[rick1970]

A friend has a H25 GV that has developed a intermintant surge problem. It won't do it while I have my butt in the seat, so just going off her description that its more of a surge than a miss.

Usually higher in the rev range, usually under load, usually at hwy speeds, and usually after its been running for a while. Around 260k on the clock.

Has thrown no fault codes, and check engine light doesn't come on when its doing it.

Has new air filter, plugs and fuel filter. Is always run on 95 fuel.

The new fuel filter may have made some difference, the old filter certainly some some degree of crud in it.

The only obvious fault I can find is one of the bolts that retains one of the coils is very loose in the cover, mostly stripped thread. All coil electrical connections are clean and tight. All coil resistances read the same within reason.

99% chance this will be a love job on my behalf as far as parts are concerned, so would rather only replace whats necessary.

Dying fuel pump maybe?

Any ideas?

Cheers
Rick