:

Please, someone correct me if I am wrong, but isn't the bolt next to the enrichment lever there as a stop for the linkage?  See the circled area in the pic below.  I think backing out this bolt a touch would get your linkage to return to the correct resting place.  When the enrichment lever is pulled back by the return spring, the arm where the ball stud attaches, comes to rest on that bolt.

 

I am as likely as anyone on this forum to get things completely backwards, but I think that stop is only there to keep you from over-throttling at WOT.  At full extension of the accelerator pedal, you’re supposed to be able to put your 5mm pin into the pump body at lever hole #5 (bottommost hole in your photo), with the stop keeping you from cranking the pump any further.  My issue is on the other end of the lever, hole #1.   When my foot is off the pedal, hole #1 is off center to the hole, a bit too low for a perfect fit.

 

I should add that this only started being a problem when I finally replaced linkage rod #1.  It wasn’t even a problem pinning hole #1 at first then, but when I loosened the intermediate shaft to move the d-cam further over the hole, this misalignment appeared (makes sense, as the ends of the new rod are much tighter than the old rod) and doesn’t seem to want to go away.

[bergie33]

5 minutes ago, 0257 said:

I am as likely as anyone on this forum to get things completely backwards, but I think that stop is only there to keep you from over-throttling at WOT.  At full extension of the accelerator pedal, you’re supposed to be able to put your 5mm pin into the pump body at lever hole #5 (bottommost hole in your photo), with the stop keeping you from cranking the pump any further.  My issue is on the other end of the lever, hole #1.   When my foot is off the pedal, hole #1 is off center to the hole, a bit too low for a perfect fit.

 

I should add that this only started being a problem when I finally replaced linkage rod #1.  It wasn’t even a problem pinning hole #1 at first then, but when I loosened the intermediate shaft to move the d-cam further over the hole, this misalignment appeared (makes sense, as the ends of the new rod are much tighter than the old rod) and doesn’t seem to want to go away.

 

Yep, you are correct....I had it reversed.  After reviewing the Fuel Injection manual, it says after adjusting the eccentric cam (in the throttle body tuna can), you should be able to re-insert the hook easily with the cam against the pin.  Now, the 85mm length of the linkage is gospel and shouldn't be changed.  Adjusting that length not only changes how things initially line up, but will also adversely adjust the fuel ratio throughout the throttle curve.  You need to make your adjustment where the vertical linkage attaches to the rod coming down from the eccentric cam in the throttle body.  See Page 15 in the injection manual.

 

If you don't have the Fuel Injection manual yet, download it here:

 

 

 

[dlacey]

5 hours ago, 0257 said:

To wit, according to the manual, at idle the linkage is supposed to be set so that hole #1 on the KF pump lever is lined up with the hole in the pump body.  I’m not getting alignment.  

When are you not getting that alignment? during the mechanical setup / initial setting of the linkage? or during real-life idle condition?...in real-life when the tuna-can idle adjustment screw is set, the linkage will be moved somewhat and the Kugel pump hole wont line up.

 

 

As I read it, it says that the 5mm hook only goes in to the idle hole during the setup phase..once the idle adjustment screw is set for real-life idle, the 5mm hook will not align with the pump body hole

[ray_]

10 minutes ago, dlacey said:

When are you not getting that alignment? during the mechanical setup / initial setting of the linkage? or during real-life idle condition?...in real-life when the tuna-can idle adjustment screw is set, the linkage will be moved somewhat and the Kugel pump hole wont line up.

 

 

As I read it, it says that the 5mm hook only goes in to the idle hole during the setup phase..once the idle adjustment screw is set for real-life idle, the 5mm hook will not align with the pump body hole

This is what I remember as well.

 

And that hole in the tuna can under the D cam -- the hole itself was/is adjustable and I believe was adjusted per car on the assembly line, if I am rightly remembering what I read here.

 

Cheers,

 

[0257]

13 minutes ago, dlacey said:

When are you not getting that alignment? during the mechanical setup / initial setting of the linkage? or during real-life idle condition?...in real-life when the tuna-can idle adjustment screw is set, the linkage will be moved somewhat and the Kugel pump hole wont line up.

 

 

As I read it, it says that the 5mm hook only goes in to the idle hole during the setup phase..once the idle adjustment screw is set for real-life idle, the 5mm hook will not align with the pump body hole

Hmmmm.  I’ll go look at this in the morning (btw, good morning, dlacey).  Maybe backing off the idle screw and a/f mix screw in the tuna can before initial adjustment will move things enough that we get alignment.  Doesn’t seem that would make that much of a difference, but….  And do you find that your intermediate shaft platform stops against your intake runner?  If not, how far away is it from stopping there (if you have a sense of it)?

[dlacey]

11 hours ago, 0257 said:

do you find that your intermediate shaft platform stops against your intake runner?  

 

Healthy gap over here

[0257]

Thanks for the inputs, y'all.  I started from front and worked my way back, working with a short manual I got from Keith Kreeger (I think from the tii Register site).  Turns out (I am pretty sure) I had the vertical rod from the pedal box too tight, pushing on the 289mm rod (and thus the whole linkage assembly) and throwing it too far forward by a mm or so when under the load of all those new return springs.  By resetting the linkage with that vertical rod disconnected I got the holes to line up, then reconnected the vertical rod as indicated in the manual, where it just barely is high enough to pass through the hole in the firewall bracket.  As a result I can pin lever  hole #1 in the pump body at idle, and lever hole #5 in the pump body at full accelerator extension (with the lever pegged against the stop bolt as indicated in the manual).  The intermediate shaft is held off the manifold now, and all is well with the world -- except I still haven't dialed out my mixture issues yet!

 

That's tomorrow.  And I think I may have another question about the warmup regulator shortly.  But that's for then too.