to make a long story short..tonight a friend of mine came to me with a problem with his car. he has a 93 RX-7..and complained about the car not making boost sometimes...and at other times it WOULD make boost. When i drove it..the symptoms were there...every once in a while when i punched it..it would make boost...but at other times the car felt as if it were making power on the motor alone. Also his idle is kind of rough. Now about the boost problem..could it perhaps be his actuator?? and the idle..perhaps the plugs? any help would be greatly appreciated.

This is actually my car but I didnt feel like writing it over but I do need help. It almost seems as if the actuator is stuck open because I just lose boost at 4500 RPM when the second turbo comes online but i'm not sure. Has anyone encountered a similar problem? any help would be great

 

Well to be honest your account of the symptoms are not saying much. How much boost, when it's low, have you looked under the hood yet for blown couplings, popped off vacuum hoses etc. The more specific you are the easy the problem is to assess.

Paul

 

Ok well I havent exactly gone under the car to look for any popped off hoses but as far as I can see there are none that are popped off but i'm only hitting about 8 pounds in 2nd gear with my friends boost gauge then in 3rd gear most of the time I dont get any boost at all. Although the 2nd turbo has never come online on my car my boost will just drop in every gear after 4500 no boost after that. I'll hopefully check it tomorrow and post again whether its any of the vaccum hoses as i'm going to take off the throttle body and check under there.

 

Sounds like I have a brother in arms! Actually, my problem is with my puirple computer, b/c car boosted fine w/o computer installed. Haven't figured out my problem beyond that though. Do you have any mods? Have you done your vacuum lines yet? If not, that should be first priority. PM me if you figure it out.
Good luck.

 

If the boost comes on sometimes and it doesn't come on other times, it's the soleniods. Find out what gears this happens in and it will help you pin point what soleniods you need. I had the exact same problem, they said it was a "sticky soleniod". Sometimes it opens, sometimes it doesn't. It's all the heat that gets to them that makes this problem occur. I hope I helped you out.

 

At this point I wouldn't discount a clogged pre cat or cat. As the RPM increases so does the exhaust flow. Thta's why at higher RPM (4500) the flow will get restriced enough to prevent the turbos from spoolin gproperly.

Paul

 

Very good point!! I didn't think at 112k on my car the cat is probably solid. Mabey when I installed the pmc it exasturbated the problem b/c of higher boost levels. Guess I gotta gut the cat this week....

 

https://www.rx7club.com/forum/showth...threadid=98645
Look at this thread. It might be helpful, as well as this site. http://home.istar.ca/~dvandit/rx7stuff.shtml
When your boost immediately drops off at 4,500 it usually isn't a clogged cat. Also, getting low boost in different gears can be because you shift once the turbos are in nonsequential mode.

 

The boost almost never comes on at 1st or 3rd gear and when I do boost it always hits about 8 psi in 3rd. Plus the boost hits 0 psi after 4500 all the time.