Peugeot 1.6 cti 1990 cutting out

[Karl Okah 0]

Car just cuts out when hot. Revs drop and engine stops. Changed the ignition amplifier and it still happens BUT seems to make it easier to restart now! Small mercies. At one point a saw smoke/steam/ exhaust coming out from under the bonnet on restarting. What next? AFM? Ignition module? 

[Richard309Sri XU5JA 205GTi 7]

to kick off, have you tried adjusting the throttle body air bypass screw?, as per setting the warm idle in Haynes 

 

&

 

with ref to 

 

[sunshinestarbear 0]

I haven’t tried that. Do you think that would work? The engine just stops completely. Then I have to wait a minute before it will restart. Sometimes I turn the ignition key off and coast with the clutch down and re-engage the engine like a “bump start” and that will start it, but that’s less common. It’s only with a hot engine too. 

[Richard309Sri XU5JA 205GTi 7]

In my opinion I reckon that's worth checking as above.

 

&other common problems worth checking are/could be:-

1. low fuel pressure - check fuel pressure using pressure meter 

 

2. faulty fuel pressure regulator - check using hand vacuum pump 

 

3. vacuum leaks - check all hose joints  and jubilee clips

downstream of the air flow meter - so you have unmetered air into the mixture 

 

4. timing issues - incl. distributor advance weights.mechanism not working 

check using a dyno. strobe light timing gun. 

 

would be worth checking static timing also in my opinion. 

 

5. I am not sure about this in terms of problems when hot as mostly I had problems with this from cold but maybe worth checking the ETS - ECTS - engine coolant temp sensor is ok. Its NTC - negative temp. coefficient. 

But if it is not right it could still mess up the hot running/hot idle in theory. Blue plug two pin. 

 

If it stalls when hot it's got to be the mixture is too thin not enough fuel, ? 

I can't say I have had this problem and seen this for sure though. I had problems with overfueling from cold. 

Then the plugs were drowned and you can see each time the oil-petrol mix over the plugs. I cant see it would overfuel when hot if it starts when cold. 

 

You might be able to get a clue also from any deposits on the spark plugs? 

 

 

[sunshinestarbear 0]

Thanks for all that. I’ve sourced a second hand AFM even though it probably isn’t that - the old one looks like it was been cracked open and re-glued. If that fails then I will probably hand over to an expert as I’ve changed a lot of the ignition system. As is common in Pugs there is an old alarm system and spaghetti wiring so I may see if that could cause a problem. As a query does the ignition module in the base of the distributor ever fail? 

[PhilNW 40]

Agree with checking fuel pressure, hot engine also means fuel pump has been working hard. Dont forget the pump is now in the order of 30 years old.

 

What makes you think it is electrical, does it start OK when cold?

Edited October 30, 2021 by PhilNW

[sunshinestarbear 0]

I think it’s electrical because when it happens the Rev counter, which feeds off the distributor output drops. It reads zero even on turning the engine over to restart. It only reads again when it will start. My current money is in the old immobiliser from the 90’s

[PhilNW 40]

Have you got a spare spark plug, take one of the leads off and put the plug in it and let the plug earth out on the engine.  Do you get any sparking at the plug when turning over?

 

 

[sunshinestarbear 0]

Yes. I get a good spark. And it runs really well. Until it cuts out suddenly and unexpectedly usually when it’s warmed up. 

[PhilNW 40]

Have you still got a good spark when it stops? or no spark at all?

 

 

How long before it starts again?  A minute or two or do you have to wait for the engine to cool?

[sunshinestarbear 0]

I’m assuming no spark and no ignition when it stops. Yes, a minute or two and it starts again

[PhilNW 40]

Can you establish yes or no spark?             (as per the method I mentioned above)

 

If it is the pump a minute or two might be sufficient for things to "cool down" and be good to go again.

 

The same applies to electrical component as well