1979, 504 Ti - Running rich

Is the distributor in good nick? If the centrifugal advance is stuck, you might have the advance right for idle but way retarded at higher revs which would give poor economy and performance. Vacuum advance is also important for economy. Here are a couple of checks:

Take the dizzy cap off and disconnect vacuum advance hose. Sucking on it, does the advance plate move, does the vacuum hold, and does the plate return when you release the vacuum?

Put the dizzy cap back on, but block off the vacuum advance. Run the engine with the timing light. Watch the marks as you raise the revs from idle to about 2500. You should see the mark move smoothly towards the left (advance) as the revs increase.

Have fun,

Rob.
 
I am assuming your injectors have been tested for opening pressure. Disconnect the electrovalve and see if this hesitation goes away. Is the car harder to start when warm?
 
On another note, I know this is not everyone's experience, but we had very rough running with 123 distributors (the blue-tooth version). Tried two of them, then ended up tossing them and going with programmable MSD. Although this would not explain the black smoke.
 
Your MPG figures seem low. TI/s i have owned would get 38 and 31

Your MPG figures seem low. TI/s i have owned would get 38 on a trip
38 ???

Love to know how
31 maybe 32 would pull a very well tuned Ti up and even that is extremely good going
All the Ti's myself and the family have had have always been around the 27-29 mark on a trip
 
I once returned 36 MPG in a club Fuel Economy run! You know driving around 90 degree corners through stop signs in 4th gear on 2 wheels.
I found that I got booked a lot driving like that on a trip! :)
However I have about 15 years of my fuel usages recorded and trips were always 28 MPG.
 
  • Like
Reactions: cjl
Try whilst running, partially pinching/clamping off the hose running from the altitude "gismo" to the pump.?

If you still have your M53 distributor try putting it back in for a trial. (See Thanos post). The later Ti's had a M58. I have a near new M58, however I put my old M53 back in AND there is a big difference. We put both distributors on a test bench and there was very little difference between them. (Doubt it will fix your mixture problem though).

Other than the bits above your sooty plugs problem sounds like the big spring on the top of the pump may be incorrectly set!? (You may have ruled this out by changing pump heads)?

If no remedy drive the car over here to Australia and give us a fiddle!! Ha Ha. :)
 
  • Like
Reactions: con
BIGRR - I think the spark plugs maybe the wrong ones; as in too cold. Do you remember which ones you are using?
In any case, I have never been a fan of Lucas.
 
should be 4deg BTDC
Based on what? I actually dont know what its set to, only that its set to the mark on the timing plate. Only two marks, 0 and something else. The Haynes manual says 5deg, others i have talked with says the mark is 8deg.
 
Based on what? I actually dont know what its set to, only that its set to the mark on the timing plate. Only two marks, 0 and something else. The Haynes manual says 5deg, others i have talked with says the mark is 8deg.
What the book says is irrelevant. Different fuels, different compression ratio, etc. I set mine anywhere between 10 and 12 degrees, and it was running a lot better. It's one of the easiest things to test: Rotate counterclockwise and drive until you get the best results, then measure the timing there (and ignore the number anyway :) ). This thread gives me deja vu. I spent more than a year and a LOT of money trying to get my KF injection to run right. I finally gave up and switched to twin Webers. The side benefit is that once I decided to do that, I also increased CR, got a warmer cam, extractors etc. for a 40 bhp power bump. You said you have a V6 and box from the 604, that's an easy drop-in and a great, inexpensive upgrade. If you are loath to acknowledge defeat and intent on staying with a 2-liter and fuel injection, perhaps convert to a Megasquirt fuel injection. There are a lot of background and material sources in this forum and you will solve the problem once and for all.
 
I once returned 36 MPG in a club Fuel Economy run! You know driving around 90 degree corners through stop signs in 4th gear on 2 wheels.
I found that I got booked a lot driving like that on a trip! :)
However I have about 15 years of my fuel usages recorded and trips were always 28 MPG.
I was envious of these results, I never got more that 22 mpg with a stock Ti engine, then I realized that your gallon is 4.5 liters so we are not too far off and our speed limits in Greece are higher and enforcement far more lax. Once I hotted up the engine this number dropped to 14 mpg or lower.
 
Trying to sum up some answers to your latest comments.

The spark plugs, Champion N6Y is recommended in the Haynes manual, and also the same plugs that the dealerships in Norway used on these engines.

The distributor has barely been in use since new, so i guess its in good shape, but i could always try the old M53. But as mentioned, the timing has been set with a timing light, and it moves left (advance) as the revs rise. The car pulls fine and revs easy, so it doesnt seem like the timing is the problem.

Injectors have been checked, all OK. The electrovalve is also good.

Regarding the pump head, today i re-opened the original one, checked the new membranes and all looks good. I will re-fit this, along with the number-matching altitude corrector. The big CO screw/spring at the top of the pump-head measures 19mm, the same on all three pump-heads.

I will set everything back to a "base point", the idle screw, the enrichner screw and the butterfly. If it still gets flooded with fuel, i will have to check the timing of the pump itself. As mentioned previously in this thread, the Haynes manual is wrong regarding the distributor drive, so that was 180deg off, maybe the timing of the pump is wrong also?
 

Attachments

  • 10.jpg
    10.jpg
    564.8 KB · Views: 98
  • 11.jpg
    11.jpg
    492.3 KB · Views: 100
  • 12.jpg
    12.jpg
    690.2 KB · Views: 101
  • 13.jpg
    13.jpg
    532 KB · Views: 102
  • 14.jpg
    14.jpg
    478.5 KB · Views: 94
The car pulls fine and revs easy, so it doesnt seem like the timing is the problem.
If the spark plugs are loaded with carbon that means you have extra fuel, which takes the space oxygen would occupy and generate extra combustion, so physics says that with less combustion power is down regardless of the feel. Do you have cylinder pressures for all four cylinders? Are they around 180 psi and similar to each other? With the engine at idle, pull out one spark plug wire at the time to keep the car running on three cylinders briefly. Is there a similar drop in revs for each cylinder? The way we were checking pump operation was to disconnect fuel feed from the pump side one line at a time in a similar way we did with spark plugs. I am not sure about the safety of this method as you have fuel leakage, but it certainly gave information on pump operation.
 
Alex,

when I purchased my Ti in early 1974 it had problems with a miss up about 4000 RPM. I took the car back about 5 times before they admitted that there was a problem AND they replaced the Injection pump.
Each time the car came back it run well except for the miss. I checked the timing, plugs, etc after return of the car each time. The last time they had it on a dyno (They were sick of me whinging, Oh and I wrote to Peugeot France) Hence my figures. I don't remember what plugs though they were Bosch.

The timing 4 BTDC is Static ie turning the engine with a light across the points (not engine running)). (I gently roll/pull/rock the car along in gear).

There is a 7mm (?) hole drilled in the top flange of the gearbox bell housing. When a 7mm(?) pin/bar is dropped down the hole and the engine rotated the pin/bar will engage with a hole/slot in the flywheel. This is TDC. The timing mark on the front cover should be set/lined up to zero with the flywheel pin engaged. My front timing cover plate is marked in degrees 0-16degrees in 2 degree grads with a notch at TDC and the plate may be adjusted by slackening off the 2 bolts that clamp it to the cover.((Probably telling you how to suck lemons)). :)

I think the car will run well at 8 BTDC at higher revs but it will pull better at 4.
 
Last edited:
If the spark plugs are loaded with carbon that means you have extra fuel, which takes the space oxygen would occupy and generate extra combustion, so physics says that with less combustion power is down regardless of the feel. Do you have cylinder pressures for all four cylinders? Are they around 180 psi and similar to each other? With the engine at idle, pull out one spark plug wire at the time to keep the car running on three cylinders briefly. Is there a similar drop in revs for each cylinder? The way we were checking pump operation was to disconnect fuel feed from the pump side one line at a time in a similar way we did with spark plugs. I am not sure about the safety of this method as you have fuel leakage, but it certainly gave information on pump operation.
Yeah, and thats the issue, it gets flooded with fuel and the plugs get all sooted. I havent done a compression test after the engine rebuild, but i have tested the pump like you describe by disconnecting the fuel feeds, and also the spark plugs like you mentioned.
 
Alex,

when I purchased my Ti in early 1974 it had problems with a miss up about 4000 RPM. I took the car back about 5 times before they admitted that there was a problem AND they replaced the Injection pump.
Each time the car came back it run well except for the miss. I checked the timing, plugs, etc after return of the car each time. The last time they had it on a dyno (They were sick of me whinging, Oh and I wrote to Peugeot France) Hence my figures. I don't remember what plugs though they were Bosch.

The timing 4 BTDC is Static ie turning the engine with a light across the points (not engine running)). (I gently roll/pull/rock the car along in gear).

There is a 7mm (?) hole drilled in the top flange of the gearbox bell housing. When a 7mm(?) pin/bar is dropped down the hole and the engine rotated the pin/bar will engage with a hole/slot in the flywheel. This is TDC. The timing mark on the front cover should be set/lined up to zero with the flywheel pin engaged. My front timing cover plate is marked in degrees 0-16degrees in 2 degree grads with a notch at TDC and the plate may be adjusted by slackening off the 2 bolts that clamp it to the cover.((Probably telling you how to suck lemons)). :)

I think the car will run well at 8 BTDC at higher revs but it will pull better at 4.
Did you ever find out what was wrong with the original pump?

I never managed to find that hole on the bell housing, but was able to find TDC other ways. My timing cover plate only has two marks.

Lets see what happens when i reinstall the original pump-head with new membranes and the matching-number barometer. I will keep you updated!
 

Attachments

  • 2022-05-14_18-12-26.jpg
    2022-05-14_18-12-26.jpg
    129.2 KB · Views: 93
Did you ever find out what was wrong with the original pump?

I never managed to find that hole on the bell housing, but was able to find TDC other ways. My timing cover plate only has two marks.

Lets see what happens when i reinstall the original pump-head with new membranes and the matching-number barometer. I will keep you updated!
Never found out what was wrong with original pump.

Good luck.
 
Your MPG figures seem low. TI/s i have owned would get 38 and 31

Your MPG figures seem low. TI/s i have owned would get 38 on a trip
The first one i owned was an 1800 injection i got in UK and drove everywhere from the arctic cyrcle to the sahara dessert then shipped to Aus then i had a 71 2litre injection i bought sh here [a personal import]. I would get these MPG figures on country trips driving at the speed limits
 
I am assuming your injectors have been tested for opening pressure. Disconnect the electrovalve and see if this hesitation goes away. Is the car harder to start when warm?
Yes, electro valve could be leaking, remove it with hose connected to see?
 
Update:

I have fitted the original pump-head with new membranes and the matching barometer/altitude corrector.

The main screw on the pump head measures 19mm from top to bottom (photo). I set the idle adjusting screw to about 10mm from bottom of the bolt-head to the top of the securing nut, and started with the enrichner screw ca one round outside the nut. I also adjusted the butterfly again with the light-gap according to the manual.

Started right away, and was idling around 1100rpm for a bit. When it reached operating temperature, it fell down to about 700rpm and no matter what i do, i cant get it higher. Adjusting the idle screw has no effect, unless i adjust the butterfly with to big of an opening, and the flat-spot is back, as if it wants do die out when i rev it, occurs somewhere between 900-1100rpm.

And one other thing, its coming smoke from the dip-stick. As mentioned before, all hoses are new, including the ones related to the crankcase ventilation, filter included.

Again, i really appreciate all of your tips.
 
Top