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ls1 way too rich

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Old Aug 19, 2012 | 04:33 PM
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Default ls1 way too rich

finally got my ls1 mustang on the road. seems to idle alright but whenever i give it gas it seems to flood and will almost die if i give it full throttle. smells of raw fuel. its currently running open headers until tomorrow and the o2s arent plugged in, is this the only reason for this symptom?
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Old Aug 19, 2012 | 04:54 PM
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Most likely..you have a Tuner?
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Old Aug 19, 2012 | 05:20 PM
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No I don't have a tuner so I'll need to get it tuned at some point. Just hoping that some back pressure and o2s will keep it from stumbling and flooding
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Old Aug 19, 2012 | 05:32 PM
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the o2s arent plugged in, is this the only reason for this symptom?
Yes, when you don't have o2 sensors the computer is in open loop mode, which is hella rich (it's used for cold startups to get the engine warmed quicker).

That with the fact that you have open headers is going to make for a stinky stinky car.
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Old Aug 19, 2012 | 05:34 PM
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02's make a huge difference on how the car runs and idles.. without them you might as well have a 1050 dominator on the thing lol
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Old Aug 19, 2012 | 05:35 PM
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Ok! That's what I wanted to hear because hopefully tomorrow I'll have that problem ironed out once I have the rest of my exhaust on and o2s
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Old Aug 20, 2012 | 09:13 AM
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remember its still only half GM
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Old Aug 20, 2012 | 09:27 AM
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During my conversion I ran into the rich issue for a few reasons:

1. O2 sensors- tuner will turn off the rear O2

2. Water temp sensor - I tapped off the computer to feed my Autometer gage...big no no. It was reading -40 degrees on a 90 degree day. You must use a seperate sensor in the passenger head.

3. MAF - needs to be plugged in and properly plummed.

4. Vacuum leaks - make sure all the extra ports are plugged.

5. Factory tune was really rich on the dyno.

The good news is my stock 2003 LS1 made 350 rwhp once tuned.
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Old Aug 20, 2012 | 02:18 PM
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I appreciate the responses im working on her today and hopefully will have this worked out
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Old Aug 20, 2012 | 09:04 PM
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Ok guys still running rich. It wants to die because it's flooding but when I unplug the maf it will idle decently. But still when I give it gas it'll flood. What's the next step?
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Old Aug 20, 2012 | 09:21 PM
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Unplug your water temp sensor and see if it is any better.

Also try holding your hand over the MAF with fingers slightly spread. My idle picked up with a little restriction.

The real problem with mine was it was not seeing the TPS because I had converted from DBW to DBC. Once we put the tune in from a 2002 TA it ran very well.
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Old Aug 20, 2012 | 09:23 PM
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I Actually just replaced the water temp sensor because I didn't have one originally but it didn't seem to make much difference. I can smell unburied fuel
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Old Aug 20, 2012 | 10:05 PM
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Get it tuned.
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Old Aug 21, 2012 | 05:36 AM
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Needs a tune I'm sure... what mods does it have?

Do you have larger than stock injectors? If so, there is your problem - don't run it until you get a base tune in it or you risk washing it out. At the very least, you will foul the plugs.

The coolant temp sensor has to be hooked up - don't unhook it as directed above - that will cause it to run way rich too... IAT sensor needs to be hooked up as well...
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Old Aug 21, 2012 | 08:57 AM
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It wants to die because it's flooding but when I unplug the maf it will idle decently.
That just shows that the MAF is not tuned correctly and it's dumping all this extra fuel. Once the MAF is taken out of the equation the car runs fine like you say, so the culprit is clearly the MAF.

Get it tuned.
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Old Aug 21, 2012 | 09:23 AM
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Are we talking a mail order tune? And does it mean the MAF is bad or just not tuned correctly. Sorry I'm really in the dark on the tuning side of things
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Old Aug 21, 2012 | 09:38 AM
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Would the mail order tune allow me to at least get it on the road if I drive it conservatively. Only mods are a zo6 cam and springs done by the previous owner of the actual engine. All sensors are hooked up
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Old Aug 21, 2012 | 10:14 AM
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From: on the dyno tuning in MD
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Yes, a mail order tune would get you a base tune. Sounds like some parts not matched to the PCM are the culprit... unplugging the MAF is only part of it from what you said above. The tune in the PCM has to be accurate for the injectors, MAF, etc - when doing swaps/conversions, if various parts are put together that don't match the tune you will have this kind of problem...

A tuner will need to know exactly what is in the car as far as injectors, MAF, heads/cam, fuel system (including regulator) and probably a few other details...

Your other option would be to trailer it to a tuner... or get tuning software and tune it yourself...
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Old Aug 21, 2012 | 11:36 AM
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I've heard a lot about getting a tune from Frost. Not really sure what I'm looking or asking for?
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Old Aug 21, 2012 | 02:48 PM
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I'm not a fan of mail order tunes..I do my own stuff with my own software.

There is a difference between "close enough to run" and spot on to the build IMO. Then again that depends on your tuning techniques.
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