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Old 08-28-2013, 07:02 PM   #1
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Car running lean, help!

I had my car on a dyno not too long ago and the air/fuel mixture ran 17.2, they said it should be at 12.8. It's running really lean and they said it can cause problems. How can I fix this? I just bought a sct eliminator chip, just waiting for it to come in.

My mods are:
Cold air intake
Gt-40 aluminum heads
X roller rockers
Under drive pillows
Fms headers
Mac H pipe
Borla exhaust
65mm throttle body
Gt-40 upper intake

How can I run less lean so I can get around 12.8? Thank you!

---------- Post added at 05:02 PM ---------- Previous post was at 05:02 PM ----------

Did have an exhaust leak at the time so it should be not quite as lean, but it would not have changed it that drastically .
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Old 08-28-2013, 07:03 PM   #2
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Quote:
Originally Posted by Evolution View Post
I had my car on a dyno not too long ago and the air/fuel mixture ran 17.2, they said it should be at 12.8. It's running really lean and they said it can cause problems. How can I fix this? I just bought a sct eliminator chip, just waiting for it to come in.

My mods are:
Cold air intake
Gt-40 aluminum heads
X roller rockers
Under drive pillows
Fms headers
Mac H pipe
Borla exhaust
65mm throttle body
Gt-40 upper intake

How can I run less lean so I can get around 12.8? Thank you!
Stock fuel pump and injectors?
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Old 08-28-2013, 08:54 PM   #3
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If you didnt upgrade your fuel system with those mods then you need to look in to doing that.
Upgrade to a new high flow fuel pump and step up the injectors to 24 of 30 and be sure to get a adjustable fuel pressure regulator and you should be all set.

Good Luck!
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Old 08-28-2013, 10:32 PM   #4
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Originally Posted by TheBandit View Post
If you didnt upgrade your fuel system with those mods then you need to look in to doing that.
Upgrade to a new high flow fuel pump and step up the injectors to 24 of 30 and be sure to get a adjustable fuel pressure regulator and you should be all set.

Good Luck!
What kind of fuel pump should I get? How much lbs?

---------- Post added at 08:32 PM ---------- Previous post was at 08:32 PM ----------

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Originally Posted by DustyStang306 View Post

Stock fuel pump and injectors?
And ya It's stock for both.
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Old 08-29-2013, 04:12 AM   #5
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You should get some 24lb injectors and also a maf calibrated for 24lbs
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Old 08-29-2013, 11:30 PM   #6
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You should get some 24lb injectors and also a maf calibrated for 24lbs
Ok, how would I get my maf calibrated to 24lbs? Or would I have to buy a pre-calibrated one?

---------- Post added at 09:30 PM ---------- Previous post was at 09:30 PM ----------

And what would that do?
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Old 08-30-2013, 04:11 AM   #7
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Ok, how would I get my maf calibrated to 24lbs? Or would I have to buy a pre-calibrated one?

---------- Post added at 09:30 PM ---------- Previous post was at 09:30 PM ----------

And what would that do?
you need a set of 24lb injectors.. you have 19lb stock. and then a new maf, pro-M is good. warlboro 255lph fuel pump.
then once you do those 3 things, have it tuned again.
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Old 08-30-2013, 05:28 AM   #8
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You have to buy a new MAF sensor programmed for 24lb injectors and it's recommended to get a larger housing. The stock 55mm housing is said to only be good to roughly 300bhp per PRO-M.

And agreed on the larger fuel pump. You don't want to risk the lean conditions, you could possibly ruin your engine.
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Old 08-30-2013, 05:34 AM   #9
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Getting a MAF sensor calibrated for 24lb injectors will allow your engine to run properly at all engine speeds. There's a good article you can read in 5.0 magazine from 2003 they did with PRO-M that goes through the science behind it if you wanted to learn more. You can google it and should come up.
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Old 08-30-2013, 05:54 AM   #10
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Imo its better to be a little rich than lean... either ways not good. but I run 93-up octane on the street and I bumped my timing just a bit at the track last time out.. hit spark knock over 3500 rpm.. NOT a good thing lol.

also worth noting I found a small vacuum leak at the rail after that pass so that helped add to the lean condition
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Old 08-30-2013, 06:02 AM   #11
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Agreed! I'll take a little rich over lean any day. At least you know it's safer. In my experience there definitely seems to be a fine line with the timing.
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Old 08-30-2013, 06:13 AM   #12
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Agreed! I'll take a little rich over lean any day. At least you know it's safer. In my experience there definitely seems to be a fine line with the timing.
oh yeah there is.. that's why good tuners cost so much... anyone can change stuff in a computer..the good tuners took their time to really learn their trade.

and, OP, with how rich you're running.. I wouldn't even take the car out of the driveway.. you get that one good detonation and there goes a piston or block.. also, it'd be worth investing in a wideband setup to keep an eye at all times. for your mods, 19lb injectors should work, not ideal, but you shouldn't be THAT lean.. stock gt40 motors have 19 lb injectors

---------- Post added at 08:13 AM ---------- Previous post was at 08:13 AM ----------

lean* not rich
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Old 08-30-2013, 12:39 PM   #13
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oh yeah there is.. that's why good tuners cost so much... anyone can change stuff in a computer..the good tuners took their time to really learn their trade.

and, OP, with how rich you're running.. I wouldn't even take the car out of the driveway.. you get that one good detonation and there goes a piston or block.. also, it'd be worth investing in a wideband setup to keep an eye at all times. for your mods, 19lb injectors should work, not ideal, but you shouldn't be THAT lean.. stock gt40 motors have 19 lb injectors

---------- Post added at 08:13 AM ---------- Previous post was at 08:13 AM ----------

lean* not rich
Hey OP, a good test to check how lean you are without sensors is clean your plugs (or put new ones in) and do a REALLY hard wot 1000ft run. then pull a couple plugs and get a pic of them. one plug from each bank should work. then, clean them again and unplug your maf and do another run.. check them again. unplugging your maf will force your injectors into 100% duty cycle. you will most likely run rich like that. do that if you can and post the results.

when I got my 95 gt, the maf was fubared and unplugged and it ran rich enough to fuel a 3rd world country off the exhaust haha I got a maf at the wreckers and it ran lean as hell.. so I adjusted the piping angles and gave it a thorough cleaning. 2-3 times of that and the a/f is good.
might be worth a shot if you haven't tried that. oddly enough the angle of an aftermarket in-fender cai can affect the maf's accuracy. the first elbow can cause the air charge to go past the test tube rather than thru it.
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Old 09-02-2013, 11:49 PM   #14
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So where would I buy a precalibrated maf for 24lb injectors? I fixed a major exhaust leak so it shouldn't be at 17.2 anymore, should be lower, plus a I have a sct eliminator chip coming in by friday Hopefully that will fix some, I will do injectors and then fuel pump more than likely.
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Old 09-03-2013, 12:53 AM   #15
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oh yeah there is.. that's why good tuners cost so much... anyone can change stuff in a computer..the good tuners took their time to really learn their trade.

and, OP, with how rich you're running.. I wouldn't even take the car out of the driveway.. you get that one good detonation and there goes a piston or block.. also, it'd be worth investing in a wideband setup to keep an eye at all times. for your mods, 19lb injectors should work, not ideal, but you shouldn't be THAT lean.. stock gt40 motors have 19 lb injectors

---------- Post added at 08:13 AM ---------- Previous post was at 08:13 AM ----------

lean* not rich
GT-40's run 24lb. Injectors

---------- Post added at 06:53 AM ---------- Previous post was at 06:51 AM ----------

And how are you running a GT40 upper without a GT40 lower? They don't match up GT40 ports are staggered and regular GT intake ports are inline
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Old 09-03-2013, 03:44 AM   #16
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I'm not running a gt40 anything to my knowledge. I've been trying to figure out where everything on this motor came from. Made some progress yesterday and found out my intakes from a fox..

And what year gt40 had 24lb? No gt40 explorer I've looked at has had 24lbs. Unless, you're talking about cobras? In which case I have no idea. Never worked on a 5.0 cobra.

---------- Post added at 05:44 AM ---------- Previous post was at 05:40 AM ----------

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So where would I buy a precalibrated maf for 24lb injectors? I fixed a major exhaust leak so it shouldn't be at 17.2 anymore, should be lower, plus a I have a sct eliminator chip coming in by friday Hopefully that will fix some, I will do injectors and then fuel pump more than likely.
Pro-m is a good company for a maf. But unless you have 24lb injectors themselves, buying a maf is just going to add to your problems.
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Old 09-03-2013, 10:17 AM   #17
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Originally Posted by BloodRedStang View Post
I'm not running a gt40 anything to my knowledge. I've been trying to figure out where everything on this motor came from. Made some progress yesterday and found out my intakes from a fox..

And what year gt40 had 24lb? No gt40 explorer I've looked at has had 24lbs. Unless, you're talking about cobras? In which case I have no idea. Never worked on a 5.0 cobra.

---------- Post added at 05:44 AM ---------- Previous post was at 05:40 AM ----------



Pro-m is a good company for a maf. But unless you have 24lb injectors themselves, buying a maf is just going to add to your problems.
I bet you aren't running GT40 anything considering you have a V6, the OP stated that he has GT40 aluminum heads and GT40 upper intake
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Old 09-03-2013, 12:15 PM   #18
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I bet you aren't running GT40 anything considering you have a V6, the OP stated that he has GT40 aluminum heads and GT40 upper intake
I have a 95 GT 5.0.

And I relized what you said was directed at the OP after I replied. I got confused.
I was wondering that as well. Aren't the gt40 and e7 style lower intakes different? Like the gt40s runners are staggered and stock is in a straight line?
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Old 09-03-2013, 01:27 PM   #19
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Yup, GT40's are staggered. Sorry for the mix up, you need to change your vehicle, it says you have a '95 V6
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Old 09-03-2013, 04:57 PM   #20
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I must have gt-40 lower intake aswel then. So I just have to upgrade my maf and it's pre calibrated or what?
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Old 09-03-2013, 05:08 PM   #21
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It is as long as you order it as such. Usually anywhere you order from it should give you an option of what injectors you want/need it calibrated for.
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Old 09-03-2013, 05:43 PM   #22
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How about a pic of your intake?
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Old 09-03-2013, 06:46 PM   #23
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Yup, GT40's are staggered. Sorry for the mix up, you need to change your vehicle, it says you have a '95 V6
Yeah, I can't figure out how to change that or my profile pic on mobile.. I never log on on a computer.. lol
That v6 I had got totalled and I bought my gt last month lol
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