First Datamaster Scan
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
First Datamaster Scan
I went for a drive tonight and got my first Datamaster readings. I'm slowly learning about all this and have been looking through the readings. I'm wondering if anyone can take a look at it and tell me if there is anything to change because my car is running very rich. Thanks!
http://www.mts.net/~jimmers/Test.uni
http://www.mts.net/~jimmers/Test.uni
Last edited by jimmers; Jul 10, 2007 at 07:28 PM.
Melting Slicks
Joined: Nov 2000
Posts: 2,469
Likes: 6
From: Winchester Ontario
I'll throw my one cent in here (don't know enough for two cents worth).
108 is really rich. I suggest getting an adjustable fuel pressure regulator and lowering your fuel pressure a bit.
The others who normally respond would probably like to know if it's a modified engine and the size of your injectors and such. If you just bought 24 or 30 pound injectors without altering your chip, this would result in being too rich as well.
108 is really rich. I suggest getting an adjustable fuel pressure regulator and lowering your fuel pressure a bit.
The others who normally respond would probably like to know if it's a modified engine and the size of your injectors and such. If you just bought 24 or 30 pound injectors without altering your chip, this would result in being too rich as well.
Racer
Joined: Jan 2004
Posts: 458
Likes: 1
From: NY
I went for a drive tonight and got my first Datamaster readings. I'm slowly learning about all this and have been looking through the readings. I'm wondering if anyone can take a look at it and tell me if there is anything to change because my car is running very rich. Thanks!
http://www.mts.net/~jimmers/Test.uni
http://www.mts.net/~jimmers/Test.uni
Burning Brakes
Joined: Sep 1999
Posts: 786
Likes: 31
Cruise-In II Veteran
If you are running stock injectors I would be suspicious of one or more of them are bad. The stock 1990 injectors are notorious for going bad.
Try testing each of them with an ohm meter and see what the resistance across the coils is. Low or no resistance indicates failure of the injector.
Are you throwing any codes?
Try testing each of them with an ohm meter and see what the resistance across the coils is. Low or no resistance indicates failure of the injector.
Are you throwing any codes?
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Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
I'll throw my one cent in here (don't know enough for two cents worth).
108 is really rich. I suggest getting an adjustable fuel pressure regulator and lowering your fuel pressure a bit.
The others who normally respond would probably like to know if it's a modified engine and the size of your injectors and such. If you just bought 24 or 30 pound injectors without altering your chip, this would result in being too rich as well.
108 is really rich. I suggest getting an adjustable fuel pressure regulator and lowering your fuel pressure a bit.
The others who normally respond would probably like to know if it's a modified engine and the size of your injectors and such. If you just bought 24 or 30 pound injectors without altering your chip, this would result in being too rich as well.
.The engine has been rebuilt, Edelbrock intake, Edelbrock runners, 24#injectors, ported heads and plenum, Hooker 2151 Headers, Comp Cam.
Here are the specs of the cam
Duration @ .050"
212* Intake/218* Exhaust
Gross Valve Lift
.488" Intake/.495" Exhaust (with 1.5 ratio rocker arms).
Would it be ok to lower the fuel pressure lower then 40lbs?
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
My old injectors were leaking quite a bit so I dont have reliable stock injectors.
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
Intermediate
Joined: Mar 2007
Posts: 40
Likes: 0
From: Crestline Ohio
Do you burn your own chips?
Have you read about VEmaster or VEphd over at thirdgen.org?
if not read it kiks azz, great program for SD ecu's
I would leave the pressure at like 44-47 and tune the computer, while changing FP, might fix some area's of the programing it will hurt others and will limit the amount of power the injectors can support.
( I'm sure you know this but, it is good to have if you don't)
New Flow = Old Flow x √ (new pressure / old pressure)
22.6 = 24 x (sqrt)(40/45) (your old injectors work the same with your modes it is probably lean at wot)
FWHP = ([INJECTOR SIZE (LB/HR) X DUTY CYCLE] / BSFC) X (# OF INJECTORS)
For NA cars use a BSFC of 0.50, for blown cars, use 0.55. Assume a duty cycle of 0.85.
with that all said a good guide line would be.....
24(lb/hr) / .07 (rough) = 342hp (flywheel hp support)
21(lb/hr) / .07 (rough) = 300hp (rough ans. but simple)
19(lb/hr) / .o7 (rough) = 271hp
with your modes/rebuild you should be around the 340ish mark which should need 24lb @ atleast 43 psi.... so my point is let Vemaster fix the cruising fuel and part thottle, and keep all your power too....
Have you read about VEmaster or VEphd over at thirdgen.org?
if not read it kiks azz, great program for SD ecu's
I would leave the pressure at like 44-47 and tune the computer, while changing FP, might fix some area's of the programing it will hurt others and will limit the amount of power the injectors can support.
( I'm sure you know this but, it is good to have if you don't)
New Flow = Old Flow x √ (new pressure / old pressure)
22.6 = 24 x (sqrt)(40/45) (your old injectors work the same with your modes it is probably lean at wot)
FWHP = ([INJECTOR SIZE (LB/HR) X DUTY CYCLE] / BSFC) X (# OF INJECTORS)
For NA cars use a BSFC of 0.50, for blown cars, use 0.55. Assume a duty cycle of 0.85.
with that all said a good guide line would be.....
24(lb/hr) / .07 (rough) = 342hp (flywheel hp support)
21(lb/hr) / .07 (rough) = 300hp (rough ans. but simple)
19(lb/hr) / .o7 (rough) = 271hp
with your modes/rebuild you should be around the 340ish mark which should need 24lb @ atleast 43 psi.... so my point is let Vemaster fix the cruising fuel and part thottle, and keep all your power too....
Thread Starter
Safety Car
Joined: Mar 2005
Posts: 4,723
Likes: 11
From: Winnipeg Manitoba, Canada
I've tried using VEmaster and have had a bit of success. It will correct most of the rich cells, but after using it a few times I have alot of lean cells now. What exactly is VEphd, I've never heard of it? Does it do the same type of thing as VEmaster?
