Jump started, now running rough

[Ranga]

The old man just jump started his TD5 after a flat battery from no use in a couple of months, and as he drove it around the block, it was running pretty rough. Idling was fine, but on acceleration spluttering, missing and overall didn't sound great. Understand, he's certainly no mechanic, and this was the best description he could give.

Any ideas what might be the problem? Could not driving it for so long, and not giving it a good enough test run be the issue? Would giving it another test drive be an option?

[SiddersC]

Low battery voltage?
Old fuel?

[Eevo]

Would giving it another test drive be an option?

whats wrong with holding the revs at 2000rpm while in the driveway?

that way if something happens, your still in your driveway and not somewhere else

[Disco Muppet]

Could it have gone into limp mode from the jump start?

[Ranga]

Low battery voltage?
Old fuel?
That's my thoughts.

Could it have gone into limp mode from the jump start?
That's what I was more worried about

[disco2_dan]

Did you use normal jump leads or the safety type

[Ferret]

Safety type? What's different between 'normal' and 'safety' jumper leads?

[Eevo]

Safety type? What's different between 'normal' and 'safety' jumper leads?

the cost, nothing else

[clubagreenie]

At least if it started there's nothing fried absolutely.

While there's a limp mode (for instance, in the V8 if a MAF fails the auto can go nuts, cut fuel, add fuel and generally be unpleasant) there's no setting to turn it off. It seems to be based on sensor input and what the ECU likes and doesn't like.

[Yorkie]

disconnect the battery neg and see if that resets it.
also a new fuel filter would not harm if been sitting a while.

[disco2_dan]

Safety type? What's different between 'normal' and 'safety' jumper leads?

Normal one are the traditional type, fine for carbie cars but not as great for efi, the safety one have a breaker in line so if there is a surge you won't try anything