Won't rev past 4500?

[Chewy954]

Not sure why I cant rev past 4500 rpm's. There are no boost leaks at all. What do you guys recommend me doing next?

The car is untuned with 550cc injectors, think a tune or 450's will fix this?

 

[xMINORxTHREATx]

Are you just trying to rev while in neutral?
Is it automatic or 5spd?

 

[Chewy954]

5 speed

during neutral is revs perfectly, just in gear it doesn't...

 

[Phantom DSM]

We need a better description than not revving past 4500 . Does it feel like you hit a wall once you get there, like power just stopped?
Does the the engine sound like its all popping and sputtering, and wont go past 4500 ?

 

[Chewy954]

Sorry.

It's not like a wall, its like a rev limiter... just sits there and doesn't pass it, not like hitting a wall.

 

[Phantom DSM]

Rev limiter, hmmmm thats weird. I was expecting the usual fuel cut problems or misfiring on the higher rpm's. I woul really go and check for boost leaks again man. If you have a boost gauge , how much boost do you go up to and what does i feel like?
Do you get full boost?

 

[BrokenTsi]

are you running some kind of keydiver chip or dsm link with a clutch wire?

 

[Chewy954]

My boost is set to 8 psi which is boosts to and you feel it until it hits that one point I explained :\

No dsmlink or anything. EFI systems, yes.

 

[MY1GDSM]

When was the last time you looked inside your ECU?

Nevermind...
Missed that you had a aftermarket ECU

 

[juanpac0]

I hope you're not running NGK Platinums or any platinum plug.

 

[BrokenTsi]

I looked at your mod list. Take off that MSD ignition and run the stock ignition. Ive been running 10's for a long time on stock ignition. I would try that first.

 

[Chewy954]

I hope you're not running NGK Platinums or any platinum plug.

the guy had platinum :/ Bad?

 

[silentscreamer]

One thing that was not mentioned and i had this problem is a rocker arm popping off of the lifter, since its only the cam and the tension of the lifter holding it in place. this had happend to my car before i got it and it wouldnt rev past 5000 easily. i pulled the valve cover and found the rocker arm from an intake valve cylinder #1 lying in the head.
its an easy check and doesnt take more than 10 minutes to pull it of and take a quick look.

 

[Phantom DSM]

the guy had platinum :/ Bad?

I'm assuming you got this car from someone recently ??

Platinum creates too hot of a spark for the 4g63. You need copper plugs NGK BPR6ES silver box. Gap them between .028 - .032. Follow valuable advice from members here. I do support removing the Msd to try solving this problem. If you are sure you have no boost leaks or anything, then you either have an ignition problem or ecu problem. Try the original coils and check you spark plug wires. Good luck

 

[MY1GDSM]

One thing that was not mentioned and i had this problem is a rocker arm popping off of the lifter, since its only the cam and the tension of the lifter holding it in place. this had happend to my car before i got it and it wouldnt rev past 5000 easily. i pulled the valve cover and found the rocker arm from an intake valve cylinder #1 lying in the head.
its an easy check and doesnt take more than 10 minutes to pull it of and take a quick look.

WTF
Only time I've ever seen a louse rocker arm was when a head had bent valves

 

[Phantom DSM]

and the plot thickens.

 

[Chewy954]

What spark plugs should I get and would platinum cause this?

 

[Phantom DSM]

I'm assuming you got this car from someone recently ??

Platinum creates too hot of a spark for the 4g63. You need copper plugs NGK BPR6ES silver box. Gap them between .028 - .032. Follow valuable advice from members here. I do support removing the Msd to try solving this problem. If you are sure you have no boost leaks or anything, then you either have an ignition problem or ecu problem. Try the original coils and check you spark plug wires. Good luck

i'am quoting myself
If you scroll up a bit you'll notice i mentioned a solution for your bad plugs. Start from there NGK BPR6ES .028-.032.

 

[Chewy954]

how do i check if my ecu is bad? :/

 

[MY1GDSM]

how do i check if my ecu is bad? :/

Am I missing something something again?
it's not a mitsu ecu right?

 

[Chewy954]

it should be.. why wouldnt it be? o_o

 

[MY1GDSM]

from your mods list
"EFI systems inc ecu"
???

IF its not that stand alone then
open the case and look inside and see if the Caps are leakin'
look for white chalky lookin stuff in it or anything out of the norm.
I've seen quite a few ecu's the were fried and had problems revin' past 4-5k

 

[rush2252]

Does it get to 4500 then just stop pulling? Or is it sluggish while it gets there?

 

[silentscreamer]

I know what you mean usually the valves are bent when the rocker arm pops off. its usually due to jumped timing which was the case with my car. but after compression tests and leakdown tests i know i dont have any bent valves. i faught with this problem for about 4 months untill i got bored one day and decided to put in some 3g lifters and problem was solved. but to make it more clear as to what my car was doing, it was revving fine in neutral but in any gear it would start to lug a big at 4500 or so and 5000 and up it woulld be running rough even with a constant 10 lbs boost. also the plug for cylinder #1 was a little bit leaner than the rest.
maybe if you can post a log so that everyone can see what the ecu is doing to cause this it might help out.

 

[Chewy954]

it just stops pulling. Tomorrow I will be doing a spark plug change and I'll let you know how it goes.