v70 running problem. tried everything

james-v70 · Post by **james-v70** » 04 Dec 2010, 16:54

hi guys i new on here. i have just bought a 2455cc 10v manual v70. but when the car warms up it doesnt allow me t have full throttle. it bounces betweeen 2 and 4 thousand revs. i have no fault codes, the car has had new plugs, leads, dizzy cap, rotor arm,, coil pack, temp sender at the thermostat and the ecu to try and solve the problem. i have also tried disconnecting the o2 sensor, the cat, the fuel pressure regulator and tried running with the fuel cap off. cylinder compression is good and it uses no oil or water. please help..
james

Post by **precopster** » 04 Dec 2010, 17:18

You said "when the car warms up doesn't allow me to have full throttle"

When the car is cold, all is well?

james-v70 · Post by **james-v70** » 04 Dec 2010, 17:42

well it feels like it has a very slight miss when cold too but is much more noticeable when warm. when warm if i rev when parked up, floor the throttle and the revs will go up then drop then go up and just bounce around

ctw · Post by **ctw** » 04 Dec 2010, 18:35

Very much a greenhorn here but from your description it sounds fuel related.?

lucky phil · Post by **lucky phil** » 04 Dec 2010, 19:55

hi.
try clamping fuel return line and see if it runs better.i have fuel pump issuses and it works ok when i do that,have ordered new pump. i am also new at this but was told to try that by spare parts man.hope its ok.lucky phil

Post by **JDS60R** » 04 Dec 2010, 19:58

When the car is idlinge does it go up and down between 2000 and 4000 rpm?

Does your car have a turbo?

Post by **jblackburn** » 04 Dec 2010, 20:25

Try unplugging the mass airflow sensor just after the air filter box and going for a drive. Does the car act any better?

This will set a code, but it can easily be reset.

james-v70 · Post by **james-v70** » 05 Dec 2010, 01:50

i will try clamping the fuel return tomorrow when i go into work.
the car is non turbo and when its idling it sits perfect at 900-1000 rpm.
ive tried unplugging the maf even tho its new, but it made no difference.
anymore help would be greatly apreciated

lucky phil · Post by **lucky phil** » 05 Dec 2010, 22:36

hi. my car would run rough at all speeds in the end ,would go ok for a few ks then play up.i think my non return valve in the pump was faulty as would not maintain pressure in the system , ,lucky phil ,good luck