I had to disconnect my battery yesterday to replace my valve cover gasket and crankcase breather tubes. The body to engine grounding strap had to come off too. After I was finished, I hooked it back up and tried to start, but it hesitated and started hard on the second try. The battery is about 1.5 years old and sounded nearly dead.. What gives?
Hard start after reconnecting battery?
- Thread starter dlundblad
- Start date
- Status
Bad connection? Clean your terminals ?
JHZR2
Staff member
What was the battery voltage? I'd suspect poor connection, but did it improve after the first couple times? If so, it may have just been the conputer re-learning something.
You sure no breathers/vacuum lines were out of place?
You sure no breathers/vacuum lines were out of place?
When a battery is disconnected, I believe the ECM reverts to its default mode, losing memory for fuel trim and all the other things it's learned about how to make its particular engine perform best.
With a 12 year-old car, the default modes may no longer be the best match and hard starting and driveability issues could result. It should relearn very quickly though and not be an enduring problem.
With a 12 year-old car, the default modes may no longer be the best match and hard starting and driveability issues could result. It should relearn very quickly though and not be an enduring problem.
I assume its the ECM relearning, but would not hurt to double check the battery and ground connections. Maybe wirebrush.
Originally Posted By: mulehead
Yea the computer has to reprogram it self .
Yea the computer has to reprogram it self .
I'll never undo any electrical connection anywhere without a spray can of Caig Deoxit D5 on hand to remove all that resistance causing oxidation which cannot be seen by the naked Eye.
CRC QED cleaner was used profusely on a suspect connector's pins and sockets along with some mechanical means to really clean them out well. The Deoxit D5 was then applied on the pins and barrels os said suspected connector, which appeared pristine after the CRC, blackened many a q tip and applicator as pins and sockets took on a oily chrome finish.
I'll Use Caig DeOxit Gold on some connectors after a D5 cleaning, and Deoxit Shield on ones near a flooded battery terminal, or those exposed to similarly corrosive environments.
I'll use Dielectric grease on the exterior of connectors only for repelling moisture, but Dielectric grease will never be mashed into any connector again and reseat the connector.
My suspect connector which was first cleaned to 'pristine' with the CRC QED, but then really cleaned with the Deoxit, was heavily oxidized despite a liberal application of quality dielectric grease from the factory and my subsequent removals and reinstallations.
I'd urge anybody with any intermittent or suspected connector issue to pick up some of this product and follow the directions. The QED cleaner is good for flushing out old grease and contaminants, but treat the actual electrical contacts with the Caig D5 afterward.
CRC QED cleaner was used profusely on a suspect connector's pins and sockets along with some mechanical means to really clean them out well. The Deoxit D5 was then applied on the pins and barrels os said suspected connector, which appeared pristine after the CRC, blackened many a q tip and applicator as pins and sockets took on a oily chrome finish.
I'll Use Caig DeOxit Gold on some connectors after a D5 cleaning, and Deoxit Shield on ones near a flooded battery terminal, or those exposed to similarly corrosive environments.
I'll use Dielectric grease on the exterior of connectors only for repelling moisture, but Dielectric grease will never be mashed into any connector again and reseat the connector.
My suspect connector which was first cleaned to 'pristine' with the CRC QED, but then really cleaned with the Deoxit, was heavily oxidized despite a liberal application of quality dielectric grease from the factory and my subsequent removals and reinstallations.
I'd urge anybody with any intermittent or suspected connector issue to pick up some of this product and follow the directions. The QED cleaner is good for flushing out old grease and contaminants, but treat the actual electrical contacts with the Caig D5 afterward.
Caig Lab products are mentioned in the service manuals of companies such as HP, Tektronix and Collins Radio. I use the stuf on every tube pin in my Collins Radio gear.
Depending upon the vehicle there may be a specific process for restarting the car after disconnecting the battery.
Our Subaru starts hard and idles extremely poorly, and will stall at every stop unless the correct procedure is followed to allow the computer to relearn the settings. It takes about 10 or 15 minutes to follow the procedure, or an hour or so of driving time.
Our Subaru starts hard and idles extremely poorly, and will stall at every stop unless the correct procedure is followed to allow the computer to relearn the settings. It takes about 10 or 15 minutes to follow the procedure, or an hour or so of driving time.
JHZR2
Staff member
Originally Posted By: wrcsixeight
I'll never undo any electrical connection anywhere without a spray can of Caig Deoxit D5 on hand to remove all that resistance causing oxidation which cannot be seen by the naked Eye.
CRC QED cleaner was used profusely on a suspect connector's pins and sockets along with some mechanical means to really clean them out well. The Deoxit D5 was then applied on the pins and barrels os said suspected connector, which appeared pristine after the CRC, blackened many a q tip and applicator as pins and sockets took on a oily chrome finish.
I'll Use Caig DeOxit Gold on some connectors after a D5 cleaning, and Deoxit Shield on ones near a flooded battery terminal, or those exposed to similarly corrosive environments.
I'll use Dielectric grease on the exterior of connectors only for repelling moisture, but Dielectric grease will never be mashed into any connector again and reseat the connector.
My suspect connector which was first cleaned to 'pristine' with the CRC QED, but then really cleaned with the Deoxit, was heavily oxidized despite a liberal application of quality dielectric grease from the factory and my subsequent removals and reinstallations.
I'd urge anybody with any intermittent or suspected connector issue to pick up some of this product and follow the directions. The QED cleaner is good for flushing out old grease and contaminants, but treat the actual electrical contacts with the Caig D5 afterward.
Slightly OT, but why d5 then gold? Don't both have cleaning action?
And why not the d100L which has more cleaning?
I'll never undo any electrical connection anywhere without a spray can of Caig Deoxit D5 on hand to remove all that resistance causing oxidation which cannot be seen by the naked Eye.
CRC QED cleaner was used profusely on a suspect connector's pins and sockets along with some mechanical means to really clean them out well. The Deoxit D5 was then applied on the pins and barrels os said suspected connector, which appeared pristine after the CRC, blackened many a q tip and applicator as pins and sockets took on a oily chrome finish.
I'll Use Caig DeOxit Gold on some connectors after a D5 cleaning, and Deoxit Shield on ones near a flooded battery terminal, or those exposed to similarly corrosive environments.
I'll use Dielectric grease on the exterior of connectors only for repelling moisture, but Dielectric grease will never be mashed into any connector again and reseat the connector.
My suspect connector which was first cleaned to 'pristine' with the CRC QED, but then really cleaned with the Deoxit, was heavily oxidized despite a liberal application of quality dielectric grease from the factory and my subsequent removals and reinstallations.
I'd urge anybody with any intermittent or suspected connector issue to pick up some of this product and follow the directions. The QED cleaner is good for flushing out old grease and contaminants, but treat the actual electrical contacts with the Caig D5 afterward.
Slightly OT, but why d5 then gold? Don't both have cleaning action?
And why not the d100L which has more cleaning?
- Status
