Ok I have a very strange intermittent no start issue I think I’ve narrowed it down to the cam. Trying to follow the no start chart when I can but it never seems to do it for more than one crank inside the garage. So my question is when checking voltage readings at the cam sensor and module its one volt lower than what it says to look for 5.1 at the cam and 11.5 at the module when I have 12.5 at the battery so is this low enough to be out of the 6-9 volt range on the chart?? So would this mean a wire issue ??
no start diag. help
- Thread starter justamatt
- Start date
darkred87T
Active Member
- Joined
- Oct 27, 2003
Im not sure what you're getting at with the cam. Your'e saying you have an "intermittent no start" issue? Can you elaborate?
BlackBandit
God loves Buicks!
- Joined
- Mar 29, 2003
You could try cleaning your grounds (the one from the battery to the block and the ones from the head to the firewall) and your battery terminals and see if that fixes the voltages. I doubt the voltages in and of themselves are your problem though. Could you explain a little bit what happens when you're trying to start the car? Is there a pattern of no starts like every time it sets for x amount of time it won't start or is it truly intermittent?
Ok well this is the story its been about 3k on a rebuild prior to rebuild everything worked just fine i had replaced the computer and coilpack prior to rebuild. Part of the rebuild included a caspers cam sensor, the no start would only occure after the car was hot at first and would only take about 5 minuts with no check engine light so i naturally assumed it was the module and installed a duralast (no change) and when dead no rpm signal so after reading up decided to replace the crank sensor (no change) after a while it started setting a code 41 (getting more frequent) and doesnt seem to care if the car is warm or not but only no starts most of time for one crank attempt or for just a second keeping me from being to diagnose it in the garage. a couple days ago it left me stranded for about 30 minuts. the only cheap part is the module so im gonna have my old one checked this weekend and put it back on but im guessing its the cam sensor sorry for the long write up
BlackBandit
God loves Buicks!
- Joined
- Mar 29, 2003
I would start by checking all of your wiring connection/grounds and re-adjusting the cam sensor with the above process.
darkred87T
Active Member
- Joined
- Oct 27, 2003
Starter Motor?
If I understand correctly, I don't think he has a no crank issue, but rather no start.
The plot thickens
On the way home today it actually died on my and wouldnt start for 20 min rechecked the voltages and they are still at 5.1/11.5 checked the grounds all had over 12 and then pulled a plug #1 had no spark checked for open circuit 839 and had no continuity
On the way home today it actually died on my and wouldnt start for 20 min rechecked the voltages and they are still at 5.1/11.5 checked the grounds all had over 12 and then pulled a plug #1 had no spark checked for open circuit 839 and had no continuity
- Joined
- Feb 18, 2006
CODE 41
Trouble Code 41 indicates that the Camshaft Sensor is not functioning properly.
The ignition module uses the Cam Sensor signal for timing the spark firing. The ignition module also passes this signal to the ECM to enable sequential fuel injection. The inability to properly determine engine position from the Cam Sensor will generate Code 41.
The engine will continue to run if the signal is lost from the sensor, however it will not restart after shut down. If the Cam signal from the ignition module to the ECM is lost while running, the ECM will switch to the simultaneous fuel injection mode. The engine can be re-started but will continue to run in the simultaneous mode as long as the fault is present.
The conditions for setting this code are:
the engine is running, and
the Cam Sensor signal is not received by the ECM in the last 1 second interval
Typical causes for this code include:
1) Loose or misadjusted Cam Sensor
2) Defective Cam Sensor-to-ECM connections
3) Defective ECM
Cam sensor installation and adjustment procedures call for very exact tolerances. It is for this reason that it is recommended that the service manual be consulted while performing any adjustment or replacement of the Camshaft Sensor.
Trouble Code 41 indicates that the Camshaft Sensor is not functioning properly.
The ignition module uses the Cam Sensor signal for timing the spark firing. The ignition module also passes this signal to the ECM to enable sequential fuel injection. The inability to properly determine engine position from the Cam Sensor will generate Code 41.
The engine will continue to run if the signal is lost from the sensor, however it will not restart after shut down. If the Cam signal from the ignition module to the ECM is lost while running, the ECM will switch to the simultaneous fuel injection mode. The engine can be re-started but will continue to run in the simultaneous mode as long as the fault is present.
The conditions for setting this code are:
the engine is running, and
the Cam Sensor signal is not received by the ECM in the last 1 second interval
Typical causes for this code include:
1) Loose or misadjusted Cam Sensor
2) Defective Cam Sensor-to-ECM connections
3) Defective ECM
Cam sensor installation and adjustment procedures call for very exact tolerances. It is for this reason that it is recommended that the service manual be consulted while performing any adjustment or replacement of the Camshaft Sensor.
so could a bad crank sensor connection throw this code? ive check the connections a thousand times to the cam and im pretty confindent they are good additionally ive checked that the cap and sensor body are tight and good and she runs great all the way through third until the svc light comes on then she is just kinda lacking in power
- Joined
- Feb 18, 2006
Crank sensor? (edit) Maybe..... Let me re read the whole thread and think about it
Have you removed the cam sensor cap and checked the reluctor wheel? The tab can break causing the wheel to move.
How about a different sensor cap all together. Do you have access to one?
You may have checked these already. Just throwing a couple ideas to you.
Good luck
ive checked the cap the wheel was tight and no witness marks on it i havent yet changed the cap cause the backup one is a stock style and getting to TDC is a pita additionally i was told that the caps either work or they dont work and that its not the problem ie not intermittent
forgot to mention its a caspers cap with the led built into it
forgot to mention its a caspers cap with the led built into it
- Joined
- Feb 18, 2006
After re reading your first post, the crank sensor could be a possability although, I have never seen one set a code. Usually the car will not start at all. (No spark) or have drivability issues (Missing or stumbling)
Your car running good until the code 41 is set still leans me toward the cam sensor.
Your car running good until the code 41 is set still leans me toward the cam sensor.
- Joined
- Feb 18, 2006
You don't have to have it at TDC. You can just swap it right out.
I bet thats your problem right there.
Swap it out and let us know.
