1979, 504 Ti - Running rich

[Alex Foss]

Hi all.

Had a couple of test drives today after some adjustments. I turned the big screw on the pump head half a turn towards lean, and then adjusted the CO and air bypass screw til i had a steady idle on 900rpm, and got the following AFR result:

Idle: 14,5 on 900rpm
Cruising on low throttle: 9-10
Slow acceleration: From 9 to 12
Full throttle: It jumps up to 17-18 and it stops pulling, regardless of rpm, gear and speed. This is the same flat spot as i have mentioned earlier, but back then i thought it was flooding, but its the opposite, it doesnt get enough fuel.

If i adjust the big screw in the pump head half a turn towards rich, the flat spot is gone, but then it runs way too rich in the whole register.
I would have wanted it a little leaner than it is now, maybe around 13 like BIGRR mentioned, but its not really driveable since it doesnt get enough fuel on full throttle.

 

[Mike Tippett]

There's something weird going on in the pump or pneumatic diaphragm.....but exactly what, I don't know.

 

[BIGRR]

Alex,

looks like you are within a "Bull's Roar".

Just flashed through this thread, can't see a confirmation of checking flow rates and delivery pressures of your ELECTRIC fuel pump at the injection pump inlet. Are all the lines clean and clear?

Just to please me, try pinching the inlet air hose off partially on the Altimeter "thingo". My car stops instantly if I camp this line fully off. You could maybe rule in/out that this is not your problem. If you were to test drive the car with a clamp on this hose at a number of different partial clamp settings (similar to adjusting the internal bellows air inlet, without upsetting things) and see how this affects AFRs.

Not heard of M95 distributor on a Ti. (M53 & M58?)

A mate off mine years ago had a afr gauge on mine and I do remember seeing a couple of 20's pop up under test. Can't remember under what conditions.

My money is on your electric fuel pump! (?) ((I am running out of money though!!))

 

[dacia4x4]

Is the big screw on the pump head you describe the anchor mount for diaphragm return spring?if so can you can go at small increments if I remember it is locked in by an Allen key bolt which clamps the thread,so why not try an eighth or quarter turn lean from your start point,reset mixture,idle and road test at that…just a thought jim

 

[Alex Foss]

Alex,

looks like you are within a "Bull's Roar".

Just flashed through this thread, can't see a confirmation of checking flow rates and delivery pressures of your ELECTRIC fuel pump at the injection pump inlet. Are all the lines clean and clear?

Just to please me, try pinching the inlet air hose off partially on the Altimeter "thingo". My car stops instantly if I camp this line fully off. You could maybe rule in/out that this is not your problem. If you were to test drive the car with a clamp on this hose at a number of different partial clamp settings (similar to adjusting the internal bellows air inlet, without upsetting things) and see how this affects AFRs.

Not heard of M95 distributor on a Ti. (M53 & M58?)

A mate off mine years ago had a afr gauge on mine and I do remember seeing a couple of 20's pop up under test. Can't remember under what conditions.

My money is on your electric fuel pump! (?) ((I am running out of money though!!))

BIGGR, this video is just for you

I have checked the pressure from the fuel pump, flushed the tank, and all fuel hoses are new.

M95 is also used, at least in europe.

If it was just the number, that it was running lean in some conditions, i wouldnt mind but the engine stops pulling so its clearly something wrong.

I disassembled the pump-block on the Kugel today. There was some debris here and there, and the o-rings on the valves are done, so its leaking engine oil in to the pump-block. See picture, the bottle on the left is what came out, and its only some months old.

I really hope cleaning and overhauling it will do some good.

One other thing, i read from a French autoshop that the altitude corrector could cause flat spots on the throttle, as well as either running rich or lean. Does anyone know how to controll, and if necessary rectify it ?

 

[BIGRR]

Nice pics.

The oil in my pump always runs black, I have only ever changed it about 3 times in 360K km, does not

Your 1st film test: My car stops instantly, if fully clamped off!

Appears that the Altimeter "thingo" setting may very well be your problem. It may have been fitted to the engine when you received the car but it may not be the original paired one or has been fiddled with.
Think about what it does, it controls where the main diaphragm usually runs and this controls the normal running mixture.

Would be interesting to measure afr as you partially clamp the hose of at differing positions!

Quote: One other thing, i read from a French autoshop that the altitude corrector could cause flat spots on the throttle, as well as either running rich or lean. Does anyone know how to controll, and if necessary rectify it ?

The Altimeter "thingo" can be adjusted. I have never done it, though imagine it would have to be moved only by thousands of an inch at a time. (Trial and error). You could try this with one of your spare "thingos"? Nothing to lose.


Good luck

 

[Alex Foss]

Nice pics.

The oil in my pump always runs black, I have only ever changed it about 3 times in 360K km, does not

Your 1st film test: My car stops instantly, if fully clamped off!

Appears that the Altimeter "thingo" setting may very well be your problem. It may have been fitted to the engine when you received the car but it may not be the original paired one or has been fiddled with.
Think about what it does, it controls where the main diaphragm usually runs and this controls the normal running mixture.

Would be interesting to measure afr as you partially clamp the hose of at differing positions!

Quote: One other thing, i read from a French autoshop that the altitude corrector could cause flat spots on the throttle, as well as either running rich or lean. Does anyone know how to controll, and if necessary rectify it ?

The Altimeter "thingo" can be adjusted. I have never done it, though imagine it would have to be moved only by thousands of an inch at a time. (Trial and error). You could try this with one of your spare "thingos"? Nothing to lose.


Good luck

Thanks again BIGGR.

"Your 1st film test: My car stops instantly, if fully clamped off!" - Even when the engine is cold? It will still get air thru the thermostatic element?

Regarding the altimeter, i will check if there is any way of identifying it, but have no reason to believe that its not the original one. Also, keep in mind that the car ran great for 10 years in my possession, so if its anything regarding the altimeter i guess something must have broke?

When i get the pump-block back in place, if its not any better, i will do some tests as you suggest with the hose, and maybe trying a different altimeter.

 

[BIGRR]

Thanks again BIGGR.

"Your 1st film test: My car stops instantly, if fully clamped off!" - Even when the engine is cold? It will still get air thru the thermostatic element?

Regarding the altimeter, i will check if there is any way of identifying it, but have no reason to believe that its not the original one. Also, keep in mind that the car ran great for 10 years in my possession, so if its anything regarding the altimeter i guess something must have broke?

When i get the pump-block back in place, if its not any better, i will do some tests as you suggest with the hose, and maybe trying a different altimeter.

The air coming through the "thingo" does not mix with the engine inlet gases it just counterbalances the main diaphragm vacuum that pulls up or down the mixture ramp. (I say).

I did not know that the engine had run for 10 years under your ownership! (Helps a lot!)

Just found this article on a BMW site (Though they were talking 504)
""Dunno if you solved the problem but I may have useful info for you....I had a Kugelfisher injected 504 coupe that ran rich..over a year it got worse until it was nearly undriveable and impossible to start when hot.
I removed and checked everything related to the delivery of fuel .. eventually removed the pump and stripped and cleaned it...nothing made a bit of difference. One day a pal who's a proper old school motorcycle mechanic visited me. We stood staring at this engine chuntering away, idling like a pig and stinking of fuel at the back end. He simply stood there staring at it for about a minute, then reached forward and poked the throttle butterfly spindle, and pushed it gently ...the engine changed dramatically ...it sounded wonderful

Turns out that the spindle bushing was worn, allowing air to bleed into the intake tract behind the butterfly ...contrary to normal experience, instead of causing weak running as you'd expect with air leaks into the intake...the leak causes REDUCED VACUUM which the pump's reference ( via the pipe to the plenum chamber ) reads as an opening throttle and thus up fuels the engine 'thinking' the engine is turning harder than it is.

Simply squirting spray grease onto the ends of the spindle transformed the car by sealing the spindle ends and it drove beautifully pending a rebush.""

DOUBT YOUR SHAFT WOULD BE THAT WORN. Mine is worn, though only makes minute change if pushed around. Though worth a check and makes sense. In the Pug manuals for some reason it describes how to re-bush this spindle/bore?

 

[neil s]

Would a vacuum gauge show any of this possible dodgy spindle issue?

 

[Alex Foss]

New video for you, BIGRR

Got it back together, no imediate difference. Tried the second altimeter, no difference.

I made several (4 or 5) new attempts with adjusting the big screw/spring. When i set it at least one quarter turn towards rich from the initial setting (where it ran good for years) i no longer have the flat spot on full throttle. But i still have the flat spot on initial throttle, somewhere around 12-1500 rpm. And no matter what i do with the big screw/spring and the CO i still have this wierd phenomenon that it runs rich on low throttle and leaner on more throttle. From what i understand, it should be the direct opposite, lean when cruising and richer on open throttle. Correct me if im wrong.

 

[Alex Foss]

The air coming through the "thingo" does not mix with the engine inlet gases it just counterbalances the main diaphragm vacuum that pulls up or down the mixture ramp. (I say).

I did not know that the engine had run for 10 years under your ownership! (Helps a lot!)

Just found this article on a BMW site (Though they were talking 504)
""Dunno if you solved the problem but I may have useful info for you....I had a Kugelfisher injected 504 coupe that ran rich..over a year it got worse until it was nearly undriveable and impossible to start when hot.
I removed and checked everything related to the delivery of fuel .. eventually removed the pump and stripped and cleaned it...nothing made a bit of difference. One day a pal who's a proper old school motorcycle mechanic visited me. We stood staring at this engine chuntering away, idling like a pig and stinking of fuel at the back end. He simply stood there staring at it for about a minute, then reached forward and poked the throttle butterfly spindle, and pushed it gently ...the engine changed dramatically ...it sounded wonderful

Turns out that the spindle bushing was worn, allowing air to bleed into the intake tract behind the butterfly ...contrary to normal experience, instead of causing weak running as you'd expect with air leaks into the intake...the leak causes REDUCED VACUUM which the pump's reference ( via the pipe to the plenum chamber ) reads as an opening throttle and thus up fuels the engine 'thinking' the engine is turning harder than it is.

Simply squirting spray grease onto the ends of the spindle transformed the car by sealing the spindle ends and it drove beautifully pending a rebush.""

DOUBT YOUR SHAFT WOULD BE THAT WORN. Mine is worn, though only makes minute change if pushed around. Though worth a check and makes sense. In the Pug manuals for some reason it describes how to re-bush this spindle/bore?

BTW, I read the same article a year ago, and so the spindle has been tested regularly with start gas, its not leaking air.

 

[BIGRR]

Spent more time reading testing my car and thinking about your problem. Would love to see the car go properly for you.

Just read your above 2 posts and had come to the same conclusion, re main spring position and Altimeter.

This afternoon I started my Ti and clamped immediately (on choke) clamped off the air to altimeter, it behaved the same as yours in film at #125.

And mine has a stutter if I open the throttle a large amount quickly from idle. Only for a fraction of a second though just off idle and then it revs out.

Just a couple more items/checks I thought of worth a try or for confirmation.

Try when tuning to forget about the CO levels (As far as I remember Peugeot Australia could not get the Ti's to run better than around 7% that is why they stopped importing the Ti motor)?

Is the small hose between the manifold front bottom (at the butterfly) connected to the vacuum advance?

Are the electric fuel pump lines connected in the correct order?

Are you getting enough voltage to the electric fuel pump?

Did you do a flow test on electric pump delivery?

I viewed a Youtube clip on the problems these electric pumps come up with. On Mec's and BMWs they fit an accumulator in the pump lines. Mainly vapour locks when restating hot.

Have you timed (sprocket angle location) on the injection pump for a XN2/KF5 and not for a KF6?

I see on one of the YouTube clips that there are different mixture ramps available.

Something I can't fathom is the short hose that runs from the oil filler top to the inlet manifold, how come this does not interfere with idle speed? It has no seal on the aluminium filler neck.

Food for thought.

 

[BIGRR]

KF6 pump is early Ti. Assume you have used this site http://www.504.org/ full copy of 504 manuals available. (See page 1319 of engine manual). Previous owner or someone may have retimed pump and used early manual settings?

Re: Yesterday. Air entering through thermostatic element shaft. If the engine was running under 80C. It may have been partially open.

Re: Video of my "stutter" Ha Ha! I am No computer expert at all. I am a 1948 model (sorry).
It is a quick stutter say 1/3 of a second and is a bit like the engine timing has retarded too far. Can't be felt driving.

All the electric pump hose connections and specs. are shown in the 504.org engine manuals.

 

[Mike Tippett]

The 404 KF2 definitely does have a supplementary air valve built into the thermostatic element, which hisses when the car's cold. But it should be closed above about 50C.

 

[goodgriefmike]

BTW, I read the same article a year ago, and so the spindle has been tested regularly with start gas, its not leaking air.

Hi Alex, (been reading this thread with active interest as I am trying to get my KF system running better. On the head unit, I measured the internal distance on two different head units I have. I got 16.78mm and 16.59mm (Picture attached)

 

[goodgriefmike]

I also found that the internal pipes/holes at the front of the intake manifold were blocked / and or clogged (Where we look for the light to set the butterfly valve) Also, the vacuum advance hole was completly blocked, Here is a pic of what i refer to.

 

[goodgriefmike]

And since I'm on with mine, I send a pic of an altimeter and have a general question for all... (I am at sea level)
I am interested to know the 'base/starting point- position for the altimeter. As you can see, there is round hole, then a solid gap, then a long slot to allow more air to be pulled through.

I wonder how many feet (altitude) would be required for the bellows to expand such that the slide cover would be pushed far enough to start opening the 'slot'... (I think it would be a few thousand feet?)

This brings us back to the initial setting, IF the slide plate is set such that the round hole is 'open' at Zero feet, it basically means that it never gets covered by the slide mechanism (weird barometric events notwithstanding)

It also means (because of the large solid gap between the round hole and the high altitude slot) that for most driving scenarios, the barometric movement would fall between the open hole, and the fixed area before the slot. (If that's the case, it would mean no impact from the altimeter on the mixture of the KF pump.

So, I am back to wondering whether the initial / sea level setting of the Altimeter (in conjunction with the head unit) has the altimeter slide in such a position that it DOES cover the round hole very very slightly??

Any insight and thoughts on this would be much appreciated.

 

[BIGRR]

I live at RL.55m.
By eye, yours looks to be set very very close to min. (My car runs well.)
I can't add photo, sorry.

 

[BIGRR]

Note: above should read set very close to mine not "min".