Mrbowtie26

iTrader: (3)

Just installed my 402 i put together, rescaled the injectors and raised the idle slightly with ls1 edit. Got the motor started and it has oil pressure... Thats the good news the bad is that it is running ungodly rich and barely idleing. Problem is that my tach is staying at 0 . I used the racetronix i believe plug and play cam wires for the ls2 block so idk if that could be the problem ? i heard that sometimes wires are on backwards ? is this true ? Any idea's would be appreciated. p.s. car is a 2000 T/A, 402 ls2 block, afr 225 heads, fast 90/90 and 42 lb injectors (lucas)

DrkPhx

iTrader: (15)

Sounds like the cam sensor wires, but that shouldn't happen with a PnP harness. The crank sensor should stay the same. You may need to switch the two outside wires of the cam sensor. You also need to reduce the lower VE table to help with the rich idle. Does the car backfire or pop by any chance?

Mrbowtie26

iTrader: (3)

I did lower the main VE table from 0-1200 by 5% but yeah when its trying to start i heard it pop a little. Also yeah i meant the cam wire in the front of the block on the ls2 my bad

Mrbowtie26

iTrader: (3)

anyone else, ideas ? ttt....

Beast96Z

iTrader: (21)

That harness has had some issues with 2 of the wires being backwards. You should be able to search to find which ones. I believe "orangepeel" had the same issue with his.

Orange Peel

iTrader: (20)

Check this thread, I had the same issues and it has some good info in it....

https://ls1tech.com/forums/generation-iii-internal-engine/495874-damn-ls2-cam-position-sensor.html

Mrbowtie26

iTrader: (3)

It was a good read with some helpfull info thanks. The question I have is that I got the block from SLP and it came with the front cover with sensor already installed. I would assume that the sensor they give me would be the correct one for the cam sprocket they gave with the kit. For now I'll try swapping the outside wires on the plug I got from racetronix and see if that works as I can't get to the back of the plug behind the intake as my hands are too big I am aware some people have had some issues with SLP motors in the past but I'm just looking for a fix at this time. Any other ideas would be appreciated.
Thanks
Ron H.

Beast96Z

iTrader: (21)

It is highly possible that SLP put the wrong cam sproket on or sent you the wrong one. SLP has horrible quality control. If swapping the wires dosen't work, that'll probablly be the problem.

Mrbowtie26

iTrader: (3)

Ok i tried swapping the outside wires and still same problem. As a side note I bought the motor about a year and a half ago. I believe I need the 2005 sprocket and not the 2006 isnt that correct ? I checked and found the bag for the chain they sent me and the part number was 12586482 and was dated 4/22/05 so i would think that i got the correct sprocket. Did they have the wrong sprocket back then in april of 2005 ? any other help would be appreciated.
Thanks
Ron H.

Mrbowtie26

iTrader: (3)

Any info on how to properly diagnose if I have a problem with my cam sensor, wiring, or possibly crank sensor bad ? idk just looking for some other ideas . I'm going to go out and double check the wiring to everything and all grounds.
Thanks
Ron H.

1BADAIR

iTrader: (1)

are the grounds on the heads tight

Mrbowtie26

iTrader: (3)

Yes, also i just went out and checked and signal voltage at plug with ignition on is 12v at pin C which according to the service manual is correct. Also when I check the C terminal and put the black wire of the voltmeter on either of the other 2 pins for a ground i am reading 12v. Is this correct ? according to the schematic terminal B is Low reference and terminal A should be Cam pos. sensor signal input but Im not sure if they both could be used as neg to get a 12v reading at C ?
or if one of them is shorted ? not sure at this point. Any help would be appreciated.
Thanks
Ron H.

Mrbowtie26

iTrader: (3)

Also I talked to SLP today and they said they havent had any issues with anyone getting the wrong cam sprocket with their 402 motors and had no idea what I was talking about .....they said to check all my grounds and the wires going to the cam sensor and the crank sensor.

DrkPhx

iTrader: (15)

Are you getting any codes? Did you actually check the camshaft sprocket? There is very obvious difference between a LS1 (holes) and LS2 (no holes, raised bar) sprocket.

Mrbowtie26

iTrader: (3)

I dont have a scanner and cant really or dont want to really keep it started dumping sooo much fuel in. I know it was a newer raised design but cant remember if it was the single raised section on it or more. it def. wasnt like the original one though. I would hate to rip everything off the front of the motor to check and find out thats not the problem if I could have found it without doing that. Like I said I got the block in mid 2005 so I'm not sure if It would have the 2005 or 2006 ls2 sprocket. I would assume it had the correct 2005 unless they came out with the 2006 in mid 2005 .

DrkPhx

iTrader: (15)

You should be fine with either raised bar version. Mine was also dumping alot fuel when I first started. So I had to rescale the injectors, switched back to a stock heat range plug, reduced the lower VE by 5-10% and also reduced the cranking VE by 2%. That helped alot.

Katech_Jason

iTrader: (19)

Do you have a build sheet and part number for the sprocket?

Follow the wires up from the cam sensor and make sure A and C get reversed and the connector is plugged in properly.

Mrbowtie26

iTrader: (3)

https://ls1tech.com/forums/showthread.php?t=495874

I thought according to a post on this thread you needed the 2005 sprocket, as it has only 1 raised spot ? I would think the one with more raised spots would throw the sensor off ? And I did lower my Main VE from 0-1200 by 5% and it didnt do anything. so you are aware car barely can keep running even with me giving it a little throttle, and it is running richer than i have ever seen in a car by FAR the entire area stinks within about 20 seconds of raw fuel. I read in manual that if it was a problem with the crank sensor car wouldnt start at all, I think it is something to do with the cam sensor as my tach doesnt work, but not sure how to properly diagnose it at this point.
Thanks
Ron H.

Mrbowtie26

iTrader: (3)

Wires are on correct, I do not have a build sheet as SLP just shipped me the shortblock with the timing cover, valley cover and the timing chain and sprocket. I can call them tomorrow and see if they have a part number on the sprocket . They said they havent had anyone that purchased thier 402 shortblock have a problem with the sprocket being the wrong one when I talked to them.
This is just frustrating at this point lol
Any help is appreciated.
Thanks
Ron H.

p.s. is there any way I can probe the wires while cranking the engine to see if sensor is reading the sprocket ? I know there is a way of checking it but I'm not sure how.

DrkPhx

iTrader: (15)

If you had a scan tool, you could verify rpms when cranking.

GM switched to the different cam sensor and sprocket sometime during the 2005 production year.
Try this:

1) Turn the ign ON (engine off), and using a digital multi meter (DMM) check the voltage on the ignition feed (red wire) and using a battery or chassis ground. Should be 12v or close.

2) Do the same as above except connect the DMM ground to the CMP ground wire (pink/black). Should be 12v or close.

You need to use the above to check the PCM side connector in two separate locations. First, remove the PnP harness and check the factory harness, then reinstall it and check the PnP connector (PCM side). Results should be the same. You can also try a new cam sensor.

Sounds like you have the GM manuals. If so, refer to troubleshooting & diagnosis for DTC's P0341, P0342 and P0343.