My car hasn't been wanting to start unless jumped. I took the battery and had it tested and Advance said it was good. Then I started the car and disconnected the positive cable and it died which I was told was a sign of the alternator being bad.

I bought a new alternator and charged up the battery for a few hours. I took back the old alternator for the core and had them test if first and they said it tested good but the bearing was going.

Now the car has been starting since the alternator install yesterday but today it intermitantly had that not starting problem just after I adjusted the timing (probably not related?).

I'm reading 12.5V at the battery and when started with the lights, tach, and temp gauge on it'll dip down to 11.5-11.8V range. I disconneced the gauges and still had the same problem. I also had the fan on a switch and disconnected that too. The battery ground on the engine also seems to be good. I'm lost here.

I'm loosing my patience with this car so I hope you all can help.

 

,First off the alternator was probably fine, you disconnecting the positive cable ended up opening the biggest circuit on the car, ie the power SOURCE, so that explains that, when you say starting problem you need to clarify, is it turning over slow? Just clicking? Just not firing? If it just goes "click click click", your cca's on the battery are shot and I bet advance wasn't looking for cca, only voltage which is why any joe can work there, they don't actually diagnose anything, also why are you starting the car with your lights on?? Anyway, if the starter is running fine, and you jacked up the timing, id check over your work because if your starter is cranking at a normal rate then its probly in the fuel or your recent timing adjustment

 

I must have read some bad information on disconnecting the positive cable. The bearing on the alternator was shot though it kept buzzing and squeeking so at least that wasn't a complete waste of money.

I didn't start the car with the lights and accessories on I meant I turned them on after starting, sorry for the confusion.

The car will crank slowly and after enough attempts will just click.

The problem was happening before my timing adjustment, its just that this last time that was the last thing I'd done before that happened. I had a vacuum gauge hooked up and it said my timing was off, I advanced my timing a little and then the vacuum was in the "normal" area and the car ran a little better.

 

you un hook the neg cable first, and always first, and its put on last and always last but thats what you do, remove the neg while running and if the alt is good, it will keep running, its an old trick for a test.

But NEVER remove the pos=+ first, that makes sparks n can blow it up, as battries give off hydrogen gas. Seen it happen, not pretty.

Is it a full electric car? Could be a power seat or window switch, even a cig lighter can do it, if its all gunked up in there. was a rash of old muscle car fires a few back from old cig lighter like that, finally shorting out good enough and buring the cars down to the ground.

 

I don't have power accessories thats why I bought the car (less headache, so I thought). I don't have power windows, locks, etc. I can check if powers going to the lighter. I know the battery should be putting out more than the power I'm getting from the reading. I haven't driven the car in two years, I really only just start it and let it run in my driveway. I did charge it for 4 1/2 hours two days ago though and then everything was fine untill a bunch of starts later it was dead.

 

I just started it up and it started fine, ran it for about 25 minutes and then it wouldn't start after I turned off the car. I'm lost. Is it not charging the battery? How can I tell?

 

the alternator should have a small plug with 2 wires, and a single large wire attached to a post on th back of the alt. The large wire goes to the positive battery cable/battery post. Thats where it charges to. sounds like you dont have it hooked up, or its broken.

 

I have it hooked up. It is routed odd though. There wasn't a post on the alternator it was a flat metal piece with a hole that I put a screw through (I thought it was odd too) and that wire goes to a piece by the radiator and is screwed in there with a circle connector, from that there is another wire mounted in the same location with the circle connector that goes to the battery I believe. I can try to get a pic up.

 

 

I did that. The voltage drops about a volt when the cars on and then slowly creeps up when it's off.

Here are pics of the wire routing. I have no idea what that orange wire that seems to be run with the positive lines is.

 

 

I just uploaded a video of it so you can hear. Kind of a slow cranking and clicks.

http://www.youtube.com/watch?v=ECvZilr4mx8

 

 

I had a guy whos going to college for auto tech tell me it was the distributor but the track record of advice on this site has been right almost all the time so I'll take your advice.

You lost me on thest terminal letters. What is terminal S? I've got the thick red and black wire going to the positive terminal on the alternator and has power because I accedentally touched something and it sparked, the solid red going to the battery and I don't see a brown wire but the orange goes towards the firewall.

This car had an engine swap before I bought it and the wiring isn't as neat as it should be so i'm not sure if some stuff is off with coloring.

 

Well if things are done wrong with no real clue, maybe unhook the batt and fully charge it, then pull every fuse on the fuse pannel, check the battery for drain. If its not, plug things in 1 at a time n check to see what drainin it???

 

I did do the charging the other day. I haven't pulled every fuse though. So I understand you correctly do you mean pull every fuse and try starting it and put one fuse in at a time to see whats draining it?

 

you don't start it but you do turn the key on, while putting each fues in one at a time you watch the voltages of the battery to look for drain.

 

Or you could use a multimeter and just do a parasitic load test, if no parasitic load is present your battery is shot

 

Read through your thread. One thing that I didnt see addressed was the fact that your voltage drops off with the car running. Engine idling, battery voltage should be about 14v. The parasitic load test is a good way to find a light bulb, relay, or motor thats running on, draining the battery when the cars parked, but you need to adress the no charge voltage first. In the large red wire from the alternator to the junction block is a fuse link, its the soft orange portion. Its identified by the large black cylinder where it joins the wire. The wire running from the junction block into the harness terminates at the batt post of the starter. There should also be a fuse link at that end. Youll need to test each leg of the circuit to find the broken fuse link. It looks like you may have some questionable repair to this circuit. The quickest test for this circuit is to check voltage at the alternator post where the wire connects. This post should have battery voltage with the key off. I bet you wont find batt voltage there because the circuit is broken. Also check ground to the block from the batt-. BTW, a note on disconnecting the battery terminal with the engine running. This was okay back in the day of 60 amp alternators. Tody's high output units are way too sensitive to do this to. Its a good way to waste an alternator.

 

Oh one more thing. Be`sure to fully charge the battery before starting the car once youve repaired your wiring. Dumping the load of a dead battery on an alternator can destroy it.

 

FOUND THE PROBLEM!!! Thank you all for helping! I checked every spot you all told me to. We did check part of that fuse link this afternoon and rewired part of it that didn't look so good.

YOU WANT TO KNOW WHAT THE PROBLEM WAS!?!?!

THE DAMN COMPUTER WAS PULLING ALL THAT CURRENT FROM THE BATTERY!


I fixed it tonight and it and once the computer stopped causing to problem the battery went back up to 14V when running.


The problem now is that I had the car running great and now the computer is messing it all up. The idle is choppier, the exhaust sounds like popcorn popping at idle, and it dies when I put it in gear. I adjusted the timing a tad and that fixed the dying in any gear but I don't understand the rest.

 

 

Any idea how expensive that is? Also, can I just run it without the computer and what would I disconnect to do this?

 

 

Dumb question but is the computer on these cars called a PCM, ECU, or what am I looking for? Does it matter if I get one out of a carb'd car or TBI, TPI, etc?

It seems like I already was out of control of those things. I had the car running great when the battery wasn't dead and now it's rough.

How do I tell if this computer is for sure shot? It blew the fuse and I thought that's why it was drawing all that power because when I put a new fuse in the battery was fine and the computer started working. I'm wondering if it's just going to all happen again.

 

The computer is called an ECM or "Engine Control Module". ECU is "electronic control unit" and can refer to any solid state control device. PCM is "powertrain control module" and refers to later units which control the engine and an electronic trans. BTW, I need to read these threads more thoroughly. Nina had already addressed the no charge issue. Also, be careful condemming an ECM. They are often mistaken as the cause of an issue that ends up being caused by something else. It may well be the ECM but even if you spend the money to replace it, if you dont verify that everything else is okay, you could fry the new one. At least check all power and grounds to the ECM. Also good to check harnesses and actuators for intermittent shorts or low impedance. A shorted harness or high current draw by an actuator can overload the drivers in the ECM and cause it to fail. Of course running it on 11 volts not so good either. If you can connect a scanner and read data before replacing the ECM you might find any other issues.

 

I didn't know a scanner could work on an older ECM like this? What type of scanner am I looking to buy?

The car had a really rough and messy engine swap from what I can tell and the wires are a mess, that's why I was thinking of getting rid of the computer. There are so many disconnected wires.

 

 

You only need a paper clip to get error codes, SEARCH

 

Paper clip will work to flash codes but not for reading data. Im worried about this car though. Messy engine swap could mean no ALDL. Sorry, Im at a loss just now. LG4 is that TBI? If the car is carburated, removing the ECM is an option. You would need to replace the carb with a non electronic unit and replace the distributor with any non computer controlled unit. I prefer the earlier style HEIs for this. If its fuel injected, it will not run without an ECM.

 

What is ALDL? LG4 is the low output 305 carb'd motor. I know all about the paper clip, thats all I've used for codes. It seemed like the statement by ASE doc was that a scanner could read data in this computer which is not what I understood to be correct on these cars, thats why I asked what type am I looking for.

 

Well if you use winALDL or similar it often useless for that, I ran through the gambet of bad ECM stuff and none of that helped, only cue in was the flashing codes, and the constant strobe of bad or wrong chips.

unhook battery and pull ecm and open it. look for anything burnt.

But note a new computer ins't that much and you get a 1yr warranty with em.

I used rockauto and had no problem with an exhance, 1 days before it expired.

 

ALDL is the 12 pin diagnostic connector under the dash, just below the steering wheel. If youve used a paper clip to read codes, you jumpered pins A & B of this connector. An OBD1 scanner will read data from your ECM through the ALDL. This is always my second step in diagnosing a vehicle, right after reading codes. Data can point out a bad sensor or circuit and help verify the cause of a code.

The scanner I use for this at work is a Snap On MT 2500, otherwise known as the "brick". Theyve been discontinued and are available used for about $300-400. Its worth buying one if youre going to own a computer controlled vehicle.

Your engine is carb'd which means you can easily swap to a non-electronic carb and distributor and not have to deal with the ECM. Your photos show what looks like alot of questionable repairs and mods. In fact I think I see the AIR management connectors hanging down below the exhaust manifold, along with twisted off AIR pipes in the same man. Making the CCC (computer command control) system work properly and reliably may be a real task. Going non computer may be an easier option.

An earlier, non computer Q-jet carb will bolt on to your manifold. Look for one from a chev V8 for the right linkage configuration and you may have to do some fabricating for the TV cable linkage. An HEI distributor from a 77-81 chev V8 will also be a good start.

One thing that will help you greatly is to have good wiring and diagrams for your car. Whether you go away from CCC or choose to repair it, youre going to need good information on your vehicles engine harness. If you go with an earlier Q-jet it will also be hlpful to have vacuum diagrams for both the donor vehicle and yours. Also a basic understanding of engine controls and the difference between ported and non ported vacuum.

Going non computer means you can eliminate alot of the damaged wirng on your motor. A good diagram will show you what you can remove and help in cleaning up your engine bay and making your electrical system reliable. Whichever way you choose to go, good luck