Thread: disco 3.5 v8i running rough

Originally Posted by Quiggers

Hi all,

The ongoing fun and games....

A while back I cleaned out the fire trap and its lines, the rocker covers and other things. Last few weeks have seen a new(er) fuel pump, a new fuel filter and a clean out of the fuel lines. Today, new plugs and leads and a clean of the dizzy, which seemed okay.

But it's running rough. Idles okay, select drive, accelerate (slowly) and it kinda dies a bit, then picks up. At 2500rpm I hear a distinct clatter noise (but not a tappet noise), haven't heard this sound before.

Injectors? Maybe? Clean the MAF? Everything was quite okay until the saga of the fuel pump......

What do you think?

BTW:: Whats the $$$ on cleaning up the injectors? Or can I do it?

Cheers, GQ

Might just be cheaper to buy new injectors bosch do a replacement for the 3.5 only a couple of hundred$$$ a mate of mine did his a couple of years ago

You should really do an injection diagnostic.
But here are a few suggestions
1 clean the MAF by spraying elctronic cleaner in the hole inside.
2 Check the connector on the MAF, clean the contacts with a small file or emery.
3 check that the Throttle Position Sensor is working properly. The symptom you describe ie a flat spot accords with a bad TPS. The TPS should have an even and uninterupted decrease in ohms when turned through its range with ign off.
4 Check the connections on the ECU temp sensor and clean. Check that the sensor reads 700 Ohms or less at over 80C, ie normal operating temp.
5 low speed miss is also symptom of old rotor and dizzy cap with too big an air gap. Suggest replace.
Regards Philip A