Hi my mates RX7 is pretty stock engine wise, blow off valve New AMEMIYA Intercooler down pipe free flow exhaust and apexi intake.
He has had and HKS boost controller hooked up as well.

It run's fine but as soon as you want to take off there is no 1st turbo response, if you watch the boost gauge it goe's to zero until 4000 - 4500 then get's boost when the second turbo comes on.

He was told it was the turbo control solinoid so we replaced that and it did nothing.

Is this a common problem? Any Ideas what could be causing it?

 

How much boost are you getting at 4000-4500? By has had you meen past tence, check all your lines.

 

Check to make sure your lines to the charge control valve are hooked up correctly and not leaking. Use this site to help:

http://www.autosportracetech.com/RX-...aryExplanation

 

Thanks for the website, lot's of good info.
Um.. I didn't mean past tence getting about 10 psi or 12 can't remember, but it all sounds and goes good as soon as the second turbo kicks in

 

I pretty much have the same problem. But mine is because my primary was slightly damaged when a not-so-honest tuner blew my engine. Just saving up for a GT35R now. Good luck.