Engine not starting when warm

BX Tech talk
MillesimeEnjoyer
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Posts: 15
Joined: Mon Jan 19, 2026 2:17 pm
Location: Herwen
My Cars: Citroen BX 1.6I Millesime from 1992
Matra Simca Bagheera Jubilee from 1979 (work in progress)
x 6

Engine not starting when warm

Post by MillesimeEnjoyer »

Hello!

Ive become a regular here it seems! :lol:

So, problems. Again.

I have a Magnetti marelli monopoint system on my BX 1.6 from 1992.

There is a sound comparable to throttle body noises from weber carbs or any other dcoe from the engine, like little pang pang noises. Personally i think its a gasket (or lack there off) between throttle body and intake manifold. Thats causing that noise i think, false air?

Also, the engine refuses to start up when its warm/hot. I have to turn the key approx 30 seconds before it barely sputters alive. A strong fuel odor is present when it finally starts, is it drowning itself upon starting? And if so, what things do i have to look for to fix that isseu.

At least gas mileage has improved a bit since replacing the head gasket, and it still starts when the engine is cold.

I will be replacing the oil, coolant and oil filter this weekend and cutting the filter open to observe it.

No issues other then those!

Any input is greatly appreciated, and thank you all for suporting a newbie like me to the BX! [-o<
MillesimeEnjoyer
New Member
Posts: 15
Joined: Mon Jan 19, 2026 2:17 pm
Location: Herwen
My Cars: Citroen BX 1.6I Millesime from 1992
Matra Simca Bagheera Jubilee from 1979 (work in progress)
x 6

Re: Engine not starting when warm

Post by MillesimeEnjoyer »

I think ive found the problem with the not starting when warm.

The rubber seals by the injectors have dried up around the injector. This causes fuel to leak by the injector and into the engine, thus drowning it.

1 problem solved :)
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Jaba
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Re: Engine not starting when warm

Post by Jaba »

I was thinking that it was the absence of the throttle housing gasket was causing a leakage of air into manifold thereby weakening the mixture and affecting the hot starting.
The Joy of BX with just one Citroën BX to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.
MillesimeEnjoyer
New Member
Posts: 15
Joined: Mon Jan 19, 2026 2:17 pm
Location: Herwen
My Cars: Citroen BX 1.6I Millesime from 1992
Matra Simca Bagheera Jubilee from 1979 (work in progress)
x 6

Re: Engine not starting when warm

Post by MillesimeEnjoyer »

I am quite the idiot =D>

Guess i did not plug the thermo sensor back in when reinstalling the head! Silly me #-o

I saw the loose connector and thought to myself: Hey, that looks inportant. One look with the camera behind the block later and found a green connector!


Fixed high idle and not starting when warm :D

Everyone has their moments!