Hi everyone. I am trying to gut my car up and running a after a long 2 years down. I installed a efi connection 24x kit with a custom harness, ls2 coils, and a ls1 pcm on my 89 l98 6-speed vette. Im still running the sbc platform but with the ls running system. With this kit you use a custom 24x reluctance ring and custom billet timing cover that accepts a crank sensor and then you use a 2001 express van dummy distributor as your cam signal. It converts to a coil on plug design and no longer uses a distributor. I had a set of custom fabricated valve covers made that i can mount my coils to. I also installed a comp double roller chain and comp 276hr cam that has 545lift with the 1.6 rockers, re worked 113 aluminum heads with bigger Manley valves and a all comp roller valve train. Also installed a tpis mini ram, twin 58mm tb, and 30lb injectors. The car also has tpis a/c and air delete brackets, tpis headers and y pipe with no cats and a tpis rear section. Now that you know a little about the car here is my problem. I took my car to my tuner and it keeps throwing a p0342 cam position voltage high and p0343 cam position voltage low codes. We have tried many tunes and it will not go away, we have also checked the harness with a dvom from cam sensor to pcm and checked for all the powers and grounds and they all looked good. We have replaced the cam sensor and even swapped in a custom road runner tuning pcm and it still wont go away. when i put this car together i triple checked to make sure that the cam timing was rite so i don't believe it is that. Im starting to wonder if maybe the dummy distributor is bad even though it is almost new? Or maybe i even have cam walk or something. Also my tuner has been tuning gm cars for almost 15 years so he knows what he is doing. he is using efi live to tune with as well. the car really doe sent like light throttle accell know matter what we do with the tune. It will buck and jerk like crazy in first gear if you just try and go slow.

Also could my dummy distributor be installed in the incorrect spot and cause the p0342 and p0343? In the efi live data logger i can se that there is a cam signal for sure because it is counting it. It is pretty much a distributor out of a 01 express van with a 5.7l that has a sealed cap ( no rotor button or dist cap). Only using for a 1x cam signal to the ls1 pcm. If i remember correctly a ls1 car will run with only a crank signal but will have a hard time starting witch it does. It also has a stumble like misfire at light loads witch would make sense. I think the ls pcm uses the cmp to determine if it is on the compression or exhaust stroke on start up and at light load, it also effects total timing i belive. It just has to be something to do with that distributor because the pcm, wiring, cmp, and connectors have all been tested or replaced and are ok. We have had this thing on the dyno for almost 4 days trying to figure out the problem now! the cam that is in the car ran fine with my tuned tpi computer so i don't think it is a cam problem. The only thing that i removed in the front of the engine is the timing chain and i know that is on correctly. I know the 24x ckp is working correctly as well. any ideas???

Got this from alldatapro and was wondering if since i am running a speed density setup without a maf sensor if this could cause a problem? . I know that you can run the ls pcm in speed density only but just figured i would throw it out there.

CAMSHAFT POSITION (CMP) SENSOR

The Camshaft Position (CKP) Sensor works in conjunction with 1x reluctor wheel mounted at the rear of the camshaft. The CMP is used to determine the top dead center position of cylinder # 1, and will synchronize with the 24X CKP sensor signal for quicker starting. The PCM will detect an increase in the Mass Airflow (MAF) Sensor signal when the engine starts. The CMP signals are output as a digital waveform.

This car is still on the dyno and i need to get it figured out asap!!! any help or input would be great!

 

It's possible.

Unlikely, but with improper adjustment you may see a P1345 DTC.

An O-scope would reveal more about what those counts look like. The PCM does not like something about the counts it sees.

It is a 1996-2002 Vortec distributor.

For start up, yes. Light load, no.

I don't think this is true.

I would try an O-scope before a new distributor, but let us know how the distributor replacement goes.

I know of several 24x SBC and LT1 engines not using a MAF sensor and this trouble code is not present.

For one reason or another, you have a camshaft signal waveform problem. It's not related to tuning.

 

We tried to hook up a o scope but for some reason it would not work on my scanner. Im going to try again with a different scanner tomorrow. I had mike at efi connection send me another distributor just to c if it does anything for it. And yes it is a 96-02 vortec distributor. I will have the new distributor on Tuesday so i will keep you posted on what happens.

 

Got it all figured out. The distributor was bad. slid the new one down in and boom she was good as gold! the best part is that mike at efi connection gave me my money back for the new distributor! She just rolled of the dyno tonight with a fresh custom tune. the car put down 342hp and 389tq on a stock bottom end. Not to bad for a dump truck sbc engine lol.