I own an 88' RX-7 GTU. I've recently noticed a slight sputtering noise, not the normal back pressure pops after revving the engine, but a more consistant putputputputput. I've also noticed a loss of power, and when it is hot out from idle to about 4000 rpm there is a "woooshing" noise, i belive eminating from the fan, fanbelt. IF anyone has any ideas, please help.

 

Hmm, could be lots of things...

Anti-afterburn valve in the ACV blew its diapragm?

Or, something else on the ACV not quite right...

Could be cats, maybe, especially if you're hitting a "wall" at higher rpms...

Could just be a vac leak...

 

What is the ACV? I was also thinking the 5th and 6th ports arent opening, because at 3800 there is no noticable power increase

 

Well, if you have a nice size vac leak somewhere, you're not going to attain the manifold pressures necessary for the boost sensor to tell the ECU to kick on the secondaries...that's one theory, anyway....

The ACV is the air control valve, should be on the right side of the engine, below the intake, but above the exhaust manifold. Got a couple of solenoids on it.

Do you hit a "wall" at all, or is it just basically very sluggish past 3800?

Still could be a lot of things, do you have a Haynes manual or the Factory Service Manual to troubleshoot with?

 

Yeah i think i might have a vacuum leak, how do i check? No its not really sluggish past 3800, the car runs pretty well, especially at higher rpms, but when the ports open arent you supposed to experience a noticable boost? Its pretty linear acceleration up to redline. but i did notice a loss of power since i bought it, and the added sputtering noise that didnt used to there. I recently obtained a factory manual (one didnt come with my car, the kid i bought it from didnt have one) so i'll look though that and see if i can troubleshoot anything. thnx for your help wayne.

 

when my 5th and 6ths were stuck. i was able to get a semi smooth acceleration up till about 7's/ and wayne is right , if you have a vaccum leak the ports wont open. you also might wanna check and see if they are stuck like mine were.. huge difference after freeing them up . . how many miles on the car?? stock exhaust?? rule out the simple things first . does the car idle steady ???