440 still wont idle for more than a minute

[cudaken]

69 I am weak when it comes to electrical problems but I give it a try.

Where are you taking your reading from, back of Alternator or some other point? Have you had the alternator tested?

I have a friend that has a 70 Challenger R/T S/E that 440 kept fouling the plugs with a stock 750 Holley. Told me he thought the 750 was to much carb for the 440. I told him it was not be he would not listen so I got the carb for free. I did ask about his alternator and had he had it checked? Said he was sure it was not the problem Because it was new!

Installed the Carter AVS, guess what happened? Plugs kept fouling out. Finally he checked the alternator, it was weak. Replaced it and problem was gone. Eric at the time was still running points so it kept running.

Now what makes me wonder at the beginning you had to many volts now you have to little?

Cuda Ken

[firefighter3931]

The MSD box requires at least 10v to fire so your problem is electrical...either the alternator or voltage regulator.


Ron

[69dodge383]

Voltage reg is new. Like a week old. It is working since my volts were at 18 and now they are around. 14/15.

What wud make an alternator do this?

I will say when my 383 was in the car. Maybe cause it has a points distributor and the orig type coil. I never had this issue. Had the older durlast battery and the same alternator. Maybe I did not notice the drop in power because the old dist and coil didn't need as much power to operate correctly. Maybe this issuje has always been with my car. It has just been magnified with the latest changes.

N e way to test the alternator at home? Or does this mean a trip to advance auto?

[69dodge383]

69 I am weak when it comes to electrical problems but I give it a try.

Where are you taking your reading from, back of Alternator or some other point? Have you had the alternator tested?


          I am going to get the alternator tested. I have another one that is the same exact alt in my attic and may give that a shot also.  


   The last reading pulled was off 12v source wire that was the old coil wire. Like I said, this wire shows correct voltage at idle and then just loses enough power and car stalls dies.

[firefighter3931]

Just because the voltage regulator is new doesn't mean that it's not defective. I've seen many parts that didn't work right out of the box. 

The wierd part is that the voltage starts off normal then begins to drop until there is insufficient power to keep the MSD box firing. 


Ron

[69dodge383]

Keep in mind..it didnt like taper off.  It just cut off the volts and the motor died. The car starts right back up when it dies like this. Same symptom. Even with the old voltage reg that was allowing an 18v chg

[cudaken]

69 Dodge, I have heard of that problem before. Sounds like the alternator has a bad diode. As current pass through the diode it warms up, that increases resistant and then they stop working. But other things could come in to play from under the dash.

Here is what I would try. First you need to keep the motor running, how hard would it be to hot wire the MSD to the battery? If you can do it, run the car and test from the back of the alternator, the + wire / big bolt. If it drops there, that is your problem. I would clean it and make sure the nut is tight! Sometimes the stupid little things will bite you on the ass. 

If the voltage does not drop at the alternator then it is something under the dash. Are you using the stock alternator gauge? If so, I would pull the wires and hook them together and test at the wire you have been using. If you are using a aftermarket gauge, by pass it.

Next, I would look at the Ignition switch. While I don't think it will be the problem, you never know.   

And as Ron said, just because it is new does not mean it is working right.

Good luck and looking forward to hearing the engine run on the next video!

Cuda Ken

[69hemidaytona]

If your voltage is dropping all the way down to 8 volts you have more than a problem with the alternator failing to charge or the voltage regulator malfunctioning. Even if the alternator or regulator completely stopped functioning you would still have 12 volts coming from the battery. It sounds like there is a large draw of current that occurs suddenly. Where are you measuring the voltage when you get the 8 volt reading? I would first have the battery tested to be sure it is good, although I doubt that is the problem. Then I would measure the voltage at the battery terminals after the engine starts and until it dies. If the voltage at the battery drops all of the way to 8 volts you have a massive current draw like a short circuit. If the voltage at the battery doesn't drop when the engine stalls then repeat the same steps at various locations between the battery and the location you are now seeing an 8 volt reading at. Also it is VERY important that you keep the battery disconnected whenever you are not working on this problem. If you do have a short of that magnitude it could cause a fire very easily.

[six-tee-nine]

true, even when your alternator belt is off you still hold your battery tension.

However a voltage drop from 12 to 8 volts from a current draw seems unlikely. Only thing that draws so much power is the starter motor.
If you draw that much current while the engine is running you should blow a fuse or even if there is no fuse you should see smoke from burnt wires.

On the other hand if you want certainty, go step by step from the beginning.
You say you have a new battery, ok then have the alt checked by a repair shop. If it turns out ok then you know what you have and then focus on the ignition parts.

[Dino]

I think it's time to try a new ignition system here. 

[69dodge383]

Ok. Here is what I am going to do.

i am going to cap off whatever wires from the cars orig ignition system that are exposed. next wire the msd 12v hot and the 12v hot for the fuel pump relay to a toggle switch that is wired for power from the battery. so now the fuel and fire power does not run through the orig electric on the firewall. the toggle switch i am going to use is 20amp and should be fine for the signals needed for fuel and fire. i know the alternator is charging the battery correctly so i am pretty sure i will not lose any signal this way. i am pretty much going to bypass the orig dodge ignition. i guess more like a race car switch. i will need the key to work the lights for the car and of course for the starter relay to activate.

doing this will tell me i think what the issue is because i have taken the cars ignition and power source out of the equation.

then make a video and post for you guys to take a look at

question: is the stalling any chance a sign of the motor being cold? i hadnt thought about it because the start ups are and initial idle is so strong. Todays tests are going to be done in my unheated insulated garage. outside temp now is 27 with a high of 38.

[69dodge383]

PS...the DEMON 850 looks much more BEAST than the edelbrock 800  

[firefighter3931]

Keep in mind..it didnt like taper off.  It just cut off the volts and the motor died. The car starts right back up when it dies like this. Same symptom. Even with the old voltage reg that was allowing an 18v chg

A quick drop in voltage is not related to the charging system.....something is going on with the wiring or the battery is defective.  

If your voltage is dropping all the way down to 8 volts you have more than a problem with the alternator failing to charge or the voltage regulator malfunctioning. Even if the alternator or regulator completely stopped functioning you would still have 12 volts coming from the battery. It sounds like there is a large draw of current that occurs suddenly. Where are you measuring the voltage when you get the 8 volt reading? I would first have the battery tested to be sure it is good, although I doubt that is the problem. Then I would measure the voltage at the battery terminals after the engine starts and until it dies. If the voltage at the battery drops all of the way to 8 volts you have a massive current draw like a short circuit. If the voltage at the battery doesn't drop when the engine stalls then repeat the same steps at various locations between the battery and the location you are now seeing an 8 volt reading at. Also it is VERY important that you keep the battery disconnected whenever you are not working on this problem. If you do have a short of that magnitude it could cause a fire very easily.

Sounds reasonable....a large draw or dead short somewhere.  



Ron

[69dodge383]

I just took a quick look at my car and noticed the old oil pressure sending unit wire was bare on end and laying on the oil valley pan under the intake. i forgot to cap it. that may be my issue. also, when i did the test my tester was on the cars 12v source. when i test again today i will check at the alt output.

can anyone way in on my idea above to cap what wires i see and bypass cars ignition by making my own switch? i thought of doing the same for my gauges.

[69dodge383]

I just went out to start the car for todays testing and it wont start. it just acts like it wants to turn over and then starter just clicks. i also notice the dome light dims when i try to engage the starter. the battery is show 12.4v. the battery was new in august.

as a test i have an old ford explorer with no battery. took the battery from the charger and put it in the old ford and it started right up without issue.

this was happening before and i thought i fixed it with a new battery. I also checked my battery ground and engine ground again and both show power.

what would cause this? the battery started another car without issue..

Doug

[nvrbdn]

it is your power travel, not the power source. a coroded battery cable could cause too much resistance.   bad connections, relays, something somewhere is taking away from your current flow you need.

   but i have to add that acording to the size and compression of the engine in the explorer, that engine would need less to turn it over.

[Charger4404spd]

As stated above, if all connections are good you have a bad starter.

[69dodge383]

The starter is good and like two weeks old. this is the same problem i have been having. i am sure it is all electrical now. i am going to be checking through some things tonight.

[69dodge383]

I still dont get this. Checked over all the wires, still not getting why it wont crank. acts like it is going to start and then just acts like it dont have enough power to turn over. i dont get it.

I checked and I have power to the starter relay. Like I said, car tries to start but wont. Loss of power somewhere. I used some 220 sandpaper on my battery terminals also to see if that was an issue. Got the same result. I will prob put on a new set of terminals tomorrow.

I am pretty sure this isnt the starter. I put a tester on the battery and when the key is turned on for the starter to engage the battery volts drop to 9.8v tries to turn over and stops.

I put on a new starter relay when i replaced the starter a few weeks back.


Keep in mind this motor was struggling to turn over, put in a new starter, new battery, new starter relay and then problem went away, was testing car for other electrical issue, went to test today an starter will not engage motor, acts like it dont have enough power

I even tried to jump the starter at the relay and it did the same thing, not enough power.

if the starter got more power to it i know it would start the motor.

[cudaken]

Dam Doug, I feel bad for you! I had less problem with my 68 Road Runner that sat for 8 years getting her started!

Far as getting her cranked over you could try retarding the distributor. Could have it advanced it self? I don't know a lot about the MSD ones. I do have a factory style single point I be happy to send you.

At this point, I think it is time to find a electrical shop. Or just take everything off and start over with stock parts!

Cuda Ken     

[green69rt]

Try swapping the battery with another car??

[nvrbdn]

he put this battery in his explorer and no problem there. if everything is disconnected. everything except the power to the coil and the starter. fully charged battery. no charging system, no wiring harness. just power to the coil and the starter. will it start and run for more than a minute?

[69dodge383]

I found it!!!

Loose ground wire on passenger cyl head. It was tight on the firewall and it was loose where it bolted to the head. i torqued the bolt down and there is no shortage of power. I hooked up the msd again and fuel pump and car fired right up..

I am going to see now if I can get it to idle and all. I def think this was the issue. And I would say the sudden drop in power i saw the other night was the ground wire coming loose.

[Dino]

We're keeping our fingers crossed hoping that was the issue!   

[Back N Black]

To verify the ground system, its really easy. And should be done on every car when you suspect something is wrong.

Start the engine, turn on the headlights.
Set digital volt meter to 20 volt DC scale..

1.  Test between the positive and negative battery post, 14.1 to 14.8 volts is expected.

2.  Test between the negative battery post and the engine block,   0.04 volts is expected.

3.  Test between the negative battery post and the body, 0.02 volts is expected.

4.  Test between the engine block and the body, 0.02 volts is expected.

If you get 0.00 volts on tests 2, 3, 4. Reset meter to 2 volt DC and retest. On test one you should get 14.1 volts if not something is wrong.
On tests 2, 3, 4. If you get more than 0.04 or 0.02 volts you have a grounding problem between those parts.