I'm in the process of installing a J-spec turbo engine in my '90 convertible and need some advice/information about the air pump. I'm having trouble getting my left-drive engine harness routed because there's no room behind the pump. The pump on the US N/A engine that came out of the car is a different design that leaves plenty of room for the harness. I don't have a US TII pump to compare but I believe it is similar.

Given that I want to retain a functioning air pump, what's the better solution? Find and install a US-spec pump (and brackets, and hoses and air control valve), or is it reasonable to use the J-spec pump and run the harness over the top of the whole mess? I'm inclined to do the the latter, even though it doesn't leave enough length to route the harness along its original path to the firewall, but maybe there are other issues that make it advisable to use the US parts.

-evan

 

well you will probably have to convert to the US spec pump, simply because the Jspec pump is smaller and may not have sufficent flow to make the cat work correctly and still pass CA emissions

 

Damn. I hadn't even thought about that. The US pump is bigger, but it has a larger diameter pully, so it turns slower. I don't know if that would even things out or not.

The concern I have is just that the pumps are different. There must be a reason, and that reason may have to do with the way the pump is used under the control of the different ECUs. I know installing the US pump is the Right Thing, but I was hoping someone would tell me it's OK to use the J-spec pump because I'm lazy and impatient.