TiAg

Update. It was the injector! Ended up replacing all 6 though. no problems since.

Just to add we narrowed it down to no.6 cylinder. Spark is good when it decides to play up. and compression is a perfect 180psi.

So it's gotta be fuel injector or related to what drives it, ECM?. Or something else is telling cylinder 6 not to inject fuel. Crankshaft sensor? 

On 3/7/2015 at 6:35 PM, Peeved said:

Have an 04 hilux SR5 3.4l with 170,000 km on the clock that has been a dream until it developed a problem recently. Runs ok when first started, then starts to run rough after warmed up or turned off and restarted.Then it starts to shudder especially at idle, and lacks power,particularly on hills. Have just had plugs and leads replaced,Ignition coils checked and okayed. Cylinder pressures all good,and injectors cleaned [2 were borderline].After this work was done [$750.00 worth] it ran fine for a few days and then back to square one. It is actually a bit worse now in that it used to come and go, meaning after a while on a long trip it would suddenly come good. Now it runs for 5 mins. and the problem comes on and remains until turned off for a length of time. There are no warning lights on at any stage. Not prepared to go to Toyota re.this problem until I win tattslotto due to previous experience, and none of the mechs. I have talked to have a clue, just a matter of elimination and wallet reduction.Hoping for some help please.

Sorry for bumping an old thread. I have exact same issue as described done some of the same work plugs,Leads,Coils, Fuel filter.

Almost seems like it shuts an injector off.  For a test when its running good i pulled one injector plug while it was running and i acted sounds the exact same as when i plays up.