Help Needed... Problem with 1972 Chevelle... car won't run
05-04-2010, 10:52 PM
#1
Safety Car
Thread Starter
Help Needed... Problem with 1972 Chevelle... car won't run
Hi guys,
My brother is having an issue with his 1972 Chevelle and he can't seem to solve it. He asked if I could ask my Corvette pals here on the forum so hopefully this is the right place. If anyone has any ideas after reading his words below, please let me know. Thanks in advance!
My brother is having an issue with his 1972 Chevelle and he can't seem to solve it. He asked if I could ask my Corvette pals here on the forum so hopefully this is the right place. If anyone has any ideas after reading his words below, please let me know. Thanks in advance!
Originally Posted by Alaskanpilot's Brother
Hello readers,
I have a problem with my Chevelle and I am running on empty with ideas of what to do. Hopefully I can get some help or ideas from posting. Thanks in advance.
What I have:
1972 Chevelle
350 ci small block chevy
Modified QuadraJet Carb.
Mallory HEI distributor
Mallory Hyfire 6a CDI Igntion Box
Newly installed generic electric fuel pump
Holly fuel regulator.
700R4 trans.
The problem I have:
The car, for a long time, has been running smoothly without issue. But last Friday something happened suddenly. I should note that on this day it was raining and hailing, though just cloudy when I started it up to leave work. I drive maybe 100 feet and it stutters then stalls. I was low on gas so I figured I just neglected to put enough fuel in, gauge said I had a little but I put more in anyway, no change. It cranks just fine, but that is about all it does. If I let the car sit then try again occasionally I would get a single sputter of the motor then nothing.
I looking around for other possible issues and here is what I have done so far. I aired out and dried the distributor, inside the cap and in all the boots. I rebuilt the carburetor. Checked all my electrical connections and tested my ignition box. I wasn't getting any signals out of the box so I replaced it. After replacing the box I got it to sputter a few times and had it running a few seconds. It ran very rough and with low rpm. I gave it a little gas and it back fired then died. I have been able to get it to sputter a few times since but not running and it mostly just cranks.
I am unsure of what this issue could be right now. I could really use any help and insight you may be able to provide, I would be happy to hear anything you have to say or ask.
Thanks a lot for reading.
I have a problem with my Chevelle and I am running on empty with ideas of what to do. Hopefully I can get some help or ideas from posting. Thanks in advance.
What I have:
1972 Chevelle
350 ci small block chevy
Modified QuadraJet Carb.
Mallory HEI distributor
Mallory Hyfire 6a CDI Igntion Box
Newly installed generic electric fuel pump
Holly fuel regulator.
700R4 trans.
The problem I have:
The car, for a long time, has been running smoothly without issue. But last Friday something happened suddenly. I should note that on this day it was raining and hailing, though just cloudy when I started it up to leave work. I drive maybe 100 feet and it stutters then stalls. I was low on gas so I figured I just neglected to put enough fuel in, gauge said I had a little but I put more in anyway, no change. It cranks just fine, but that is about all it does. If I let the car sit then try again occasionally I would get a single sputter of the motor then nothing.
I looking around for other possible issues and here is what I have done so far. I aired out and dried the distributor, inside the cap and in all the boots. I rebuilt the carburetor. Checked all my electrical connections and tested my ignition box. I wasn't getting any signals out of the box so I replaced it. After replacing the box I got it to sputter a few times and had it running a few seconds. It ran very rough and with low rpm. I gave it a little gas and it back fired then died. I have been able to get it to sputter a few times since but not running and it mostly just cranks.
I am unsure of what this issue could be right now. I could really use any help and insight you may be able to provide, I would be happy to hear anything you have to say or ask.
Thanks a lot for reading.
05-04-2010, 11:35 PM
#2
Le Mans Master
Ignition box and distributor are not reading each other. Did he re-test the 2nd box? Is the distributor points or electronic? If electronic, could be the pick up coil.
Stupid question, but did he check for TDC and the rotor position? Could have jumped time and the wet weather was just a coincidence.
Stupid question, but did he check for TDC and the rotor position? Could have jumped time and the wet weather was just a coincidence.
05-04-2010, 11:44 PM
#3
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Hey,
I'm the brother with the car.
The distributor is an HEI, and I was pondering the coil myself but water over the ignition box was main main reason for going to it. Also, when I checked the distributor, all was dry. Not saying that means the coil is good, that was just what my line of thinking has been up to this point. I also bought a new coil just a few months ago, so it is pretty new. Would be a shame for that to be bad.
As for the timing issue, I haven't checked. The reasoning is because when I have had it running, albeit short, it was running smooth enough for me to rule out mistiming. Never had timing issues once with this car, can a distributor jump time like that?
I'm the brother with the car.
The distributor is an HEI, and I was pondering the coil myself but water over the ignition box was main main reason for going to it. Also, when I checked the distributor, all was dry. Not saying that means the coil is good, that was just what my line of thinking has been up to this point. I also bought a new coil just a few months ago, so it is pretty new. Would be a shame for that to be bad.
As for the timing issue, I haven't checked. The reasoning is because when I have had it running, albeit short, it was running smooth enough for me to rule out mistiming. Never had timing issues once with this car, can a distributor jump time like that?
05-05-2010, 11:51 PM
#4
Le Mans Master
Hey,
I'm the brother with the car.
The distributor is an HEI, and I was pondering the coil myself but water over the ignition box was main main reason for going to it. Also, when I checked the distributor, all was dry. Not saying that means the coil is good, that was just what my line of thinking has been up to this point. I also bought a new coil just a few months ago, so it is pretty new. Would be a shame for that to be bad.
As for the timing issue, I haven't checked. The reasoning is because when I have had it running, albeit short, it was running smooth enough for me to rule out mistiming. Never had timing issues once with this car, can a distributor jump time like that?
I'm the brother with the car.
The distributor is an HEI, and I was pondering the coil myself but water over the ignition box was main main reason for going to it. Also, when I checked the distributor, all was dry. Not saying that means the coil is good, that was just what my line of thinking has been up to this point. I also bought a new coil just a few months ago, so it is pretty new. Would be a shame for that to be bad.
As for the timing issue, I haven't checked. The reasoning is because when I have had it running, albeit short, it was running smooth enough for me to rule out mistiming. Never had timing issues once with this car, can a distributor jump time like that?
As for the timing, it can run after it jumps time, but usually will run a little crappy or be hard to start. And a distributor won't jump (unless a gear tooth breaks. What is meant by "jumped timing" is that the timing chain actually jumped a link or two, usually caused by teeth breakage on the timing gears. Again, usually will be hard to start and/or run a little crappy. Simple way to find out is pull a plug, stick your finger in the hole and have someone bump the engine until you feel compression come up and tries to push your finger out of the hole. Remove finger (if not already pushed out from pressure), stick a thin bladed screwdriver in the hole and check to make sure the piston is at TDC. Pull the d-cap and look where the rotor is. Is it directly pointed at the plug wire of the cylinder you checked? Yes, great. No, you have issues.
I would be willing to bet if you pulled that distributor and stuck a spare one in, you would be up and running. Run the test and see what happens.
05-06-2010, 12:04 AM
#5
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Hmm, ok, so that is what you meant by jumped timing, I had a guess. I have worked with some timing issues on other vehicles before, nothing jumped, but enough for me to know hard starting and how to time a car using the trusty finger. But I am not sure it is timing. For one, the car starts real easy, same as always. Starter barely has to work, just nice and fast. Also, the engine is under the 30K mile mark by a good ways and when I built it I used heavy duty double roller timing chains and gears. While I don't know for sure, I imagine those are very hard to break. I hope that isn't it.
I have been tinkering some more and I have two areas that I see as the potential problem. One is the coil. The best I can do is a spark test using my ignition cpu (which it fails) and an Ohm test using a multimeter (which is 50/50). I know the resistance test is far from conclusive, but that is where I am at with that. The second is the coil pick up. I am gonna run my multimeter across that tomorrow when the weather clears.
Thanks for the link, all this is helping a lot.
I have been tinkering some more and I have two areas that I see as the potential problem. One is the coil. The best I can do is a spark test using my ignition cpu (which it fails) and an Ohm test using a multimeter (which is 50/50). I know the resistance test is far from conclusive, but that is where I am at with that. The second is the coil pick up. I am gonna run my multimeter across that tomorrow when the weather clears.
Thanks for the link, all this is helping a lot.
05-06-2010, 12:21 AM
#6
Le Mans Master
Since it starts so easy, you can pretty much rule out timing at this point. A quick TDC test won't hurt though and would confirm.
As I said, coil pick ups in GM HEI are famous for crapping out. You already said it has failed a spark test. Personally being that they are so damn cheap, I would just grab a used one from a boneyard, throw it in and see what happens. Even new (rebuilt) ones are dirt cheap. Accel units can be had for well under $150 which is less than a new HD coil and pick up would cost.
Have you actually checked for spark via the coil wire? (wear heavy insulated gloves or use proper tool)
As I said, coil pick ups in GM HEI are famous for crapping out. You already said it has failed a spark test. Personally being that they are so damn cheap, I would just grab a used one from a boneyard, throw it in and see what happens. Even new (rebuilt) ones are dirt cheap. Accel units can be had for well under $150 which is less than a new HD coil and pick up would cost.
Have you actually checked for spark via the coil wire? (wear heavy insulated gloves or use proper tool)
05-06-2010, 12:33 AM
#7
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Well, where I am, cheap all depends on if I can find it locally or not. No scrap yards I can use around. Oh, and did I mention, my distributor is not GM, it is a Mallory distributor. An 85 Series to be exact. Only a few years old. A new coil would cost me $60 plus shipping to AK. Not sure on the pick up.
But check this out. I have my coil sitting in front of me, on my coffee table. I was ohm testing it. The middle prong, the ground, for this type of distributor is like a thin metal arm that goes into the coil, well onto the bottom of it around one screw hole. Like a thin metal arm about two inches long and has a bend or two, whatever. I am sure you get the idea. Anyway, this arm is just a simple metal piece, but when I pulled it out, I found water spots on it. I didn't check the distributor for water when this first happened, my bad, so if there was water in there it would have dried up. Interesting I think. Relative? Could be. I know coils don't like water.
But check this out. I have my coil sitting in front of me, on my coffee table. I was ohm testing it. The middle prong, the ground, for this type of distributor is like a thin metal arm that goes into the coil, well onto the bottom of it around one screw hole. Like a thin metal arm about two inches long and has a bend or two, whatever. I am sure you get the idea. Anyway, this arm is just a simple metal piece, but when I pulled it out, I found water spots on it. I didn't check the distributor for water when this first happened, my bad, so if there was water in there it would have dried up. Interesting I think. Relative? Could be. I know coils don't like water.
05-06-2010, 09:20 AM
#8
Le Mans Master
Water indication could have shorted it out.
I would do a web search on how to check Mallory parts as I don't know if they are identical to GM HEI tests.
I hear you on the cost and shipping to AK, but I would check out local for an Accel unit and then look at Advance Auto. They always have discount codes (right now it is 15%) and shipping is free. Not sure about shipping to AK.
You could also call Mallory techs and have them tell you how to do proper test.
Good luck.
I would do a web search on how to check Mallory parts as I don't know if they are identical to GM HEI tests.
I hear you on the cost and shipping to AK, but I would check out local for an Accel unit and then look at Advance Auto. They always have discount codes (right now it is 15%) and shipping is free. Not sure about shipping to AK.
You could also call Mallory techs and have them tell you how to do proper test.
Good luck.
05-06-2010, 04:22 PM
#9
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Ok, I just made some good progress on my diagnosis.
I just tested my pickup using the methods taken from the link I received, which also were standards pick test methods. It passed both tests.
I also decided to test all my wires coming into contact with my ignition system. Like say if there were a short in my ignition switch of if the switched power wire had an issue. All these wires are fine and have full power, all is well.
With the pick up, cpu, wires, and plugs all fine, the only option left is the coil. This makes me happy a bit, but I won't know for sure until I get it running. Gotta wait a few days for the new coil to arrive.
Thanks for all the help thus far.
I just tested my pickup using the methods taken from the link I received, which also were standards pick test methods. It passed both tests.
I also decided to test all my wires coming into contact with my ignition system. Like say if there were a short in my ignition switch of if the switched power wire had an issue. All these wires are fine and have full power, all is well.
With the pick up, cpu, wires, and plugs all fine, the only option left is the coil. This makes me happy a bit, but I won't know for sure until I get it running. Gotta wait a few days for the new coil to arrive.
Thanks for all the help thus far.
05-06-2010, 10:32 PM
#11
Race Director
05-06-2010, 11:13 PM
#12
Team Owner
I dont see in the thread that you used basic trouble shooting techniques first.
Did you check for spark to the plugs? Did you check for power and a pulse at the coil? Do you have spark at the end of the coil wire to the distributor? What is the timing, have you checked the base timing yet? Have you checked your ignition switch? Did the distributor move? Do you have fuel pressure? Any huge vacuum leaks?
Did you check for spark to the plugs? Did you check for power and a pulse at the coil? Do you have spark at the end of the coil wire to the distributor? What is the timing, have you checked the base timing yet? Have you checked your ignition switch? Did the distributor move? Do you have fuel pressure? Any huge vacuum leaks?
05-10-2010, 07:05 PM
#14
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Ok, now I am seriously running out of ideas and going out of my mind.
I installed the new coil, and things are better, but I feel I have still missed the main problem. I can now get it to start, or attempt to start, regularly, but it won't stay running. As soon as I left of the start the engine dies. It can't keep itself going, or something.
I am gonna do new spark tests and recheck the timing soon. Fuel pressure is fine. I have a new electric pump and it is still functioning properly.
If I can't find anything after this I think I may have to just give up and take it to a pro. Though I know this is a simple fix, I just can't figure where.
I installed the new coil, and things are better, but I feel I have still missed the main problem. I can now get it to start, or attempt to start, regularly, but it won't stay running. As soon as I left of the start the engine dies. It can't keep itself going, or something.
I am gonna do new spark tests and recheck the timing soon. Fuel pressure is fine. I have a new electric pump and it is still functioning properly.
If I can't find anything after this I think I may have to just give up and take it to a pro. Though I know this is a simple fix, I just can't figure where.
05-11-2010, 10:51 AM
#16
Le Mans Master
05-11-2010, 11:40 AM
#17
Team Owner
Not really, I've seen plenty of older cars have the "run" position go bad. The car starts while cranking and as soon as you let go of the switch and let it return to the run position, it dies.
05-11-2010, 11:58 AM
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Ok, now that is something I didn't think of. Since the car starts the thought of a broken switch never occurred to me. The switch has been stiff lately, though only when the weather is around freezing or below. I wonder. So when you say the switch, do you mean the ignition piece the key goes into or the little box that is on the steering column connected to the key piece? I have never had one go bad so I am not 100% sure on this area.
So if the 'run' position is bad, would I still have regular key on power like I do?
And I am clueless on the ballast issue, I have no idea what you mean. What is that about?
So if the 'run' position is bad, would I still have regular key on power like I do?
And I am clueless on the ballast issue, I have no idea what you mean. What is that about?
05-11-2010, 12:12 PM
#19
Race Director
Not that this is necessarily your issue but I have two cars with mallory Unilite distributors. My Vette had started to where just driving at times it would shut off. Or sometimes it didn't want to start but would try a little then just magically started and ran. I checked the coil, all the wiring, bypassed wires to the ingition with test cables to eliminate the chance of it being related to the wiring. Tried many things. Finally I took the ignition modual out of my camaro's distributor and put in my Vette. Now all is good.
05-11-2010, 12:19 PM
#20
Race Director
On my Vette for the longest time it would not actaully start until you let off of cranking the engine then it would fire. So what I did was wired up a relay that allowed full voltage to go to the coil while while the starter is engaged but once the starter is disengaged the coil is fed power through the resister at the lower voltage. Made it fire right up after that.