The other day I took the rx7 out for a drive and it seems to have gotten slower, significantly slower. Even my roommate noticed. The car used to roast the tires all the way through third gear now it won't even spin in first. Car gets into boost normal and fuel pressure is fine but the car is not revving as fast, almost as if something is holding it back. Is it possible something in the drive train can be causing a load on the engine? Any advice or things to check would be appreciated

Dean

 

It could be sooooooooooo many things and without knowing how modded or stock you are will make it difficult to get very many useful suggestions.

First guess though is a big boost leak.

 

running on trailings?

 

When you claim the boost is fine I am assuming you have a boost gauge and hence you were able to compare the before response vs the after correct?

Given the car is boosting correctly things that come to mind are:

- ECU in limp mode
- clogged cat
- clutch going out

 

Yeah I have a boost gauge. Boost leak was first thing I though but gauge is showing 16psi which is what I run at. Then I thought clutch was going but wouldn't that cause the engine to rev fast? Car is single turbo, straight exhaust so no cats, act 6 puck copper clutch. I thought about running only on trailing plugs, how would I test that?

 

I have turbo 2 differential, my cousin who previously owned the car said diff clutches could be going. Does that sound like it would cause this type of issue? The car feels like it went from 500hp to 300hp

 

Boost is fine, no cats, and not really positive on the clutch given the T2 scenario. But you can use a clamp meter to test if there is current going to your plugs


You can probably rent one from autozone for like 10 bucks or something


If people don't know here I would ask the FC forum about that one.

 

Is it free revving fine?
If it is jack up the and front rear put it neutral and give the back end and front end a spin of wheels by hand. You may have seizing of calipers and/or bearings.

P.S Use stands.....

 

It may be the clutch after all. Sparking was scene under car along with major clutch slippage the other night. I believe the clutch is worn down to the rivets which was causing the sparks. I just replaced the transmission too... should of just replaced the clutch then. Time to put the car back on jackstands...

 

That would explain it. Didn't you smell the odor?

 

No which is why I did not think the clutch was the issue. The clutch definitely needs to be replaced though, so I guess I will see if it solves the issues I was explaining before.

 

What about the tach? if the clutch is slipping then RPM and speed won't track together.

Not saying you shouldn't replace a worn clutch, but a solid diagnosis of clutch slipping would be helpful.