2014 Evo X Gsr
Having a rpm problem when at WOT. 1,2 and third gear are fine but when I hit 4th and 5th I can see rpm for from 3500 to 4500 then back to 3500 and pulls from there.
Ive changed all my relays to updated version, cleaned throttle body, checked spark plugs which are still in good shape, and checked all bossy lines and vac lines to make sure they’re on the snug. Only thing I can think of is probably the issue is fuel filter or the injectors. Just changed the oil and it smells like fuel but I know that’s normal.

 

FWIW none of that stuff will fix your problem. You need to check the tach signal and/or grounds. It sounds like an intermittent power issue. If it were the crank angle sensor, then I assume the car would have a CEL or run crappy. So, on the bright side, you can skip that and start working from there.
This is all based on you saying you are "...I can see rpm for from 3500 to 4500 then back to 3500 and pulls from there".
Are you just seeing the tach move or is the car running poorly/cutting power/etc? If running poorly, the easiest way would be to borrow a tacktrix cable and data log what the car is doing. Otherwise, you can pretty much only keep buying parts until the source is found.
Are you smelling clutch?
More info would help, otherwise we're just kinda shooting in the dark, here.

 

Thanks for the reply. That’s the same thing my father in-law said it might be the crank angle sensor or throttle position sensor. I guess imma just buy a wideband and tactrix cable.

 

We still don't know if it's just the tach moving or the RPMs are actually dropping.

 

Are you sure its not the clutch slipping? This is how it starts.

 

classic symptoms of the clutch slipping.

 

If you give it gas and your rpms go up and then come back down and then when they come back down the car pulls , it's your clutch. I just had this problem. Every gear I would gas it rpms would go frkm 2000 to 5000+ hang there a second and the car wouldnt go any faster untill the rpms came back down to about 2500 and then it took off like i was holding the clutch in. How many miles? I just had a comp stage 2 clutch put in and it coated me 1800 . And it's back to normal.


Edit: you may have smelled the clutch from before. If you ever smelled the clutch you'll know it. It is a nasty burnt smell like chemical and rubber and whatever else you can think of. It's very potent and sour.

 

Could be clutch. If OP would answer:

then someone could make a half-way educated guess.

 

Tach signal comes from ECU. ECU knows RPM from the crank angle sensor. If the CAS is wonky, the car doesn't run.

If it was grounds or something else sill you would t have an issue with JUST the tach. Every ground point in these cars has multiple grounds.

OP has a slipping clutch. It's that simple.

 

It's impossible to have failure between the ECU and cluster? Or the cluster itself be damaged? Like we all said, could (probably) be the clutch but OP didn't mention smelling it, mention testing it, or anything else, so who knows.

I'm just tossing out options until he says he found the problem.

 

He is describing 100000% a slipping clutch.

Add Throttle
RPM's spike
RPM's drop
Car goes
And it's currently only occurring in 4th. I'm sure it will do it in 5th too. And as the clutch gets worse, 3rd, then 2nd, and then all gears until the clutch is so bad the car doesn't move

We have these threads like, often...

Based on how OP threw a bunch of unrelated parts at the car, he may not realize what he is smelling. Or he's doing this at like 60, so he doesn't get a chance to smell it.

 

True, true. I also assume clutch, but was really wanting OP to give more info or at least report back.

I also assume he's busy getting the clutch replaced.