Where is my top end?

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I have a 97 ITR motor in a EG. My car feels good until i push it hard, VTEC engages at 6.2k but Around 7.2k my power is just gone, almost like a huge flat spot. I did a compression test and a Air leakage test and the motor is healthy. Im not buring oil or even coming close to overheating, and no CELs. Im using the JDM P73 and I also using the JDM harness(looks getto but works) and i have my KS wired up. What could cause this. I had my pop check on ALLDATA for loss of power and this what came up:
1 Fuel Pressure- (using the stock 92 si fuel pump)
2 Throttle body
3 Throttle Cable (it opens all the way)
4 Manifld Absolute Pressure (MAP) sensor
5 Throttle Position (TP) sensor
6 Air Cleaner (AEM V2 CAI)
7 Intake Air Bypass (IAB) contorl system and intake air pipe (ruled this out only on GSR)
8 Three Way Catalytic Converter (TWC) (ruled out also)

If it was the TP or MAP wouldnt i throw a CEL? Can it be my KS retarding my timing (im running 91 octane). I wanted to test my MAP to day, but my repair book only said how to check the conection, witch turned out to be OK, how do I check the MAP its self? What can be some other problems im stumped? :worthy:


Senior Member
Could you be more specific when you say loss of power. Like loss of power as if VTEC is disengauaging (which would feel like a sudden slowing effect) or as if the engine has no more to give (it has produced the maxium amount of power it can muster.)


correct me if i'm wrong, but i'm pretty sure 6.2k is well above where the p73 kicks vtec in. seems rather high. i would assume it would be 5500-ish.

i don't think its any particular sensor. like you asid, it would throw a code if it were bad.

how's your oil pressure?
do you have another ecu to try? a chipped p28 or p30 or something...

stock pump should supply enough fuel.

you could be leaning out up top or losing timing.

IMO, i'd go to a dyno, and do 2 or 3 pulls.. print the graphs, come home and show us them with the wideband plot on it.


Originally posted by pissedoffsol@Jun 10 2005, 08:51 AM

IMO, i'd go to a dyno, and do 2 or 3 pulls.. print the graphs, come home and show us them with the wideband plot on it.
[post=510662]Quoted post[/post]​

Im going to try to make it to a dyno and see what comes out. just need to save up some more cash. thanks


Just wondering on the chipped ecu. I got burned on ebay by "jdmdohcpower" or something like that. It is a p28 (unshure the sticker is gone) should i try to run that. I ran it a little but it had a bad idle so i put it away, never even botherd to run the car hard with that ecu.

Phearable.net are these guys any good. I saw a ad on this site.

p.s. is there away to open the ecu up and see what type of ecu it is.