LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

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Old 09-07-2021, 11:38 AM
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Need help

I have a question I just installed headers new plugs and wires the OPTi spark was fine in my 93 Camaro LT one question I知 having is I took the old spark plugs out and they were gapped at 60 the new Accel copper header plugs are gap at .35 I also installed a PCM chip from PCM of North Carolina and deleted the egr car idles fine it痴 a little rough but when I go to put it in gear it stalls and also pops out the exhaust as of right now it is open headers could my spark plug gap be way too low for the 10 to 5 compression ratio that I知 running I do not have any kind of aftermarket ignition set up any help would be appreciated

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Old 09-07-2021, 12:24 PM
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Re: Need help

Are your O2 sensors in the header collectors? With the headers open, the air backwash can screw up the O2 sensor readings. Sensors may also be running too cold, particularly at idle.

The 93's with the original single-wire, unheated O2 sensors can also have problems with headers. That can be resolved by installing heated sensors, if you haven't already done that. Shoebox has a guide:

http://shbox.com/1/heatedsensor2.jpg

What mods do you have besides the headers and chip? Stock plug gap (0.050") should be fine, with platinum plugs. With conventional plugs maybe drop down to 0.045" to allow for the fast electrode wear compared to platinum (or iridium). No reason to run 0.035"
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Old 09-07-2021, 12:36 PM
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Re: Need help

Just headers cold air intake that runs behind the bumper deleted the air pump I put on 8.5 jegs plug wires and copper Accel plugs they are gap at .35 I deleted the egr and the o2 sensors are in the collector痴 I do have a full 3inch exhaust with x pipe and dumps before the axle that I知 having put on
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Old 09-07-2021, 03:07 PM
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Re: Need help

Until you complete the exhaust, it's going to be a problem with it running rich at idle and low engine load. Even then, particularly if you are running long tube headers, the heated O2 sensor conversion will need to be done.

If you feel there are additional items causing the rough idle/stalling at this time, might be a good idea to download a copy (free) of Scan9495, ECM scanning/dataloggig software, and purchase a cable to connect to a laptop. Generally a good way to find a problem like you are having. It will likely show data to confirm the current problem with the O2 sensors.

https://www.camaroz28.com/forums/com...95-lt1-874306/

The author of Scan9495 is a member here and can help with any install or operating issues. I can review the data log.
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Old 09-10-2021, 08:37 AM
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Re: Need help

OK I have another question I did buy a kit that is for the heated O2 sensor as well as new O2 sensors when I go to install them do I have to run them parallel or can I run each power wire separately to a 12 V source with that being said what would be a good source to run it to the ignition or can I run a 12 V on and off switch
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Old 09-10-2021, 11:11 AM
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Re: Need help

Heated sensors have 4 wires. You need to supply switched 12-volt power and a ground to the heater wires in each sensor. The 12-volt power can be taken from a single source, and should include a 10-amp inline fuse. That wire splits to run in parallel to each sensor. From that point, each sensor is wired INDEPENDENTLY. Or you can run independent 12-volt wires.

The switched 12-volt source (hot in RUN) can be picked up from several sources. Have you deleted the AIR pump (fuse 7 U/H), or the A/C (fuse 3 in I/P, and fuse 12 U/H)? If so, those are supplied by "hot in RUN" circuits and can be used.

Ground should be connected to the engine.

The sensing element wire only needs to be connected to the ECM wire that is already there. There will be one O2 sensor wire that is not connected to anything. Shoebox's diagram (link in post #2). shows the typical pinouts on the sensors.

Your "kit" may offer suggestions.

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Old 09-10-2021, 03:43 PM
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Re: Need help

The o2 sensors and wires are a 3 wire that has a ground a power And the individual plug for the one wire That plugs into the existing 02 wire to the ECM so do I have to run them parallel or can I run each power wire with its own individual 10 AM in line fuse to the fuse that was for the air pump



Last edited by Ramrod93; 09-10-2021 at 03:50 PM.
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Old 09-10-2021, 06:44 PM
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Re: Need help

I can’t state it any clearer than I did in the first three paragraphs of post #6, and as shown in Shoebox’s diagram. He clearly labels the 12-volt, ground and ECM signal wires, and clearly shows a fourth wire is not required.

What you pictured is a harness connector, not a sensor. The three wire exactly match what I described in the first paragraph of post #6.
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Old 09-10-2021, 06:51 PM
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Re: Need help

OK I get that I知 not good at electrical stuff but I do know how to work on cars I do know how to read I did read the paragraphs but I知 making sure that I was going to hook it up correctly seeing that I do everything myself there痴 no need to be rude about it I was just simply asking a question thanks anyway
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