My Tigra, which I've had about two weeks, has developed a fault. It drives fine, it starts fine, and it runs great until it's warm enough for the air injector pump to cut out. Then the engine becomes lumpy at tick over and up to about 2000rpm it's not right. Above that and it's fine. I've done the usual stuff: plugs, leads, checked that I have a good spark, compression test, carb cleaner in the air inlet pipe etc. I've asked other people, but they don't really know or they guess with a stab in the dark. If I ask a garage I won't get an answer unless I book it in with no budget limit.

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