davidflrs
08-07-2011, 06:17 PM
I have a 91 525i with an m50 motor.. I installed a turbo about a year ago and had to relocate the battery to the trunk. I purchased a new battery at the same time.
The car started fine but if I didn't use the car for about 2 weeks car wouldn't start. It wouldn't crank. I would either jump the car or remove the battery and charge it and the car started and worked perfectly.
So I assumed the battery was not holding the charge and brought it back to autozone. They tested the battery said it was fine and charged it out of courtesy for me that is wasn't at full charge but the battery itself would hold a charge properly. I have taken it to them twice after to have it checked. Months pass and the night before every autocross I have to remove the battery and charge it overnight.
This weekend was no different. I drove to the track and unloaded the car in prep for tech inspection only to have the car not start again (no cranking)as if the battery had low charge. I jumped the car it started and I brought to the have the battery replaced. they tested it again said it was fine and replaced it with a new one at my request. I installed the new one and car still wouldn't crank.
The battery was tested and had Cold Cranking Amps of 815 and should have been enough to crank the car. Does the m50 need higher CCA's? The Alternator works fine at 13.9 while idling. The starter cranks quickly and the car starts perfectly when jumped. Would a faulty starter only work if 2 batteries were attached? I know it isn't a fuel delivery or spark issue because once it cranks it starts. If the solenoid on the starter went it should still not start when jumped unless I tap on it right (assuming its humid and the solenoid is sticking)? Could a grounding issue from moving the battery to the trunk be the cause? If my starter isn't properly grounded then why would it start when jumped? or Do I have to do a better grounding job for my battery and it only starts when a properly grounded battery jumps it?
Not really sure where to start (no pun intended) any help would be appreciated.. My next race is next week and I have to compete in all remaining races now to qualify for season standings.
The car started fine but if I didn't use the car for about 2 weeks car wouldn't start. It wouldn't crank. I would either jump the car or remove the battery and charge it and the car started and worked perfectly.
So I assumed the battery was not holding the charge and brought it back to autozone. They tested the battery said it was fine and charged it out of courtesy for me that is wasn't at full charge but the battery itself would hold a charge properly. I have taken it to them twice after to have it checked. Months pass and the night before every autocross I have to remove the battery and charge it overnight.
This weekend was no different. I drove to the track and unloaded the car in prep for tech inspection only to have the car not start again (no cranking)as if the battery had low charge. I jumped the car it started and I brought to the have the battery replaced. they tested it again said it was fine and replaced it with a new one at my request. I installed the new one and car still wouldn't crank.
The battery was tested and had Cold Cranking Amps of 815 and should have been enough to crank the car. Does the m50 need higher CCA's? The Alternator works fine at 13.9 while idling. The starter cranks quickly and the car starts perfectly when jumped. Would a faulty starter only work if 2 batteries were attached? I know it isn't a fuel delivery or spark issue because once it cranks it starts. If the solenoid on the starter went it should still not start when jumped unless I tap on it right (assuming its humid and the solenoid is sticking)? Could a grounding issue from moving the battery to the trunk be the cause? If my starter isn't properly grounded then why would it start when jumped? or Do I have to do a better grounding job for my battery and it only starts when a properly grounded battery jumps it?
Not really sure where to start (no pun intended) any help would be appreciated.. My next race is next week and I have to compete in all remaining races now to qualify for season standings.