so i've just put a new engine and and I driven her a couple times. tonight I went to go for a drive to see if everything is working properly cause I'm safetying it tomorrow. it was producing very low voltage, maybe 9.5-11 volts. normally makes upwards of 13 idling at 800. It was raining and its the first time I've had her running in the rain. do you think the moisture in the air could have something to do with it? when I come up to a stop sign and push the clutch in and she drops to idle all the lights go real dark, my headlights go really dim and then brighten up a little again. I'm 99.99% sure the alternator wasn't slipping or anything, it was pretty dry and i couldnt hear any belt slip. I really don't like it running like that. maybe I have a failing alternator (but its a new "reman" champion one, 78amp) or maybe the battery doesn't hold charge properly? (its also a new delco unit, for a full-size olds).

also, when I turn the car off, sometimes the needle will spin to the wrong end of the guage (redline side) and stay there. when I turn it on next time I have to rev the car to about 1500 or more to break the needle free and bring it back down.

Last thing, only happened today, when I turn the car off and put the key to the acc or off position the "brake" light and "fasten seatbelt" light in the dash slowly slowly fade away, they don't turn off. and as they do that, the choke light turns on and stays on even with my key out of the cylinder. how can this happen, that light has never even been on before, I have a holley 4150 w/ a manual choke, it wouldn't know even if the choke WAS engaged. I'm going to try tomorrow again and see what happens, but I'm not fond of these sketchy electrical problems that randomly show up.

 

 

so I load tested the batt and tested the alternator. heres what happened. I had charged the battery over last night, so she started up fine but all the electrical things like windows, lights, turn signals, defroster, heater whatnot all we really lowering the voltage. I checked the batt and it had a proper higher 12 volts across it. nobody was there to help me with the load test, so I ran her for a bit and then disconnected the batt negative. she still ran and all the electrical worked fine, almost better than before. my lights were brighter and everything worked properly and was on steroids when I revved her but you could obviously tell as you turned more and more stuff on the alternator feeling every impact. anyways, because everything ran I suspect the alternator is Fine? I turned it off. when I went to go start it again the battery Struggles to turn her over, cranks really slowly and you can see all the lights in the dash go so dim they're pretty much on and off between cranks. clearly the batt was struggling, so i thought the batt was funky and would definitely fail the load test. just in case I had someone come out and test the batt. It passed the load test fine, just over 10volts cranking, It also turned over at a reasonable rpm without dimming all the lights this time.
why the sudden change?
after that the voltage guage slowly climbed to 13 and all my lights were bright as they should be, seemed to be running fine. I'm leaving the batt in there overnight, if its dead tomorrow i suspect an electrical leak. otherwise I can't explain why sometimes she cranks over and runs like a champ and a moment later barely gets along.

so:
alternator test: Pass
Batt Load test: Pass (at the time?)

one other new symptom. when I took her out last night I was having less than acceptable voltage readings. at one point I launched her hard and after the acceleration was over my voltage was pretty much non-existent. my headlights went out, my guages went ultra-dim. all my guage needles were spazzing out. as I drove closer and closer to home the lights flickered on and off as i slowly built up voltage. why? why why why why why? this doesn't make any sense to me. you would think with the high rpm's the alternator would make tons of energy.

 

 

I found a loose ground, it wasn't even fastened. it dropped in to where the tranny tunnel is and that why I didn't see it. I'm going to go and ground it somewhere and we'll see if that helps with anything. all my connections seem to be good, they're all fresh as I just installed everything.

Driving back from the safety test today I noticed the voltage drops when the car experiences some form of acceleration, either stopping or even going around a turn sharply. it bounces back quickly, but that doesnt seem normal.

 

A couple of thoughts.

There is supposed to be a ground connection from the firewall to the back side of the block on the passenger side. In the attached photo, it is the braided copper conductor. The back conductor is the alternator ground for the 82 model year. If this is the loose ground you are referring to, make sure it is connected to the firewall and the block.

As Nina stated, a loose ground connection can cause all types of electrical problems.

Also have you checked the following items? The condition of the alternator belt. Is it worn or frayed. Is the alternator pulley loose? What about the alternator itself. Is it securely held in its mounting brackets? What about the alternator belt tensoin? If is is omewhat loose it will slip under acceleration or other heavy load, but work just fine under normal load.

 

those are the two wires that I had found were loose and hanging. I grounded them to the firewall but I'm not sure how great a job I did of grounding them. I'm going to reground them when I have some time. The alternator, battery, belts, everything is all brand new. I had the alt on loose at first but heard the belt slip on acc. so I tightened it up a while back. everything in that department is good. as it turns out, when i start driving my voltage is good, sits at about 13volts. sometimes a pinch more or less but as I continue on driving it drops down to 10-11. usually as the engine heats up.

Also, it doesn't particularly want to go up past 4500 rpms. do you think this could have something to do with the voltage being so low that at those speeds the coil cant properly charge fast enough and I'm not getting sufficient spark?

 

You might want to verify that the ground wires are not loose, both at the firewall screw and on the block. You should also make sure that the wire ends that were hanging down are clean. If they have a film of oil or dirt on them you will not get a good ground connection. If you think that the engine heat is causing a problem, then drive the car until it is nice and warm in the engine compartment, and your voltage is dipping. Then have it tested at the parts store. The first time you had it tested, was it on or off the car?

I seem to remember reading in one of the other sections that someone was having problems with the rpm being limited. He discovered that his catalytic converter was shot and very clogged. So the back pressure on the exhaust system limited the engine rpm. I don't know if a voltage in the 10-11 volt region would limit rpm because the coil can't charge. Hmmm...do you have an HEI distributor? Again, I am not sure if a slightly low voltage would limit rpm.

 

unfortunately I don't even have a cat. the owner before me had a custom exhaust built without a cat. maybe the muffler is clogged or something? when I pushed it in first to see what would happen, it would pull to about 3700 and then I could feel the power drop off untill 4500 where it stuttered for a second and fell down to 3500. all while I had the throttle wide open. so it managed to drop rpm's at wot.

 

OK

Here is some trouble shooting info from the 82 Service Manual. You want to review Item 9. You should be able to do a., g. and h. Note that h. is a method to determine if the exhaust system is clogged.

All of the other items will require that I scan a number of pages, which I do not have time to do right now. Try a., g., and h. and see if addressing them may solve your problem.

You also need to verify that you ground connections are good, as that was the basis of the original question.

 

I re-did some grounds the other night, but haven't driven since. I'll probably use a multi-meter to check them all soon. the air cleaner is brand new, so are the plugs. (well, the plugs aren't new they've been around for a couple years but never been used, still in the boxes, some normal delco ones, nothing fancy) but i'll check the plugs anyways, maybe somethings up and i missed it. as for the last test to check the clogged exhaust, can you use the vac port on the holley carb baseplate as opposed to the intake manifold? they should read the same right? and if they don't you're looking to see if if changes, not the actual value of the vacuum reading.

as for scanning other pages, thanks alot for scanning that one, I have a service manual from an '83 T/A my dad used to have back in the day, they're probably very similar, maybe the same info is in that manual.

 

I guess you could use a port on the carb, but I am no expert in that area. Yes, you are looking for no change in vacuum pressure if the exhaust system is good, and a drop in pressure indicates you should check the exhaust system. I would expect the muffler(s) to be the culprit.

Yes, I would expect you Dad's manual to have the same basic information. However if anything changed from 82 to 84 teh 84 maual would have the revsions/updates.

 

I re-did some grounds, sanded them all down and made sure there was real nice contact. I was able to get past 4500. I got to about 5200 in 3rd on an on-ramp but didn't push it much farther. last time I tried to get past 4500 it was in 1st. maybe the load makes a difference i'm not sure, but I performed that vac test and the vacuum was constant, so the exhaust is fine.

The voltage has been staying pretty steady, usually right on 13volts sometimes down to 12 and occasionally up to 13.5-14 when the car is cold and whatnot. but she overheats on the highway, or any extended time over 2000rpm. I noticed the shaking/vibrations increase through the shifter once i got up to and past 2000. also makes a weird noise, kind of like like a knock, but its not detonation. Maybe my timing/advance needs to be adjusted? I haven't played with it cause I don't have a timing gun. but she overheats at higher rpms, the coolant is full, oil pressure is usually around 300 kPa although at idle and slower rpms (1500 or less) drops to 200kPa. maybe theres something i can add to the oil to make it more slippery or something? maybe theres a clog in my rad? do you know of any way to check the coolant temp besides the guage? I stuck an oven mean thermometer through the fins of the rad but it only reads about 160-175 deg.F. I Know thats wrong. I'm stumped. the air dam under the car is there. the fan works. can gas quality cause overheating? unlikely right?

 

Well at least you got the grounds fixed and the voltage seems to be stable. It may vary from time to time by a volt or so, and I would not worry about that. It also appears, based you the vacuum test that you exhaust system is fine.

The voltage has been staying pretty steady, usually right on 13volts sometimes down to 12 and occasionally up to 13.5-14 when the car is cold and whatnot.

For the overheating problem, you might want to post a query in the Cooling board. Give them a more detailed description of what you did when you put the new engine in. Did you remove the existing radiator? If not, remove the top fan shroud and inspect the front of the radiator. You may find some interesting stuff there that has collected over the years. This stuff will block air flow through the radiator and cause the car to run hot. did you reuse the old radiator? Did you take it to a radiator shop and have them pressure test it and clean it? Have you replaced the radiator cap, o ris it the original one?

As for the "noise like a knock" problem post a question in the Tech/General box. There are quite a few folks there that are much more knowledgeable about those types of problems.

 

The rad and shroud were all replaced. I bought the car without any of those and got a stock rad from a buddy and a shroud/electric fan from a buddy as well, all stock off a 3rd gen. as for the voltage, it stays constant most of the time, doing alot better, but it will randomly just go down the drain instantly for a little bit then come back. you think something is shaking loose or something? my grounds are as follows: from the alt bracket, on the pass side front wheel well, on on the back of the block to the firewall and one black wire on the firewall also on the back, the two that were in the pic posted earlier, maybe there are more grounds? also, my alternator gets hot when my car is off, maybe theres a short in there ot something? I can put my hands on the headers and they're cool, but the alternator is really, really hot.

 

Are you using under drive pulleys?

 

nope, stock pulleys.

 

Either your alternator isn't spinning fast enough, or its gone bad. I would pull it and have it tested (Auto Zone will do it for free).

Let us know the results.

 

I was thinking about that, but then it would never register 14 volts. I had it replaced the other day with a new one, but the problem persists.