Fuel pressure help!
01-27-2007, 01:45 AM
#11
I ♥ Acer
Join Date: Apr 2006
Location:
Posts: 5,116
RE: Fuel pressure help!
I use a SFMU with 42's....with 42's the fmu isn't needed with 8 psi...36's would be better.....I run 2 lines 1 is with the 190 I have and another is hooked in to the sfmu..the sfmu is more tuneable.... your stock 'puter can't run the 42's so to speak....hard starts and low rpm issues...I don't believe the 42's would cause your problem....question..how old is the timing chain? have you tried closing the gap to .32 on the plugs?....have you test engine for ALL vacuum leaks?
ORIGINAL: 93must
It is about 8lb of boost, and the plugs are autolites gaped at .35 I think? Whatever Vortech told me to set them at.I would get rid of the fmu because the chip would control all of the fuel. The fmu does not really adjust the fuel properly from idle to WOT. it is just operated by vacum and depending on which diaphram you have in there it will either run rich or lean at WOT.I would dyno it and then burn the chip to fix the lean and rich problems at dif points in the throttle position.
It is about 8lb of boost, and the plugs are autolites gaped at .35 I think? Whatever Vortech told me to set them at.I would get rid of the fmu because the chip would control all of the fuel. The fmu does not really adjust the fuel properly from idle to WOT. it is just operated by vacum and depending on which diaphram you have in there it will either run rich or lean at WOT.I would dyno it and then burn the chip to fix the lean and rich problems at dif points in the throttle position.
ORIGINAL: 2 kwik
ok.first how much boost? why are you getting rid on the FMU? if you do then bigger injectors are a must!..you might what to look at a pms,tweecer,mega squirt for what you'll pay for a tune and if you upgrade you have to pay him again..something to think about
ORIGINAL: 93must
I just installed a fuel pressure gauge. I set it at 39 psi with the vacume line off and it drops to about 35 when I hook it back up, which I think is normal. the question is my fuel pressure goes up to about 40 when I role into it! Is that normal for it to go up? I cant go WOT yet cause I have to get rid of the FMU and get the chip tuned for it, which I will be doing in a couple of months. I just want to get most of the bugs worked out so I dont have to pay to much for the adjustment to the tuner! It has a pre det problem under a load and I have the timing at 8 degrees and my boost retard set at 3 degrees! So I am trying to figure that out also! Does to much fuel cause a pre det problem also?
I just installed a fuel pressure gauge. I set it at 39 psi with the vacume line off and it drops to about 35 when I hook it back up, which I think is normal. the question is my fuel pressure goes up to about 40 when I role into it! Is that normal for it to go up? I cant go WOT yet cause I have to get rid of the FMU and get the chip tuned for it, which I will be doing in a couple of months. I just want to get most of the bugs worked out so I dont have to pay to much for the adjustment to the tuner! It has a pre det problem under a load and I have the timing at 8 degrees and my boost retard set at 3 degrees! So I am trying to figure that out also! Does to much fuel cause a pre det problem also?
01-27-2007, 01:53 AM
#12
3rd Gear Member
Thread Starter
Join Date: Jun 2006
Location: Oregon
Posts: 598
RE: Fuel pressure help!
The car has no other issues besides the pre det! It starts, runs, and idles fine in the cold or when its warm. I have not tried to close the gap but am thinking about trying that tommorow. The timing chain has never been changed, and it has 80k on it. And I am sure it has no vacuum leaks. I know the injectors are big for what I have but will be going with afr heads and a cam eventually and didnt want to have to buy them twice.
01-28-2007, 01:38 AM
#13
The Rogue Mod
Join Date: Feb 2006
Location: Maryland Sucka's!!
Posts: 21,918
RE: Fuel pressure help!
ORIGINAL: 93must
The car has no other issues besides the pre det! It starts, runs, and idles fine in the cold or when its warm. I have not tried to close the gap but am thinking about trying that tommorow. The timing chain has never been changed, and it has 80k on it. And I am sure it has no vacuum leaks. I know the injectors are big for what I have but will be going with afr heads and a cam eventually and didnt want to have to buy them twice.
The car has no other issues besides the pre det! It starts, runs, and idles fine in the cold or when its warm. I have not tried to close the gap but am thinking about trying that tommorow. The timing chain has never been changed, and it has 80k on it. And I am sure it has no vacuum leaks. I know the injectors are big for what I have but will be going with afr heads and a cam eventually and didnt want to have to buy them twice.
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