again, what you're saying is ambiguous...I honestly don't know what you're talking about, you need to word it differently...

 

I guess maybe you have to be a racer to understand the problem we have. I've had others read this and understand the problem just not the sollution. This is part of the reason I sold the lancer to my cousin these things are way to finicky.

 

Does the new motor have a different looking crankshaft pulley? that's the only difference I can think of that would make the engine get to the rev limiter sooner. Or a lighter rotating assembly

 

ok, you're right, everything you're saying makes perfect sense, and I don't understand because I've never raced my car

have fun being a "racer", and good luck with your problem..

 

Wow at least crans wished u good luck

 

Is it a completely stock eclipse engine that you picked up? Only thing I could think of hitting the rev limiter (assuming its still in the same place) is that you either have a lightweight crank pulley or the previous owner of the engine got rid of the balance shafts.

Other possibility could be that the camshaft has a different profile than in the RA engine as bakuro said previously. Blocks should still be the same along w/ the crankshafts so it has to be in the top end somewhere. Sensors I wouldn't imagine would be any different within the 4g69 engines.

Do you even know the cause of why the previous engine blew? Could lead to the solution why this engine is acting differently.

 

The old engine started missing coming out of the turn on a quarter mile track should have been about 3500 rpm blew at the end of the straight no more than 5500 rpm. All the pistons had come in contact with valves but #2 piston was missing and the cylinder busted. Timing belt looked good and was in time so we really didn't find a cause. The new engine is out of an 08 eclipse with 52,000 miles completely stock except the lancer intake and aftermarket header which were both on the old engine. Where does the computer get the signal for the tack?

 

lol nope you haven't crans

This thread is a fail!

 

What was the peak rpms previously when it would not hit the limiter ?
At how many rpms is the rev limiter engaging now ?

 

I concur.

 

My interpretation is that he believes the ECU is reading the RPM of the new engine incorrectly high, and therefore cutting the engine out prematurely. Because the ECU is seeing an inflated RPM number the tach is indicating an inflated number as well. Cutting the RPM too soon would be reducing his top speed on the track.

How to fix this, I have no idea.

 

^^^^ Swap the sensors at the crank that detect its rotation ???

 

i've looked through the wiring diagrams, and i can't find where the "engine speed detection" circuit gets its input...

 

Did you ever fiddle with your valve trains?

 

My bet is now on variations in the base tune between the RA and the Eclipse. Something must be slightly different between the two that your RA ECU isnt getting right... Cams, Compression, Something... I mean, there where ECU and Cam differences between the few years they made the RA. And I know that the Eclipse was designed to use an exhaust with two cats instead of just one like the RA. Maybe try finding an 08 Eclipse ECU and see if that changes things. If not it has to be something with the engine.

Actually. Hackish does tunes on the 4g Eclipses doesnt he? I wonder if he knows of any differences between the OEM ECUs on the 4g and the RA? Hell maybe just getting Hack's reflash could fix the issue and we know it could raise your redline....