Need help diagnosing engine running rough

[SalvadorP]

Originally Posted by Laird Scooby

Proper carb cleaner won't leave a residue.

I see.
What should I use to clean distributor? Contact cleaner?

[TonyS9]

Originally Posted by SalvadorP

I see.
What should I use to clean distributor? Contact cleaner?

Just a solvent like white spirit to remove the oil and dirt. It shouldn't be difficult to clean like the combustion products on the throttle body so you don't need "intake" or "carb" cleaner.

[Clan]

Originally Posted by SalvadorP

[YOUTUBE]https://youtu.be/1UhOnEHIB6s[/YOUTUBE]
https://youtu.be/1UhOnEHIB6s

My car runs rough and vibrates a lot at idle and even more at 1500rpm. I've changed plugs, cleaned PCV, changed all filters, ran injector cleaner, etc.
The car does have a crack both on front muffler and cat, but why would it only vibrate at idle and 1500?
I'm suspecting a dirty MAF or distributor issues but i really dont know. What do you guys think?

Seems worse when it rains and today the engine cut out in the morning while idling cold.

If it seems worse in the damp suspect HT Plug leads, what happens when you drive the car is it still jerky or does it drive fairly normally? , Clean the distributor cap by all means , but make sure it is a volvo Bosch one , those Bosch you buy elsewhere are inferior and some previous owner could have fitted one . what does the inside of the distributor look like? can you see any signs or arcing ? ( black zig zag lines near the terminals inside the cap . what kind of finish is inside the cap ? Is it shiny Lacquer or matt brown ?
The exhaust leaking from where you say wont affect the running at all . I suspect an Air leak , have any Air hoses cracked on the Inlet manifold ?

[SalvadorP]

Originally Posted by Clan

If it seems worse in the damp suspect HT Plug leads, what happens when you drive the car is it still jerky or does it drive fairly normally? , Clean the distributor cap by all means , but make sure it is a volvo Bosch one , those Bosch you buy elsewhere are inferior and some previous owner could have fitted one . what does the inside of the distributor look like? can you see any signs or arcing ? ( black zig zag lines near the terminals inside the cap . what kind of finish is inside the cap ? Is it shiny Lacquer or matt brown ?
The exhaust leaking from where you say wont affect the running at all . I suspect an Air leak , have any Air hoses cracked on the Inlet manifold ?

Previous owner always brought the car to Volvo and i have a maintenance sheet. I can check when it was changed last time but I'm sure it's an original Volvo part.
Car does it cold or hot. Vibrates at idle with a small misfire and idles at about 850/950. Then it stops and vibrates again at 1500.
I'm yet to open the distributor. Want to do it today but my knee is acting up, not sure if I'm gonna be able to. Will take pictures.
I can't find any air leaks, that was my first suspicion. My i should change the hoses that looks holder, but non looks cracked though. Some on the intake look like the rubber on the outside is starting to crumble, but no enough to leak.

[Laird Scooby]

Originally Posted by TonyS9

Just a solvent like white spirit to remove the oil and dirt. It shouldn't be difficult to clean like the combustion products on the throttle body so you don't need "intake" or "carb" cleaner.

Don't use white spirit, it leaves an oil residue that will attract dirt and cause tracking. Use something like methylated spirits, isopropyl alcohol or similar solvent that evaporates leaving no residue.

[SalvadorP]

Originally Posted by Laird Scooby

Don't use white spirit, it leaves an oil residue that will attract dirt and cause tracking. Use something like methylated spirits, isopropyl alcohol or similar solvent that evaporates leaving no residue.

Thx. Will check now if i can even take it off. Seems tight back there.

[SalvadorP]

Originally Posted by Laird Scooby

Don't use white spirit, it leaves an oil residue that will attract dirt and cause tracking. Use something like methylated spirits, isopropyl alcohol or similar solvent that evaporates leaving no residue.

The other 2 seem easy but had to get creative with my tools to take the left one out. Seems super oily. That's not normal is it?

https://imgur.com/a/coh3jvx

[SalvadorP]

Cap is definitely oily. Doesn't look like it's cracked though.
Shouldn't rotor come right off? Do i have to twist it or pry it off?
https://imgur.com/a/7LJIhhK

[Clan]

Originally Posted by SalvadorP

Cap is definitely oily. Doesn't look like it's cracked though.
Shouldn't rotor come right off? Do i have to twist it or pry it off?
https://imgur.com/a/7LJIhhK

dont pry it off or you will break it ... wangle it off by hand as gently as you can or clean it in place .
Does it go up to 1500 rpm on its own?

[SalvadorP]

Originally Posted by Clan

dont pry it off or you will break it ... wangle it off by hand as gently as you can or clean it in place .
Does it go up to 1500 rpm on its own?

Yeah, it's not coming off. I'll clean it there. Looks a bit gone, but i don't know how big this copper "lip" is supposed to be.

Answering your question, normally no. It has done that a few times when was raining, including the other day. It jumped probably as high as 2000+. But only did that a few times. If it's related to rain and humidity, it's normal, sunce we are having severe draughts.


Rotor pic:
https://imgur.com/a/GGmEwuR