New Owner - Help/advice please

[SirSagalot]

I am the new and proud owner of a 99 4.0 Chimaera. All standard until I stuck Clive's Y piece on, put ACT coolant hoses on, changed the Plenum elbow and the ACT Trumpets (although my mate did that). All was good until the last weekend when the engine started to surge at idle and cut out going round a corner. So, did some research and spoke to my mechanic buddy and changed the stepper motor. All was great, took it for a run and then just as I got home it cut out. It restarts fine but won't hold the idle. I've had a look on the forum but couldn't find anything that leapt out.

Any advice would be really appreciated as I have already taken too much of my mates time. Thanks.

[SirSagalot]

I got a new one from Clever Trevor and fitted it. Given the cost of it I think it's am genuine part. Thanks

[SirSagalot]

Thanks. Is there a certain way of doing that?

[SirSagalot]

Thanks - I'll try that. The Stepper Motor was an original part and cost around £50. Appreciate all the advice.

[SirSagalot]

Thanks again all. I will try all the above and let you know if the problem is solved. All a big learning curve for me so appreciate all the advice.

[SirSagalot]

Well Clever Trevor really is Clever. After spending £65 (checked the invoice) on a new stepper motor that caused me to post on the forum, I have cleaned and put the old one back and she seems to be ok.. The revs idle high for a few secs when engaging the clutch and then drop back to around 900. A much better situation than I was in 24 hours ago. So I am going see how things go for a while. Appreciate all the input and hopefully I can one day assist others (albeit unlikely).

[SirSagalot]

Thanks. Andy at APM fitted the Y piece as the manifold gaskets needed changing and the pre cats were removed so I don't know the answer. I've had the Y piece on for a few hundred miles now and the problems only started after the breather hoses and trumpets were changed.

[SirSagalot]

Thanks Anthony. Hope you are well.