Alternator not charging battery, and car will not go over 20 mph
Need suggestions?
I have a 90 240sx and i got it about a year ago and sadly it sat up for a year with no battery. It has many electrical problems. For one, i put a new battery in and the alternator will not charge it. I took it off and got it tested, and its perfectly fine. I checked the alternator fuse it was fine. Im clueless.. The timing is badly off, it hesitates to go and will not get over like 20 mph. I was told maybe the ECU is messed up due to have been sitting up so long with out a battery.. Maybe their separate problems or its the ECU. Does anyone have any other suggestions or believe it is the ECU? Or just any help at all?
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Hijacker
- Posts: 14373
- Joined: Wed Aug 13, 2003 4:57 am
- Car: '92 240sx Convertible
'94 F-150 - Location: Fredericksburg, VA
They're probably seperate issues. The ECU has no relavence over the charging system
What I would do is download the service manual and start testing wires on the alternator. It could be a bad/missing ground. The ring terminals on the bottom/back of the alt would be the biggest culprits to me. Especially if the alt tested fine. A lot of people lose the small 8mm headed bolt that holds one of the ring terminals to the alt.
As for the hesitation problem. I would first get the car back in time. Also, does the car refuse to go over 2500 rpms? If so, I would start looking at a possible bad MAF. Corrosion, bugs, weather could have damaged it. And when it's damaged the ECU enters limp mode and the car can't accelerate or go over 2500 rpms.
ECUs typically don't go bad from sitting with no charge. We have a ton of cars on this site (motor swaps, etc) that are using ECUs that sat around for years with no battery hooked up to them.
What I would do is download the service manual and start testing wires on the alternator. It could be a bad/missing ground. The ring terminals on the bottom/back of the alt would be the biggest culprits to me. Especially if the alt tested fine. A lot of people lose the small 8mm headed bolt that holds one of the ring terminals to the alt.
As for the hesitation problem. I would first get the car back in time. Also, does the car refuse to go over 2500 rpms? If so, I would start looking at a possible bad MAF. Corrosion, bugs, weather could have damaged it. And when it's damaged the ECU enters limp mode and the car can't accelerate or go over 2500 rpms.
ECUs typically don't go bad from sitting with no charge. We have a ton of cars on this site (motor swaps, etc) that are using ECUs that sat around for years with no battery hooked up to them.
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Vegascorbin
- Posts: 732
- Joined: Sat Nov 24, 2007 9:56 am
- Car: 1990 240sx dirt track race car
Re: Need suggestions? (j-rad)
Did you put fresh fuel in before trying to start?Year old fuel will cause problems.
Re: Need suggestions? (j-rad)
Low battery voltage can cause some strange issues. I would get the car charging first then sort out any drivability issues. Yes dont overlook bunk fuel.
Re: (Hijacker)
Well now that i think of it yeah it wouldnt get over about 2500rpms. And i dont know what the MAF is.. and if i fix or clean the MAF with the ECU get out of limp mode?
And yes i changed the oil and old gas..
Modified by j-rad at 10:13 PM 5/30/2008
And yes i changed the oil and old gas..
Modified by j-rad at 10:13 PM 5/30/2008
Re: (j-rad)
MAF is your Mass Air Flow sensor. It's the sensor between your air filter and your throttle body. I've seen bad ones make the vehicle act like it's got a really low rev limiter.