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Old 05-25-2013, 05:29 PM   #1
smoky02
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Issues

Alright my swap is done but I'm having a few problems that I was hoping someone on here could help me out with. When she idles she runs good. But when I'm driving she has a few times that she skips or misses. Also when I start it I have to feather the gas like its still carbed. Also when I pull up to a light and leave it in drive it lurches, but if I put it back in neutral it idles smooth. If anyone's knows what could be causing these problems pleases let me know.

Brandon
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Old 05-25-2013, 05:31 PM   #2
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Re: Issues

Mods please move to the LS swap section
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Old 05-26-2013, 01:41 AM   #3
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Re: Issues

Best bet would be to get a scan tool and see what's going on.
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Old 05-26-2013, 02:13 AM   #4
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Re: Issues

See if its throwing a code, and which one. If its actually misfiring and stumbling, you've got things like the plugs, wires and coils to look at. Things like a dirty or stuck injector can cause bucking and stumbling as well.

When the engines' in neutral, there isn't any load on it so those problems might not be as obvious over the regular shakes and noises of a cammed ls.

Also things like a vacuum leak, issue with the tune, improperly hooked up brake switch causing issues with the trans etc.
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Old 05-26-2013, 11:44 AM   #5
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Re: Issues

The only code I'm throwing is p0101. And it's not consistent that makes me think it's not in the ignition system.
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Old 05-26-2013, 10:42 PM   #6
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Re: Issues

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Originally Posted by smoky02 View Post
The only code I'm throwing is p0101. And it's not consistent that makes me think it's not in the ignition system.
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That's a MAF trouble code, assuming your ECM is still MAF based it could be throwing off your tune in all kinds of ways. Where did you put the MAF in relation to the throttle body? Also, is it new or old (did it come with a salvaged motor?)
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Old 05-26-2013, 02:03 PM   #7
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Re: Issues

Check your fuel pressure and spark plugs
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Old 05-26-2013, 04:48 PM   #8
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Re: Issues

What should my fuel pressure be at?
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Old 05-26-2013, 06:17 PM   #9
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Re: Issues

In the 50'S psi range.
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Old 05-27-2013, 07:30 PM   #10
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Re: Issues

The MAF is new from the parts store. And it's run at the end of my cold air intake.
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Old 05-27-2013, 08:35 PM   #11
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Re: Issues

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Originally Posted by smoky02 View Post
The MAF is new from the parts store. And it's run at the end of my cold air intake.
Well all that sounds fine. I would look and make sure the wires aren't cut or rubbed by accident, maybe chafed on something? Also it's possible you over oiled your air filter element and some of it made its way onto the MAF. I doubt that would cause your symptoms, but it would throw the code. A bad MAF wire somewhere could be causing your issues however.
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Old 05-28-2013, 11:52 AM   #12
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Re: Issues

I had that code as well. I just cleared it and it hasn't came back. I've ran it a few times without the maf connected testing things. Clear the code and keep checking the basics.
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