504 Stalling Issue

James Gelido

James Gelido

Active member
VIP Paid Subscriber
Fellow Frogger
Joined
Jun 16, 2018
Messages
323
Location
Sydney
Hi everyone,

Have a slight issue with our 504. The car stalls when stopped on a downwards slope, when in 1st, 2nd and 3rd gear. The car is automatic. The stalling seems to be more frequent at night, with the lights running. The idling straight away drops when at a stop and in gear. My friend suggested the timing, although I have experimented with advancing and retarding the dizzy, and tried to adjust idle mixture, but same result. Also have cleaned the main jets in the dual carbies, checked for sediment, checked vacuum leaks, and transmission level, all seem okay. Has anyone had any similar issues?
 
James Gelido said:
Hi everyone,

Have a slight issue with our 504. The car stalls when stopped on a downwards slope, when in 1st, 2nd and 3rd gear. The car is automatic. The stalling seems to be more frequent at night, with the lights running. The idling straight away drops when at a stop and in gear. My friend suggested the timing, although I have experimented with advancing and retarding the dizzy, and tried to adjust idle mixture, but same result. Also have cleaned the main jets in the dual carbies, checked for sediment, checked vacuum leaks, and transmission level, all seem okay. Has anyone had any similar issues?
Click to expand...
James do your dual carbs have an idle solenoid and power feed broken off or left off? I dont know 504s but my old Fiat had a similar issue.
 
dimistyle said:
James do your dual carbs have an idle solenoid and power feed broken off or left off? I dont know 504s but my old Fiat had a similar issue.
Click to expand...
Yep, its dual carb. I don't think it has either tbh. How did you get around your Fiats issue?
 
Hi James,
no experience of 504's or automatic Pugs but from your description it has to be increased load on engine =stall. Assume the Auto box has 1-2-3 then "D"? and this doesn't happen in "D"?? - what about Reverse?

Generally (from my 505 experience) be suspicious of any rubber vacuum / breather / bypass pipes - they can look OK but be so aged & brittle as to be almost porous (I'm attempting to replace the 505's incrementally with silicone examples). One other thing I can recall from years back (don't remember what make or model) - and its not good news - was a car with a crank thrust bearing so worn that every time it went up a steep hill the crank moved back & stuffed the timing! Difficult to check for 'insitu' but maybe try setting the timing when its on a steep downslope, take for a drive then recheck on the flat?

Other than that have you tried increasing idle speed a tad then checking if it still happens? Have you removed a plug after prolonged idle when warm to check colour? (mixture too rich or lean?).

Regards,
Rob
 
Hi James

Does the car idle rough before stalling? Can you start the car straight away after stalling? Does it start easily?

It could be a loose electrical connection or the insulation on a wire has warn through and it is earthing out.

I'd be checking all electrical connections at the coil, distributor (take cap off and check points wires), check plug leads.

Mine cut out once due to number 4 ignition lead rubbing through the insulation in the oil bath support.
 
^ Good point, and good thinking.
There may not be enough spark, and he is just not noticing it in everyday driving. That scenario fits his symptoms....at night with the lights on, the alternator causes more drag on the engine's revolutions. And having it in gear produces a bit of drag too, at any time.

But one drag on top of the other will then cause it to stall, rather than the usual culprit of a clogged idle jet.

The coil may be getting a bit old. Recently with one of my cars, I replaced the coils (there are two in mine) and the difference in power and general running was quite substantial.

Then of course there is the common issue of the 504 spark plug insulators not insulating properly, but you'd think it would chug a bit and run on three cylinders if that were the case.
 
Last edited:
baldrick56 said:
Hi James,
no experience of 504's or automatic Pugs but from your description it has to be increased load on engine =stall. Assume the Auto box has 1-2-3 then "D"? and this doesn't happen in "D"?? - what about Reverse?

Generally (from my 505 experience) be suspicious of any rubber vacuum / breather / bypass pipes - they can look OK but be so aged & brittle as to be almost porous (I'm attempting to replace the 505's incrementally with silicone examples). One other thing I can recall from years back (don't remember what make or model) - and its not good news - was a car with a crank thrust bearing so worn that every time it went up a steep hill the crank moved back & stuffed the timing! Difficult to check for 'insitu' but maybe try setting the timing when its on a steep downslope, take for a drive then recheck on the flat?

Other than that have you tried increasing idle speed a tad then checking if it still happens? Have you removed a plug after prolonged idle when warm to check colour? (mixture too rich or lean?).

Regards,
Rob
Click to expand...
G'day Rob, thanks for the reply! I have gone through all the hoses with a fine tooth comb, also replaced the vacuum hose to the dizzy with a new one, no change. The car is okay on idling and reverse, seems to only cut out on '3' when stopped down a hill. Sometimes, it will also stall on '1' and '2' if I have lights running and stopped. Have increased idle, but for to compensate the low revs on 3rd, I have to put the revs so high that it will clunk into gear from 'P'. I don't think it is a crank thrust bearing, as no change uphill, on the contrary, it seems to run better. Also, removed a plug but the mixture seems to be fine. I'm really stumped. Only thing I can think of is maybe I got the timing slightly off? 🤷‍♂️
 
Pug72 said:
Hi James

Does the car idle rough before stalling? Can you start the car straight away after stalling? Does it start easily?

It could be a loose electrical connection or the insulation on a wire has warn through and it is earthing out.

I'd be checking all electrical connections at the coil, distributor (take cap off and check points wires), check plug leads.

Mine cut out once due to number 4 ignition lead rubbing through the insulation in the oil bath support.
Click to expand...
Yes it does, and the car starts fine after stalling. Relatively easily. My horns give off a very off 'meep' and I suspect it could be earthing out. Could this be a culprit? I checked the connections at the coil and dizzy, but Earth wires seem to have been replaced at some stage, as appear okay.
 
Try replacing the coil with a known good secondhand one, or invest in a new one. They don't last forever.
 
Appeared to have solved the problem! Thanks to 'Pug72s' comment, I started to think why it would have weak spark? :unsure: After testing the coil ohms, everything checked out. Checked the wires, all seemed to be in pretty good condition, checked the spark plugs wires, all good, took a spark plug out, no carbon build and was not wet 🧐 ...... This is where it gets interesting ...... I then proceeded to re-insert the boot into the plugs head, this time with a tight push, and heard a 'pop'. I did not realise that the boots require a push into the plug heads (see photo). Leads going into the head had a very loose connection, virtually floating, as I had mucked around with them before. Popped them all in properly, and voila 🥂🍾 She runs fine and put her on a steep slope on '3' with lights on, at a stop, and she stays alive. Increased revs a bit and now idles okay in '3'. Might try mucking around with the dizzy later to tweak the timing,

Rookie mistake, and sometimes it's best to go to the basics. Thanks everyone!
 

Attachments

  • Spark Plugs 504.jpeg
    Spark Plugs 504.jpeg
    234.6 KB · Views: 75
James Gelido said:
Appeared to have solved the problem! Thanks to 'Pug72s' comment, I started to think why it would have weak spark? :unsure: After testing the coil ohms, everything checked out. Checked the wires, all seemed to be in pretty good condition, checked the spark plugs wires, all good, took a spark plug out, no carbon build and was not wet 🧐 ...... This is where it gets interesting ...... I then proceeded to re-insert the boot into the plugs head, this time with a tight push, and heard a 'pop'. I did not realise that the boots require a push into the plug heads (see photo). Leads going into the head had a very loose connection, virtually floating, as I had mucked around with them before. Popped them all in properly, and voila 🥂🍾 She runs fine and put her on a steep slope on '3' with lights on, at a stop, and she stays alive. Increased revs a bit and now idles okay in '3'. Might try mucking around with the dizzy later to tweak the timing,

Rookie mistake, and sometimes it's best to go to the basics. Thanks everyone!
Click to expand...
Strewth James, you had me worried there for a while. 😥Well done all. Remember though............ "It's French!" 🇫🇷😉
 
Haha...always blame someone else James.

They are pretty simple motors and normally a process of elimination with troubleshoot most problems which is why I still drive mine everyday.
 
Okay, my apologies, I may have celebrated a tad early. Although it did help, it did not solve the issue. Once again, was on a steep gradient, with lights on after a night drive, stopped, and the beast stalled! 🤬 Viva la bloody FRANCE!

The only thing that seems to help is if I pull the choke a bit more than halfway, the engine will idle the way it is supposed to, and does not stall! I guess the issue would be fuel starvation? It's a new fuel pump, and idles fine when on a flat, floats are good, I have tried mucking around with the mixture screw, with not much success. The revs barely change when I screw the mixture screw in or out. In fact, I've had it screwed all the way in, and the motor still ran the same as it was 5 rotations before. Any suggestions people?
 
Just out of interest, being on a gradient, was the front of the car downhill or uphill?
 
Hi James,

from your description I'd say its likely to be a partially blocked fuel line. I had hours, if not days of fun when I first got my 404 with this - it would splutter to a halt at the most inopportune moments - often would go again if left alone for a while. I 'rodded out' the line with a piece of wire a few times - never really cured it until I replaced the line with a stainless steel one (there's a post I did about that on here somewhere). In the interim I took out the tank, drained, filled with some gravel and agitated the crud & rust off the inside which I'm sure helped too (all manner of debris came out the tank when I removed it - even a plastic handle of something somebody dropped in there). Those fuel pumps don't have much grunt on the suction side - doesn't take much to overwhelm them.

Regards,
Rob
 
baldrick56 said:
Hi James,

from your description I'd say its likely to be a partially blocked fuel line. I had hours, if not days of fun when I first got my 404 with this - it would splutter to a halt at the most inopportune moments - often would go again if left alone for a while. I 'rodded out' the line with a piece of wire a few times - never really cured it until I replaced the line with a stainless steel one (there's a post I did about that on here somewhere). In the interim I took out the tank, drained, filled with some gravel and agitated the crud & rust off the inside which I'm sure helped too (all manner of debris came out the tank when I removed it - even a plastic handle of something somebody dropped in there). Those fuel pumps don't have much grunt on the suction side - doesn't take much to overwhelm them.

Regards,
Rob
baldrick56 said:
Hi James,

from your description I'd say its likely to be a partially blocked fuel line. I had hours, if not days of fun when I first got my 404 with this - it would splutter to a halt at the most inopportune moments - often would go again if left alone for a while. I 'rodded out' the line with a piece of wire a few times - never really cured it until I replaced the line with a stainless steel one (there's a post I did about that on here somewhere). In the interim I took out the tank, drained, filled with some gravel and agitated the crud & rust off the inside which I'm sure helped too (all manner of debris came out the tank when I removed it - even a plastic handle of something somebody dropped in there). Those fuel pumps don't have much grunt on the suction side - doesn't take much to overwhelm them.

Regards,
Rob
Click to expand...
Click to expand...
Hey Rob,

Thanks for the reply! I'll look into it, but not too confident this is the issue. The car runs fine up hill and starts when parked up hill. If it was a suction problem, I assume the car wouldn't start even uphill?

James
 
You must log in or register to reply here.
Top