engine wont rev past 4500 rpm

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Dec 19, 2003 | 04:28 AM

slammin

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engine wont rev past 4500 rpm

i had the stage 4 in my car custom dyno tune and i took it off so i could trade the car in. the only things i left on is the uppipe and the fuel pump in the tank. the car idles fine revs to 4000rpms fine but then feels like it has no advance in the timing. could the fuel pump be dumping to much fuel. how do you change the timing on these cars or is that done by the computer?

Please help me?

Dec 19, 2003 | 08:09 AM

Egan

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From: Peoples Republik of Kalifornia

Car Info: 05 H2 SUT, 45 GPW, 10 Murano, 13 Boss 302

Any CEL's? Sounds almost like limp mode.

That being said, the fuel pump should make no difference. The fuel regulator will control how much pressure gets through and the injectors will control how much flow gets through. Did you put the stock injectors back on or are you running something larger?

If all you have is the pump and an uppipe, the stock ECU should have no problem adjusting. Did you reset the ECU after you pulled everything off?

Dec 19, 2003 | 07:43 PM

slammin

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thanks for the reply. after driving to work today i smelled gas. stopped and the injector on the drivers side was leaking. i dont know if the rubber gromet on the top was sliced or if the one on the bottom fell off in the process of putting it back on. i will tackle the problem tomorrow.. if it is in limp mode how do i reset the computer. the cel light is always on due to the exhaust i have.. although with the uppipe and stock turbo back i wonder if i will get a cat cel now... hope i can fix it i only have until jan. 2 to get an extra thousand off a chevy truck..........

thanks,
Neil

Dec 20, 2003 | 01:02 PM

Egan

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From: Peoples Republik of Kalifornia

Car Info: 05 H2 SUT, 45 GPW, 10 Murano, 13 Boss 302

You need to pull the code. Don't just assume it's the constant CEL from your exhaust. There may be something else going on.

Dec 20, 2003 | 01:33 PM

Kevin M

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From: Reno, NV

Car Info: 1993/2000/2001 GF4 mostly red

If you have the stock exhaust on, you shouldn't be throwing a CEL except for the EGT sensor, which can be taken care of with a resistor. However, you do need to be certain what the CEL(s) are.

Dec 23, 2003 | 05:47 PM

slammin

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I took it to the dealer today and they said it looks like its the tgv sensor on the driver. They said they are not positive but they will be sure in the morning. To me this does not sound right. What do you think.. I thought that was only for cold starts. I have to find out tomorrow what cels they got.

Neil

Dec 25, 2003 | 09:36 AM

Pi7467mp

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From: Colorado

Car Info: 2000 2.5 RS USDM STI block, SOHC heads GT25 Ball bearing turbo, TMIC, TXS BOV, Tial wastgate, etc...

Hey man I had the same problem, but I don't know if this is what is going on in your situation.. I would floor my car and under boost I would get this sputtering exhaust note around 4500 RPM... and I thought it was in limp... but My car was running way too rich.. according to suby sources... if you are running way too rich under boost in High rpms, your primary O2 sensor is overwhelmed and makes you car not able to run past 4500 RPMs unless you go that route under partial throttle.. hope that helps.

Dec 25, 2003 | 11:28 PM

Egan

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From: Peoples Republik of Kalifornia

Car Info: 05 H2 SUT, 45 GPW, 10 Murano, 13 Boss 302

Quote:

Originally posted by Pi7467mp
Hey man I had the same problem, but I don't know if this is what is going on in your situation.. I would floor my car and under boost I would get this sputtering exhaust note around 4500 RPM... and I thought it was in limp... but My car was running way too rich.. according to suby sources... if you are running way too rich under boost in High rpms, your primary O2 sensor is overwhelmed and makes you car not able to run past 4500 RPMs unless you go that route under partial throttle.. hope that helps.

Which is exactly why I asked him if he still had the larger injectors in his car. I know for a fact the ECU will cause the car to buck with the STi injectors. Way too much fuel.