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Old Aug 15, 2009 | 12:34 PM
  #21  
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I moved from the US to Montreal and my car immediately got crappier mileage. Doesn't really make sense although the gas here is crappy 91 compared to sunoco 93 i used to use back home. I live in a city environment and i get around 40miles when the fuel gauge is on 3/4s. So around 11-12mpg. Sucks, but i can't do anything. I even touched 9mpg right before i stored the car last year, super cold, combined with a short drive. I think i went WOT once in the past year in a half. To many stop signs, lights, etc. My car is fully tuned, filters changed, etc. Im sure if i drove the car normal, i would get single digit gas mileage.
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Old Aug 15, 2009 | 12:53 PM
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So you have no idea what's going on either?
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Old Aug 15, 2009 | 02:51 PM
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Originally Posted by Aggie_Ls1
Bump. Still hard to start and still bad gas mileage. o2's are brand new.

Could the starting problem be a bad fuel pressure regulator? I have a fuel pressure gauge to hook up to it, but im not sure what the pressure should look like during the test. It spikes at 60 when i turn the key on then falls to 55 immediately, then proceeds to steadily fall off to zero (takes about a minute to get to zero).
Sounds like a fuel leak if its dropping off to zero. See any puddles or drips. Could be the pump that has the leak I suppose and then you won't see any drips.

Also, you could have a leaky fuel injector thats killing that pressure. That would also explain the bad gas mileage.


.
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Old Aug 15, 2009 | 03:19 PM
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Hard starts can be fuel pressure regulator. That's what happened to my car.

As far as gas mileage, really don't know. Is it running super rich or something?
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Old Aug 15, 2009 | 05:09 PM
  #25  
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Is there any way to check the FP reg? How much would one cost? Im assuming a stock replacement from an autoparts store is the way to go?

My car's been dyno tuned with a wideband so as far as i know the tune is fine, unless something else is throwing it off?
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Old Aug 15, 2009 | 05:45 PM
  #26  
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Originally Posted by LS6427
Sounds like a fuel leak if its dropping off to zero. See any puddles or drips. Could be the pump that has the leak I suppose and then you won't see any drips.

Also, you could have a leaky fuel injector thats killing that pressure. That would also explain the bad gas mileage.


.
Okay cool. I did think about a leaky injector or the pump leaking in the tank but how would i figure out if one of these was the problem?

I don't see or smell any gas around the injectors anywhere.
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Old Aug 15, 2009 | 05:56 PM
  #27  
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Originally Posted by Aggie_Ls1
Okay cool. I did think about a leaky injector or the pump leaking in the tank but how would i figure out if one of these was the problem?

I don't see or smell any gas around the injectors anywhere.
The injector would leak into the cylinder that it serves. Could be from a hole in the atomizer filter from wear. Once it reached zero pressure it would stop leaking and it would evaporate.

Pain in the *** way, take all the spark plugs out, turn the key on and let the fuel pump bring the pressure up and see if fuel comes out or the smell of fuel. Maybe you'll be able to hear it.

Or alot easier, take all the injectors off and check them out visually.

Leaking at the pump.....I don't know how to verify that. But if it was leaking at the pump or a line in the tank it wouldn't effect your gas mileage because its not wated gas. A leaky injector will kill your gas mileage. I know someone with a Dodge Hemi truck that had a leaky injector, couldn't really tell, the engine ran perfectly fine, but a half tank of gas would be gone rather quickly and it started all of a sudden. It was a single leaky injector.

.
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Old Aug 15, 2009 | 06:21 PM
  #28  
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Originally Posted by LS6427
The injector would leak into the cylinder that it serves. Could be from a hole in the atomizer filter from wear. Once it reached zero pressure it would stop leaking and it would evaporate.

Pain in the *** way, take all the spark plugs out, turn the key on and let the fuel pump bring the pressure up and see if fuel comes out or the smell of fuel. Maybe you'll be able to hear it.

Or alot easier, take all the injectors off and check them out visually.

Leaking at the pump.....I don't know how to verify that. But if it was leaking at the pump or a line in the tank it wouldn't effect your gas mileage because its not wated gas. A leaky injector will kill your gas mileage. I know someone with a Dodge Hemi truck that had a leaky injector, couldn't really tell, the engine ran perfectly fine, but a half tank of gas would be gone rather quickly and it started all of a sudden. It was a single leaky injector.

.
Alright man thanks ill check that out asap. Im gonna pull the injectors first i think.
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Old Aug 16, 2009 | 11:10 AM
  #29  
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Originally Posted by Aggie_Ls1
So you have no idea what's going on either?
I wish i knew. I mean granted, it did get worse, after the header install, and taking off EGR/AIR, but hwy was still good. When the car just had a cutout/lid/ported TB it got 30mpg on the hwy consistently. After headers, i got around 28mpg, and now im probably down to mid 20s. Not sure what the deal is since i don't smell unburnt gas at all. I have given up. Someimes i think its the city city driving mixed with the crappy gas here. When i go back to the US. The gas mileage picks up.
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Old Aug 18, 2009 | 07:31 PM
  #30  
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Originally Posted by LS6427
The injector would leak into the cylinder that it serves. Could be from a hole in the atomizer filter from wear. Once it reached zero pressure it would stop leaking and it would evaporate.

Pain in the *** way, take all the spark plugs out, turn the key on and let the fuel pump bring the pressure up and see if fuel comes out or the smell of fuel. Maybe you'll be able to hear it.

Or alot easier, take all the injectors off and check them out visually.

Leaking at the pump.....I don't know how to verify that. But if it was leaking at the pump or a line in the tank it wouldn't effect your gas mileage because its not wated gas. A leaky injector will kill your gas mileage. I know someone with a Dodge Hemi truck that had a leaky injector, couldn't really tell, the engine ran perfectly fine, but a half tank of gas would be gone rather quickly and it started all of a sudden. It was a single leaky injector.

.
When I pull the injectors to inspect them what do I look for? Do i pull one at a time, leave it hooked up and then turn the key and check for leaking after the system is pressurized?
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Old Aug 19, 2009 | 06:23 AM
  #31  
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just pop the rail up with all the injectors on it and prime the key(do not crank), since the PCM is not pulsing the injectors they should all be closed and there fore hopefully you will find one that is leaking.
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Old Aug 19, 2009 | 09:05 AM
  #32  
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Okay thanks ill give it a shot.
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