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Faster on half throttle compared to full.


stagefumer11

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this is a intresting and well im dumbfounded on it.

 

I own a R30 skyline w ith a L20et in it,. now when it push it hard on Full throttle it will........well. It actaully pulls harder and better on half throttle.

 

could over fuleing or Timing Be the problem ?. I also have a second problem with my Ecu wich is a diffrent matter but stuffs around with the coil and Fuel pump.

 

50/50% of the time my car will start fine in any weather. but say after 5 mintes of driving it will die. the fuel pump stops. yada yada. and will not turn on when turning the key. leaving it for 5 minites and it will : /. Ive replaced the fuel pump, so i know its not that.

 

It can also sit there when you have the key on the "on" possition and CLikc on and off really qucikly. this is the relay for my fuel pump. Ive swaped them arounnd. a nd it can still do it. this inturn makes my fuel pressure regualtor open and close also. Hence my fuel pump turning on and off.

 

The only way to really fix this was to unplug the ECU (fouund this out today) and plug it back in, and woolaaa the car starts again.

 

please can anyone lend on insite into this since im a newbie at all this. ive got the car along way from what it was. and it runs alot better. Talk about a big learning Curve for me! :-D

 

 

Cheers. Nick

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good to see this is totaly pointless in posting here :(

 

At full pedal your pump is probably not providing enough pressure to feed the engine at those rpms, there you get the loss of power. When you are at half pedal, your pump can keep up with the little demand for fuel, hence the feeling that you have more power at half pedal.

 

Maybe change your pump, fuel filter, and have your injectors cleaned. Also, check to see your AFM is opening all the way when you go full pedal.

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Guest livewire23

is the car stumbling and bogging at full throttle, or is it just slow? Also, is it backfiring through the intake?

 

As far as the fuel pump is concerned, run some 10 gauge wire and be sure when its on. I have a switch wired in my dash with a light that indicates when the pump is on.

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the car deosnt really bog, it just looses power and its like a surging feeling. :/ i reaplced the fuel pump with a spare i had , i dont know of the condition of this one. probably worth getting a new one.

 

fuel filer is new, and all the pump filters have also been cleaned .

 

if my AFM isnt opening the full way can you adjust them? . ive had one open before of this make.

 

"injectors". humm can you clean them yourself ?. or does it have to be pro done ?

 

 

cheers, thanks for the replys guys

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If you have already changed the puel pump, and the filter, regulator, o2 sensor etc are all working fine, it may be time to check for a clogged exhaust. This used to be a more common problem with early catalytic converters, but I haven't ever seen it on a newer car. However, a clogged cat or muffler will cause the behavior noted, runs fine at mid-throttle, bogs down and is slow at full throttle. The back pressure builds up and the engine can't breath. Look for a bent exhaust tube, or if the converter is pretty rusty, it could have deteriorated enough to clog.

 

Just a thought.

Jeff E.

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Check the vacuum line that runs from the manifold to the fuel pressure regulator, replacement of vacuum hoses every 5 or so years will cut down on a lot of bugs. Plugs wires and distributor cap, and plugs are your next cheapest option. Check the wiring harness, and the rubber intake hoses for cracks.

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