LT1-LT4 Modifications 1993-97 Gen II Small Block V8

threw a code today P1371 help please!

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Old Sep 7, 2008 | 10:39 PM
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Default threw a code today P1371 help please!

P1371 - IC 4X Reference Circuit Too Few Pulses

is what the guide i found in this section told me the code was. i am no mechanical genius but i can navagate my way through the car well, does anyone know what this means thou? i dont even know where to start. the car has just been intermitently running a slight bit rough, and it flooded 2 times different days. please any advice would be great thanks!
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Old Sep 7, 2008 | 10:47 PM
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Opti code, either the opti is on its way out OR your opti harness just melted through.
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Old Sep 7, 2008 | 10:54 PM
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yea i just googled it too haah and found some stuff about the opti and harness, but my question is will be it real obvious is the harness is bad and exactly where is it located (sorry noob question)

because i just replaced my opti like 6-7k miles ago! and don't want to have to change that **** again!
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Old Sep 7, 2008 | 11:00 PM
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Definitely check that harness out first then, it comes off of the left side (when your looking straight at the engine from the front) of the opti and runs up from there to the left side of the intake manifold, and hooks into the main harness right there (with another clip, midway down the intake manifold on the left).

Either unplug it totally and take it out to inspect, or just expose the wires from the platic protectors and make sure they are all ok (not burnt/rubbed/corroded through). Also check the connectors on either end, you cant imagine how many rusty/corroded opti harness terminals I have seen cause problems.

And I think I asked you this before but... When you replaced the opti before, what kind of opti did you use?
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Old Sep 7, 2008 | 11:01 PM
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It's the wiring harness that plugs into the top of the opti and runs to the top, passenger side of the intake manifold.
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Old Sep 7, 2008 | 11:02 PM
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well i had the shop do it the first time, and im almost postitive its a deltec one. those are the factory gm ones right and supposed to be better? and i also have a new water pump too that was replaced when the opti was too.
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Old Sep 7, 2008 | 11:06 PM
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You should check with them to see what they used, smaller shops dont always use factory parts. AC Delco is what you should have, and always use for stock replacement. If you have a higher revving LT1 or an LT1 making some big numbers, thats when I would be looking into an MSD or Dynaspark setup...

But AC Delco before anything else, because nobody knows what the car needs more than GM.
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Old Sep 7, 2008 | 11:15 PM
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Originally Posted by Fixxer99TA
You should check with them to see what they used, smaller shops dont always use factory parts. AC Delco is what you should have, and always use for stock replacement. If you have a higher revving LT1 or an LT1 making some big numbers, thats when I would be looking into an MSD or Dynaspark setup...

But AC Delco before anything else, because nobody knows what the car needs more than GM.
yea good call man, well this guy that i went too is one of the best guys in phoenix for several services on LT and LS cars so i would be willing to bet he did use the AC Delco, i will check thou still thanks for all the help!

and the car has a Speed Inc Cadillac Cam, 1.6RR's,dual valve springs, new pushrods, lifters, water pump, opti, and a tune running throu exhaust manifolds unfortunately just to the cats and out of my y pipe i chopped the muffler off. i've got the long tubes under my bed, just need the cash to pay for the catback before i can install them.

thanks again fixxer99TA!
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Old Sep 7, 2008 | 11:19 PM
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No problem man, if this guy knows LT1s and LS1s then no doubt hes using AC Delco (I would still check though, you never really know...)

If this truely is a brand new AC Delco opti and its throwing this code....It could be a few things....

1. Oil leak from the opti seal in the timing cover letting oil into the opti.
2. Frayed/corroded wires in the opti harness.
3. Corroded terminals in the opti harness.
4. Just a bad Opti from GM, it happens but obviously this is the last guess.

The first of which most likely being shop error (installing it incorrectly, not replacing the opti seal when doing the opti, ect.... ect....). You have everything covered, and I dont think your brand new water pump is leaking causing this problem (which is the usual opti suicide).
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Old Sep 8, 2008 | 10:39 AM
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hey thanks for all the help man, im gunna go home tonight and start checking it out, im also gunna call the guy today at lunch to see if it is the AC Delco for sure.

i'll let you guys know how it goes tonight after i get home from work and get a chance to check this bad boy out haha. Stupid Opti! haha
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