RPM fluctuating after using dipetane

m.t.1.0.1

hi. my car was running fairly ok but not perfect. there was a bit of a smell of fumes coming off it as it had not been used much, but it was driving alright. i got a litre of dipetane and put a small amount into the tank this evening . i mixed it as advised on the bottle. i took it for a drive and all was fine until i got back home. i left the car running and noticed the rpm starting to fluctuate. it started to rise to about 1500rpm then drop to 500. as it dropped it began to rise higher until it started to idle between 3500 and 2500 rpm. i left it sitting for about 10 mins but it didnt level out so i turned off the engine. i then started it up again and the revs were gone back to fluctuating between 500 and 1500rpm. i decided to take it for a spin and it was very sluggish to drive. after about a mile it felt that it was about to cut out so i pulled into a junction to turn around an go home. as i turned the car cut out. i started it up again and drove it home as it stuttered and choked. i turned it off and half afraid to start it now again. its due a nct so thats why i said id try this product. does anyone have any ideas what the problem might be? cheers

I don't think it's the Dipetane. That's just hydrocarbons. ODB scanner maybe? Could be a lot of things. Vacuum, throttle sensor, MAFF, intermittent spark...

m.t.1.0.1

thats what i was afraid of. its strange though that car was trouble free until now. i wondered was it that the dipetane changed the composition of the fuel and was confusing the car!!!. cheers

shedweller

m.t.1.0.1 wrote: »

thats what i was afraid of. its strange though that car was trouble free until now. i wondered was it that the dipetane changed the composition of the fuel and was confusing the car!!!. cheers

Your engine is not confused so dont worry about that. What is more likely is that a lot of carbon in the head and valves has dislodged and is messing up the combustion. The injectors could also be affected the same way. If it was me i would go for a spin on a motorway in 4th to keep the rpm up a bit to help clear out whatever has dislodged.
But dont do anything till you get a few more opinions!

m.t.1.0.1

shedweller wrote: »

Your engine is not confused so dont worry about that. What is more likely is that a lot of carbon in the head and valves has dislodged and is messing up the combustion. The injectors could also be affected the same way. If it was me i would go for a spin on a motorway in 4th to keep the rpm up a bit to help clear out whatever has dislodged.
But dont do anything till you get a few more opinions!

Thanks a mill. They were along the lines of what I was hoping for. Just wanted to see if anyone had a similar experience. It all would seem to make sense considering the car was ok beforehand but you're right it's better to wait for other opinions. Thanks again

shedweller

shedweller wrote: »

If it was me i would go for a spin on a motorway in 4th to keep the rpm up a bit to help clear out whatever has dislodged.

Ah the Italian service.

Vacuum leaks are most prominent at idle.

shedweller

Sir Liamalot wrote: »

Ah the Italian service.

Vacuum leaks are most prominent at idle.

True dat. Worth a look around OP.

Capt'n Midnight

Sir Liamalot wrote: »

Ah the Italian service.

LOL back in the day

And removes carbon from the points.

djpbarry

Moved from S&EI.

biko

Fluctuating rpm is called hunting. It's kind of like it is "breathing".

What car model and year is this?

m.t.1.0.1

hi. volvo v40 04. its running fine now again. gave it a good drive and problem seems to have cleared. tis actually running better than ever, and fume smell practically gone........ dipetane??