i cant find the problem!!!!

[BNaylor]

There is nothing wrong with your fuel pressure so why waste the money or continue spinning your wheels. For your engine fuel pressure should be in a range of 50-60 psi per the GM Factory Service Manual.

Further, you should not be running E85 gasoline especially with mods. Premium unleaded 91 octane or better. I don't recall any Grand Prix year or model being Flexfuel capable.

Final note is if you decide to change the fuel pump assembly unlike the '97-'03 GP models you have to drop the gas tank. There is no longer an access cover in the trunk area that can be removed.

[tomshaze]

Originally Posted by BNaylor

There is nothing wrong with your fuel pressure so why waste the money or continue spinning your wheels. For your engine fuel pressure should be in a range of 50-60 psi per the GM Factory Service Manual.

Further, you should not be running E85 gasoline especially with mods. Premium unleaded 91 octane or better. I don't recall any Grand Prix year or model being Flexfuel capable.

Final note is if you decide to change the fuel pump assembly unlike the '97-'03 GP models you have to drop the gas tank. There is no longer an access cover in the trunk area that can be removed.

on the new gtps i know theres no panel but i have a friend with a shop
and min fuel pressure is 60 psi and max is 62 i have read everywhere that fuel pressure is suppose to rise the more you press

on the older gtp the fuel pressure was lower look

soorry this is the only proof i could find

http://www.autozone.com/autozone/par...=87023_5356_0_

see min psi is 60 at 20 % throttle mine drops to 59 from 61 and continues to drop and why do i go lean at 130 mph???

[BNaylor]

Per the GM FSM fuel pressure is not to exceed 60 psi or you have a problem but we'll consider you have mods. Note the specs on that aftermarket fuel pump at your link is maximum 60 psi.

Going lean most likely because your fuel injectors are too big. 60#?

Just to be sure could you list all your engine mods? Do you have an intercooler, hot cam?

[tomshaze]

Originally Posted by BNaylor

Per the GM FSM fuel pressure is not to exceed 60 psi or you have a problem but we'll consider you have mods. Note the specs on that aftermarket fuel pump at your link is maximum 60 psi.

Going lean most likely because your fuel injectors are too big. 60#?

Just to be sure could you list all your engine mods? Do you have an intercooler, hot cam?

fuel sucking mods:
1.95 roller rockers
105 springs
full 3 inch exhaust y pipe no res no cat
wizaired intake
60 pound injectors
motor mounts
pacesetter heADERS
ngk tr6
e85 which uses 42 more fuel than gasoline
a heavy foot

when i first switched to e85 car ran great for 2 weeks
people sat about 600 miles into e85 you should change you fuel filter cuz its gunna clog up due to the e85 cleaning up your tank
i have my fuel filter in my tank so its never been changed
i have gone lean before i ran full e85 with out a tune yes im stupid
and it feels like that at higher sppeeds
i cant get past one 30 cuz it jumps like its not getting enough feel

[tomshaze]

and all that with the stock fuel pump and also original fuel filter with 108 thousand miles

[tomshaze]

Originally Posted by BNaylor

Per the GM FSM fuel pressure is not to exceed 60 psi or you have a problem but we'll consider you have mods. Note the specs on that aftermarket fuel pump at your link is maximum 60 psi.

Going lean most likely because your fuel injectors are too big. 60#?

Just to be sure could you list all your engine mods? Do you have an intercooler, hot cam?

strait from wiki
Fuel filter

If any of these conversion techniques are used, especially in older vehicles in which there may be rust or other residue present in the fuel tank, it may be necessary additionally to replace the fuel filter within 400 to 600 miles, as ethanol has a tendency to release any trapped rust or gasoline fuel gum or residue, which can cause the fuel filter to become blocked. Once replaced, life expectancy of the new fuel filter should be normal, barring an exceptionally dirty gas tank or fuel system.
Running E85 in a vehicle can actually improve fuel efficiency if the fuel delivery system was especially clogged up. This improvement remains if the vehicle is returned to operation on gasoline only.

[BNaylor]

Just so we all understand so you decided to do an E85 engine build. Correct? I realize on E85 builds you need more fuel supply and delivery but why did you decide to do this versus sticking with the conventional way we mod?

Who or what shop did your power tuning?

[tomshaze]

what is the conventianal way we mod?

[tomshaze]

Originally Posted by BNaylor

Just so we all understand so you decided to do an E85 engine build. Correct? I realize on E85 builds you need more fuel supply and delivery but why did you decide to do this versus sticking with the conventional way we mod?

Who or what shop did your power tuning?

i got it done hurr in the valley dyno tune by de leon

just went to cut my hair hur and had the pressure guage set up 61 psi idle 10 percent throttle 59.5 psi
400 rpm 56psi
redline 53 psi

[BNaylor]

Originally Posted by tomshaze

what is the conventianal way we mod?

Tuning to use unleaded fuel to include unleaded race gas and not fuel composition consisting of 85% alcohol. Personally I would not waste any time, resources or money doing an E85 build and running E85 fuel.

Have you run a check of knock retard (KR)? Also, have your tuner double check the MAF settings. E85 builds require custom MAF/VAF tables which means doing alot of experimenting.

What are you short and long term fuel trims reading?

[tomshaze]

Originally Posted by BNaylor

Tuning to use unleaded fuel to include unleaded race gas and not fuel composition consisting of 85% alcohol. Personally I would not waste any time, resources or money doing an E85 build and running E85 fuel.

Have you run a check of knock retard (KR)? Also, have your tuner double check the MAF settings. E85 builds require custom MAF/VAF tables which means doing alot of experimenting.

What are you short and long term fuel trims reading?

idk i read them but didnt know how to read them at the time ill read them again in a bit

i just did a fuel volume test i got exactly 1 pint in 30 seconds with the engine idleing i think kinda low for the fuel demands i need???

[BNaylor]

Originally Posted by tomshaze

idk i read them but didnt know how to read them at the time ill read them again in a bit

For long term or short term fuel trims using a scan tool capable of logging the data the ideal figure to achieve is 0 % but that will probably never happen. Ideal fuel trim = zero. Greater than zero indicates the PCM is adding fuel to compensate for the lean condition. If fuel trim is less than zero the PCM is reducing the amount of fuel to compensate for a rich condition.

The fuel trims are considered abnormal when you see the following on the scan tool on a L32 SIII 3800 or L67 SII 3800 engine.

LT fuel trim is greater than (+) (-) 17%. ST fuel trim greater than (+) (-) 2%.

If the fuel trims are really off a P0171 or P0172 DTC should set.

Originally Posted by tomshaze

i just did a fuel volume test i got exactly 1 pint in 30 seconds with the engine idleing i think kinda low for the fuel demands i need???

I'm not an expert on E85 builds but IMO your fuel injectors are too large given the mods you have and for your whp. The figures I've seen are 30% for more fuel supply increase. The stock fuel injectors are rated at 33#. So 42.5# injectors are more in line with your particular E85 build and mods versus using 60#.

Also you might consider investing in your own powertuner like an HP Tuners kit if you plan on continuing to run E85.

[tomshaze]

Originally Posted by BNaylor

For long term or short term fuel trims using a scan tool capable of logging the data the ideal figure to achieve is 0 % but that will probably never happen. Ideal fuel trim = zero. Greater than zero indicates the PCM is adding fuel to compensate for the lean condition. If fuel trim is less than zero the PCM is reducing the amount of fuel to compensate for a rich condition.

The fuel trims are considered abnormal when you see the following on the scan tool on a L32 SIII 3800 or L67 SII 3800 engine.

LT fuel trim is greater than (+) (-) 17%. ST fuel trim greater than (+) (-) 2%.

If the fuel trims are really off a P0171 or P0172 DTC should set.



I'm not an expert on E85 builds but IMO your fuel injectors are too large given the mods you have and for your whp. The figures I've seen are 30% for more fuel supply increase. The stock fuel injectors are rated at 33#. So 42.5# injectors are more in line with your particular E85 build and mods versus using 60#.

Also you might consider investing in your own powertuner like an HP Tuners kit if you plan on continuing to run E85.

every one thinks its 30 percent more its actually 42 percent

well think about it think way if i was maxing out my 33 # with gasoline

i easliy max out e85 on 42 thats why i decided to get the big dogs i was gunna get 80 #

idk my cars maf lb per min or what every is 2.12 around there and calclload at idle is 40 percent

i have check numnerous cars that say .62 or .84 but not 2 at idle

oh i think about getting a power tuner every day i dont wanna pay no more

[tblake]

Originally Posted by tomshaze

every one thinks its 30 percent more its actually 42 percent

well think about it think way if i was maxing out my 33 # with gasoline

i easliy max out e85 on 42 thats why i decided to get the big dogs i was gunna get 80 #

idk my cars maf lb per min or what every is 2.12 around there and calclload at idle is 40 percent

i have check numnerous cars that say .62 or .84 but not 2 at idle

oh i think about getting a power tuner every day i dont wanna pay no more

Ok, now I'm Lost.

[tomshaze]

Originally Posted by tblake

Ok, now I'm Lost.

lol sorry