1979, 504 Ti - Running rich

[BIGRR]

Suggestions:
Is the breather hose between top of oil inlet and the inlet manifold clear to breath?
Do you have the steel wire filter in the oil filler tube, or?
Does smoke still come out of the dipstick if the oil filler inlet tube lid is opened?
Try adjusting the gap on the choke rod gap in by (say) 2mm and see if this helps with a faster idle. Air is introduced to the inlet manifold through the top of this shaft when the engine is on choke. (Always surprised me as this air is not filtered).
I asked once before if you were sure that the inside of the choke water chamber was clean of old radiator dirt. I think if you remove both water hoses you can poke a fine wire in and then hose it out to check.
Are all your adjustments done at (the magic) 80 degrees C. ?
Try giving the hose between the air cleaner and the altitude gizmo a partial squeeze off this should upset the tune/idle thus proving the hose is clear.
Is the fuel outlet (Return to tank) connector on the outlet side of the mechanical pump the correct one, it is a restrictor of flow?

Maybe grasping at straws but it does sound like it is something simple.

 

[Alex Foss]

Suggestions:
Is the breather hose between top of oil inlet and the inlet manifold clear to breath? Yes, new hose
Do you have the steel wire filter in the oil filler tube, or? Yes, also new.
Does smoke still come out of the dipstick if the oil filler inlet tube lid is opened? Havent tried this yet, but i will!
Try adjusting the gap on the choke rod gap in by (say) 2mm and see if this helps with a faster idle. Air is introduced to the inlet manifold through the top of this shaft when the engine is on choke. (Always surprised me as this air is not filtered). Yes this helps, but just until it reaches op. temperature and the shaft closes off the "extra" air.
I asked once before if you were sure that the inside of the choke water chamber was clean of old radiator dirt. I think if you remove both water hoses you can poke a fine wire in and then hose it out to check. Yes i am sure, i`ve had the thermo-element off and in pieces and cleaned everything.
Are all your adjustments done at (the magic) 80 degrees C. ? Yes and no. I dont think it reached 80 the last time, because the idle rpm was so low it stalled.
Try giving the hose between the air cleaner and the altitude gizmo a partial squeeze off this should upset the tune/idle thus proving the hose is clear. Thanks, i will try.
Is the fuel outlet (Return to tank) connector on the outlet side of the mechanical pump the correct one, it is a restrictor of flow? Original outlet. Is there a strainer there also? If so, i should check that again.

Maybe grasping at straws but it does sound like it is something simple.

BIGRR, please see my response above in your text. Im thinking it might be too lean of a mixture now? Does anybody know what the base setting of the big mixture screw in the pump-head is? As mentioned, mine measures 19mm above, see picture.

 

[BIGRR]

If you go back to #13 it reads (basically) the same as your latest findings at post #100, so that may rule a few things in OR out.
Would appear to be a fine tuning problem.
Too rich?
Is it still running rich at the exhaust pipe? Can you measure the fuel/air ratio at the pipe? See #5
Can you try leaning it off at the lever/grub screw at the bottom of the pump? Maybe a couple of complete turns (or do you still have no adjustment to lean?) Less fuel, should = more revs at idle? I think if you get this + or - one complete turn from its correct place on final tune that it will not hurt. I have set mine at where I recon is correct, then give it 1/2 a turn rich. (Trial and error) Remember this should be reset last after every trial adjustment.

Don't forget I still say the butterfly fine set up is the most important setting. (If you get it to idle).
There may also be something in #33. I bought my Ti new and at 600 miles at its first service they made adjustments to the tune and after this, it performed better. (Timing and ???)

You could also remove the lid of the altitude gizmo and have a check if it all looks OK in there. This will not affect the settings. What do you mean in your posts "the matching-number" barometer?

Is the orifice plate in behind the square holed plug at the front of the intake manifold still clear?

Lastly you may have to trial and error adjust the big spring setting say 1/2 turn at a time. I know your 2 pumps are set the same, however I fail to see how anyone could make a spring that accurately that all pumps would be set at 19mm. 19mm maybe a good rough starting point though. I am not volunteering to disconnect and reconnect all the fittings for this operation though!

 

[Alex Foss]

If you go back to #13 it reads (basically) the same as your latest findings at post #100, so that may rule a few things in OR out.
Would appear to be a fine tuning problem. You are right, acting just the way it did back then.
Too rich?
Is it still running rich at the exhaust pipe? Can you measure the fuel/air ratio at the pipe? See #5 I did perform a CO reading, it was 3% but that was before i started messing around trying to get rid of this "flat spot".
Can you try leaning it off at the lever/grub screw at the bottom of the pump? Maybe a couple of complete turns (or do you still have no adjustment to lean?) Less fuel, should = more revs at idle? I think if you get this + or - one complete turn from its correct place on final tune that it will not hurt. I have set mine at where I recon is correct, then give it 1/2 a turn rich. (Trial and error) Remember this should be reset last after every trial adjustment. Right now, i have a lot of adjustment towards lean to go on, if you see #100 i tried a "base setting" with the enrichner screw ca one turn outside the nut (quite rich).

Don't forget I still say the butterfly fine set up is the most important setting. (If you get it to idle).
There may also be something in #33. I bought my Ti new and at 600 miles at its first service they made adjustments to the tune and after this, it performed better. (Timing and ???) I absolutely agree with the butterfly, it just bothers me that when i adjust it accordingly to the manual, the air bypass screw has no effect on the idling.

You could also remove the lid of the altitude gizmo and have a check if it all looks OK in there. This will not affect the settings. What do you mean in your posts "the matching-number" barometer? I had a look inside, doesnt look like anythings broken or anything. (Photo). By "matching-number" or numbers-matching i meant its the altitude corrector that came with the pump, as i have tried others as well.

Is the orifice plate in behind the square holed plug at the front of the intake manifold still clear? Yes

Lastly you may have to trial and error adjust the big spring setting say 1/2 turn at a time. I know your 2 pumps are set the same, however I fail to see how anyone could make a spring that accurately that all pumps would be set at 19mm. 19mm maybe a good rough starting point though. I am not volunteering to disconnect and reconnect all the fittings for this operation though! My third pump measured 22mm (richer).

Thanks again BIGRR, please see my responses above.

 

[BIGRR]

Thanks again BIGRR, please see my responses above.

I would be giving the big spring a (trial) tweak, 1/2 a turn lean? Then twiddle the butterfly (I think the "light" setting is a close starting point). Nothing to lose!

 

[Alex Foss]

Todays update.

I cleaned the spark plugs, checked the gaps, adjusted the butterfly with the light gap and started it up. I checked the water-coolant temperature, and when it reached 80*C i performed the "enrichment test" according to the manual. See the last video.

After several corrections on the air bypass and the enrichner screw, i managed to obtain a increase in RPM from ca 900 to ca 1050. All good so far.

But, i still have the flat-spot when i barely open the throttle, maybe around 1000-1200 rpm somewhere, and also, when i took it for a test drive, when i hit full throttle, its almost like it stalls. On lets say 3/4 open throttle it pulls fine, but on full throttle it seems like its flooding of fuel, or maybe lack of fuel? I dont know.

Oh, and one last thing. As the video shows, when around 2000rpm the engine is shaking a lot, is this normal on these engines when its not under load?

 

[ThanosK]

A Ti engine in good tune pulls very smoothly with no power gaps from idle to 6000 rpm. To me it looks that the engine is misfiring in the video, hence the shake. Did it do that the first time you started it after the rebuild? Do you have an exhaust gas analyzer so you can monitor your mixture during driving? If not, a dyno tune may be a good option. If you are concerned because this is a new engine. run it in second instead of fourth gear and only to 4500 rpm.

 

[Alex Foss]

A Ti engine in good tune pulls very smoothly with no power gaps from idle to 6000 rpm. To me it looks that the engine is misfiring in the video, hence the shake. Did it do that the first time you started it after the rebuild? Do you have an exhaust gas analyzer so you can monitor your mixture during driving? If not, a dyno tune may be a good option. If you are concerned because this is a new engine. run it in second instead of fourth gear and only to 4500 rpm.

It pulls fine, except when you gently open the throttle and with full open throttle. Inbetween no problems. I just checked the timing again, and made a small correction, it was a bit off. Made no difference while driving.

Unfortunately i dont have an exhaust gas analyzer.

 

[ThanosK]

It pulls fine, except when you gently open the throttle and with full open throttle. Inbetween no problems. I just checked the timing again, and made a small correction, it was a bit off. Made no difference while driving.

Unfortunately i dont have an exhaust gas analyzer.

It pulls fine, except when you gently open the throttle and with full open throttle.
Well, I wouldn't call that pulling fine. If it doesn't work well at WOT, there is clearly a problem, as many maladies are reduced at WOT. And you can see/hear the engine running on three cylinders (maybe even two) at 2000 rpm. WHY?

I just checked the timing again, and made a small correction, it was a bit off. Made no difference while driving.
The timing doesn't account for the engine shaking like that, it is really critical to find the cause before going any further.

Unfortunately i dont have an exhaust gas analyzer
Then the dyno is the only way to get an answer to your fueling problems. I think you have gone as far as you can go in your investigation with the workshop manual methods, and, in my opinion, you have addressed all the KF parameters.

Have you taken cylinder pressures?

 

[ThanosK]

I just had another thought: The KF pump operates on vacuum, that's why you can't use a much bigger cam with the Ti engine. Is the cam timed correctly? Are you sure you are using a XN2 cam? If the cam is timed incorrectly or has more of an overlap fueling will be inconsistent.

 

[Alex Foss]

Please elaborate? Like someone mentioned here earlier, the Haynes manual got it wrong, so at first it did not fire, until i turned the distributor 180 degrees.

Alex I've found with mine it needed to have perfect setting of the ignition system first with number 1 piston at TDC " back of engine"
in ignition stroke with the smaller offset of the distributor drive facing the Ti pump with the groove pointing to very front right head bolt.
I used a 123 distributor in M53 curve with number 1 distributor lead at 11 o'clock .

pugmachine, the smaller offset should face the engine block, not the pump?

 

[207cc Sport]

How Rich?

 

[Alex Foss]

How Rich?

View attachment 207034

12 mpg rich...

 

[Alex Foss]

Last time i went for a run, 12 mpg...

Since then i have fitted an original M95 distributor and some borrowed injectors with low mileage and good spray pattern. I havent checked the consumption again yet, but i no longer have the flat spot on full throttle, but the flat spot or drop if you like on slightly throttle around 1200-1500 rpm is still like before, see video.

 

[PeterT]

I've been following this for a while. I can't help think how much time you may have saved, if you had bought a wideband sensor kit. You will instantly see the results of your changes. There is no need to install it permanently. Construct a sample pipe to stick up the tailpipe and go for a drive.

 

[con]

I've been following this for a while. I can't help think how much time you may have saved, if you had bought a wideband sensor kit. You will instantly see the results of your changes. There is no need to install it permanently. Construct a sample pipe to stick up the tailpipe and go for a drive.

yes, see number 5.

 

[Alex Foss]

yes, see number 5.

I have ordered one, waiting for it to arrive.

 

[Alex Foss]

yes, see number 5.

I have now installed the wideband sensor kit, and had a short drive. When i hit the flat spot on the throttle the AFR drops from around 10 down to 5, indicating its getting flooded with fuel.

What AFR would you recommend to aim for, and when do i measure it, at full throttle? Cruising speed? What about when idling?

Thanks

 

[BIGRR]

My 205 was dyno tuned in 2008 (Cost me $900 aud).

The mixture he aimed at for all rpm was 13.1 to 1. The dyno printout backs this ups. The car has run very very well at this afr and has for the past 14 years and still dose. Very (minute) slight black smoke on full throttle.

 

[Alex Foss]

My 205 was dyno tuned in 2008 (Cost me $900 aud).

The mixture he aimed at for all rpm was 13.1 to 1. The dyno printout backs this ups. The car has run very very well at this afr and has for the past 14 years and still dose. Very (minute) slight black smoke on full throttle.

Thanks for the input, BIGRR!