engine sputters at certain point when accelerating

hooky72 · Post by **hooky72** » 20 Apr 2011, 17:26

Hi,

I have an s40 1.9d Se 2002 right hand drive.(u.k)

I am getting what seems like a blocked fuel line when my accelerator is at a certain point, engine splutters, although when I 'floor it' the spluttering stops.

please help

Post by **kcodyjr** » 21 Apr 2011, 00:15

Sounds like a bad throttle position sensor, but before you go replacing things, check your air filter.

Also, double check that when you say floor, you really mean on the floor - does it behave at 7/8 throttle?

hooky72 · Post by **hooky72** » 21 Apr 2011, 17:03

yes i mean on the floor and soz but what does 7/8 throttle mean?

Post by **kcodyjr** » 21 Apr 2011, 19:21

7/8 would be about an inch above the floor. It's not a precise measurement.

The key is a distinct change in behavior when you get all the way down. I'm not 100% sure how the Volvo TPS works internally, but usually when a sensor is picking up a range of possible values, a variable resistance is somehow involved. The upshot is they're more whacked out at the middle of their range than at the bottom or top of it - in this case, decent idle and wide-open, but inaccurate detection anywhere in the middle.

kcjones · Post by **kcjones** » 21 Apr 2011, 21:52

Spark plugs, just in case. Also try high(er) octane fuel, and some Techron fuel treatment. I'm not saying it's not TPS related, but to be sure, go down "the list".....

Wires, distributor cap/rotor, plugs, air, fuel, etc.

dw6248 · Post by **dw6248** » 30 Apr 2011, 07:39

Definitely try the spark plugs first. I had similar symptoms last summer with my 02 V40 and it was the plugs.