Problem after cam install

**blownh2x** · 03-17-2010, 05:22 PM

I'm having a problem months and many miles after a cam install on my LS1 motor. The RPM gauge is not functioning anymore. The gauge works on initial start up, but fails a minute or so later. I have already replaced the Cam Sensor figuring that is why it was acting erratic. No luck with that - acts the same. How does the sensor read the camshaft exactly? Could the cam be moving somehow? I'm getting ready to check and make sure nothing came loose next weekend, but figured I would check if anyone has had this problem. Car starts and runs fine with no abnormal noises.

I have the hot cam, double roller timing chain, chrome molly push rods, LS6 springs, and other normal bolt-ons.

**Damian** · 03-17-2010, 08:17 PM

Crank position sensor also has a role in this as well. If that doesn't fix it, either the tach pulses are dead in your PCM (had this happen to me once) or the actual motor inside the gauge cluster went out.

Instead of throwing parts at it and wasting money, have somebody with a Snap On Solus or Tech 2 scanner confirm your problem. Either of those scanners have the capability to find it.

**blownh2x** · 03-18-2010, 05:35 AM

If the tach pulses are dead, will it read a RPM on my programmer? My service engine soon light comes on after awhile for no RPM input (what ever the code is for that). So I figure the ECM has no input and changed the cam sensor. If the crank sensor was bad I figured the car wouldn't start or run pretty bad.

**02fbody35th** · 03-18-2010, 01:48 PM

I dont think your engine would run properly if the ecm doesnt recognize the cam position. so i dont think it is the sensor.

**importhater81** · 03-18-2010, 02:15 PM

Probably unrelated to the cam install.I'd get it scanned...could be just a gauge problem

**bills98ta** · 03-18-2010, 02:25 PM

Might try re-seating the plug connectors on the ecm too.

**importhater81** · 03-18-2010, 04:00 PM

I knew that name sounded familiar.BlownH2X weren't you a member on TeamBajaMarine.com....Sorry man didn't mean to hi-jack your thread.

Like above post said check your pcm connections as well,especially if it was removed to be tuned.Sometimes the weatherpack seals can keep the connectors from seating all the way.The rpm's are calculated by the pcm via crank sensor input and sent to the IPC through a serial data cicuit.Could be a crank sensor or internal pcm issue.

**blownh2x** · 03-19-2010, 12:38 PM

Originally Posted by importhater81

I knew that name sounded familiar.BlownH2X weren't you a member on TeamBajaMarine.com....Sorry man didn't mean to hi-jack your thread.

Like above post said check your pcm connections as well,especially if it was removed to be tuned.Sometimes the weatherpack seals can keep the connectors from seating all the way.The rpm's are calculated by the pcm via crank sensor input and sent to the IPC through a serial data cicuit.Could be a crank sensor or internal pcm issue.

I am/was a member on teambajamarine. Great site and guys on there. I had a baja with a procharged big block. I'll check the PCM connections to make sure, but I never touched them. The car is programmed using a predator programmer with a custom tune. I'll try re-tuning it also. It's weird because it works and doesn't work. thanks for all the help.

**blownh2x** · 03-28-2010, 04:06 PM

I found the problem and looking for some information. The cam retaining plate actually broke; therefore, the cam was floating back and forth a little and destroyed what looks like a bearing. My main question now is:
1.) what goes between the retaining plate and the cam? some sort of bearing?
2.) is there a bearing between the cam and timing gear?
3.) should I get these parts from the dealer or somewhere else?