74 Cutlass Supreme Started running poorly
#1
74 Cutlass Supreme Started running poorly
Hi everyone, I have an issue that has baffled me beyond belief. My son has been driving my Cutlass for the past 4 yrs. When I first got it 4 yrs. ago, it barely ran. I rebuilt the Quadrajet and replaced all plugs, wires, distr. cap, etc... and it has run fine ever since. NOW... about a month ago, it started dying at stop signs, red light, etc... After fiddling with it for about week and it getting worse, I did the following things: 1. Rebuilt the carb - not much help, 2. Replaced vacuum lines - not much help, 3. drained gas tank and refilled with high octane and seafoam added, helped but no cure, 4. Replaced plugs, wires, fuel filter - not much help, 5. Replaced coil, seemed to help but not a cure, 6. Replaced fuel pump, 7. installed new Summit 4BBL Carb, seemed to help and the more I drove it, the better it got. Ran the tank and filled up again and within 20 miles, yesterday it started acting up again. I wasn't sure Id make it home. Symptoms: Idles smooth but has hick-ups and will die... acts like it isn't getting fuel but once you get moving and hold speed at about 30-40, it seems ok and will suddenly act like it's going to just shut off, at the same time this is happening, Im seeing my tack needle jump all over the place, even while running, the needle will drop to ZERO and then bounce back up to running RPMs, settle down and be fine, and then start to jump all over again.
FYI... it has 50,800 original miles.
Ive been told that the points-condenser may be bad. Can this go "in and out" like that? I am completely stumped here and any suggestions would be greatly appreciated. Mark
FYI... it has 50,800 original miles.
Ive been told that the points-condenser may be bad. Can this go "in and out" like that? I am completely stumped here and any suggestions would be greatly appreciated. Mark
Last edited by Markwz11; June 22nd, 2017 at 07:37 AM. Reason: adding a note for clarity.
#2
Yes your points and condenser can cause issues your describing. Hook a tach/ dwell and timing light up and see what your current settings are. The spark plugs you installed should have been gapped to .040. Dwell should be 30 and timing should be 12* @ 1100 rpm with vacuum advance disconnected. Curb idle should be set to 650 rpm with car in drive. If there is a big variation in these settings the engine won't run correctly. Inspect your points, if they are burnt and/or pitted they need to be replaced. I also replace the cap and rotor at this time.
#3
Thanks Eric. Just to be clear, after all of the above mentioned repairs, I was convinced that the new carb and fuel pump had solved the issue. After new cap, rotor, wires, plugs (properly gapped) the problem still seemed to occur. Once the Summit Carb and replacement fuel pump were put on, it seemed to run (responsiveness) better than it ever had, since Ive owned it. I actually started driving it around town without worry... until yesterday. The problem came right back with a vengeance! The only thing I did not replace was the points and condenser. BUT, it went for almost half a tank of fuel before it started acting up again. Im SO BAFFLED!
#4
So it sounds as if the points have been in there for at least the last 4 years while your son has been driving the car, and I'm guessing they haven't been checked / adjusted during that time. I'm kinda amazed that you replaced all of those parts yet didn't even look at the points.
#5
This car is a '74 - Does it HAVE a set of points and condenser?
I would expect it to be HEI.
Either way, it sounds electrical to me. Whichever type, check the little wires inside the distributor, to the points plate (should have a braided ground wire) or to the pickup.
If it's a points unit, then, hell yeah, by all means set the dwell and then the timing, and have a replacement set of points and a condenser on hand in case yours are bad or that doesn't do the trick.
Also, check the vacuum advance to be sure that it is intact and working.
- Eric
I would expect it to be HEI.
Either way, it sounds electrical to me. Whichever type, check the little wires inside the distributor, to the points plate (should have a braided ground wire) or to the pickup.
If it's a points unit, then, hell yeah, by all means set the dwell and then the timing, and have a replacement set of points and a condenser on hand in case yours are bad or that doesn't do the trick.
Also, check the vacuum advance to be sure that it is intact and working.
- Eric
#7
#8
Kenneth, even tho my son has driven the car over the past 4 yrs., he has only put about 12K miles on it. He is a student and stays local around town. The carb has been a problem from the beginning so, I figured it was fuel related, especially since it ran so well after the new carb installation. All of the other tune-up items I installed were simply because I had decided to sell the car and did not want to hand someone a POS, LOL! When originally inspected, the points looked new (installed by the original owner I purchased it from) so, I blew past that. As I said earlier, it was running better than ever for the past week and I was actually considering keeping it, until yesterday when the issue came right back.
Eric, yes it is points... my local O'reilly store does not even show them in their system. I will probably need to call Summit and order them. That seems to be my next step... fingers crossed!! Thanks guys!!
Eric, yes it is points... my local O'reilly store does not even show them in their system. I will probably need to call Summit and order them. That seems to be my next step... fingers crossed!! Thanks guys!!
#11
A buddy had almost the exact problem with his Chevelle BBC. He did all the things you mentioned and then a steely eyed tech discovered that he had some rust holes in the main fuel feed line. Replaced the line and no further problems.
Your issue may also be a fuel vent system not properly venting and creating a negative pressure in the tank.
Your issue may also be a fuel vent system not properly venting and creating a negative pressure in the tank.
#14
Happened to me once when I replaced the cap with a non vented cap.
Your car may have a semi closed vent system and fuel return line which complicates the process and I've never worked on one of those.
#15
12,000 mile without setting replacing, or cleaning the points.
That's the first thing I'd check - a basic tune-up.
But, due to your symptoms, I'd advise checking the wire from the coil to the points and the ground wire to the points plate very carefully.
And, yes, check fuel hoses and for a vacuum in the tank, though I don't think those problems match your symptoms as well.
- Eric
That's the first thing I'd check - a basic tune-up.
But, due to your symptoms, I'd advise checking the wire from the coil to the points and the ground wire to the points plate very carefully.
And, yes, check fuel hoses and for a vacuum in the tank, though I don't think those problems match your symptoms as well.
- Eric
#16
When your checking your rubber fuel lines if they are hard replace them or if they are really soft replace them. This fuel we get now with the ethanol can turn some fuel lines to gel and can cause all kinds of problems. I replace all of the old type lines with the ethanol resistant, they are pricey but worth it.
Just another thought if your electrical system issues have been replaced and check good.
Good luck let us know what you find.
Just another thought if your electrical system issues have been replaced and check good.
Good luck let us know what you find.
#17
OK everyone... sorry for the "radio silence" but Ive been going thru everyone's suggestions and of course WORK. So Ive checked everything all of you have suggested and although the I agree that the points should be replaced, I think it should at least start. At one point on Thursday, I assumed that I had simply flooded the car, and walked away for the weekend. It ran great on Wednesday morning, started to miss-fire and die, then would start up and run (poorly) until I got home. Now it simply turns over as if ti is not getting spark AT ALL. I checked the distributor at the #1 Cylinder at TDC and the rotor was correct. Its getting fuel and there are no vacuum leaks. So I decided to check that it was getting spark... I could not see any spark from the #1 plug wire. So I moved onto the coil and tried to get a spark from the coil... no spark, but it has juice to the ignition and starter.
Can anyone guide me to where I may be losing fire to the coil? Is there something as simple as a fuse somewhere that I don't know about? Im at a loss!!
Can anyone guide me to where I may be losing fire to the coil? Is there something as simple as a fuse somewhere that I don't know about? Im at a loss!!
#22
I have no way of checking the dwell but with the cap off and rotating the crank, you can see the points open, so they are not staying closed. As far as timing, also with the #1 cylinder at TDC, the rotor is pointing at #1 wire and the timing mark is at about 12. Again I would think that with these specs, it was at least close enough to start up. While turning the engine over with the key, and holding a metal rod directly from the coil wire to the engine block, I am getting no spark from the coil.
#23
Pull the coil wire out of the center of the distributor cap and hold it close to ground with an insulated pliers. Connect a jumper wire to the negative coil terminal and with the key on short the other end of the jumper wire to ground. You should get a spark at the end of the coil wire.
Did you gap the points to .016? To be honest if your going to run points you need a dwell meter. A timing light is a necessity for working on these engines as what your doing is not very accurate.
Did you gap the points to .016? To be honest if your going to run points you need a dwell meter. A timing light is a necessity for working on these engines as what your doing is not very accurate.
#24
This is a good read:
https://classicoldsmobile.com/forums...-ignition.html
https://classicoldsmobile.com/forums...-ignition.html
#25
OK Eric, I just did the test and got a spark.
Honestly, I don't even know how to use a dwell meter and if I was panning on keeping the car, I would change it over to electronic ignition. I do have a timing light tho and when I set the timing last summer (aprox. 3K miles ago) it was running just fine.
Honestly, I don't even know how to use a dwell meter and if I was panning on keeping the car, I would change it over to electronic ignition. I do have a timing light tho and when I set the timing last summer (aprox. 3K miles ago) it was running just fine.
#26
as far as point gapping, Im terrible at that. I know my faults and that's why Ive not attempted it. At this point, I just want to get it running so I can drive it the shop and have all of that done correctly.
#27
Ok if you have spark then your problem could be the black wire on the coil negative terminal to the points is open, the ground wire inside the distributor to the advance plate is broken, bad points or adjusted wrong, or condenser.
#28
#29
I can get a new set of points and condenser from my local O'Reilly store. If I put them in and get them adjusted to anywhere close to .016, would you think that would at least get it running enough to hobble over to my local shop? While I have them out, I can check the ground wire for breaks or better yet, just replace it.
Also, thanks for the Ignition Read... I will check it out for sure!
Also, thanks for the Ignition Read... I will check it out for sure!
#31
Thanks Eric, you've been a wealth of information as always!
I have a quick question for you... my neighbor kid next door came over and gave me a Remote Button Starter because he could not stay and help me. I assumed that I would just hook it up to my wheel-well starter solenoid and battery... but there is no starter solenoid on the wheel-well (like my old Super Bee... sorry but that's my only reference to classic muscle cars) and when I looked under the car, the stater connections were not like any Ive seen before.
I have a quick question for you... my neighbor kid next door came over and gave me a Remote Button Starter because he could not stay and help me. I assumed that I would just hook it up to my wheel-well starter solenoid and battery... but there is no starter solenoid on the wheel-well (like my old Super Bee... sorry but that's my only reference to classic muscle cars) and when I looked under the car, the stater connections were not like any Ive seen before.
#34
Yes, your points are toast... Install the new ones so the rubbing block is on one of the high corners of the distributor cam. Adjust with an Allan wrench to to set your gap so that the feeler gauge slips through flat with minimal resistance and does not force the points to open wider.
#36
Well, I actually jumped on my bike, went and got the points and condenser, got home and got them installed. Gapping those suckers was a real pain but, I was able to get it, at least (in my opinion) close enough to get it started... and NO GO! No difference at all. I think Im done for the day. I don't even know what to try next.
#37
What you need to do now is the same test as before except without the jumper wire, Get the engine in a position to where the points are closed, turn the key on and open and close them gently with a screw driver to see if you have spark.
#39
Just a after thought, when you get that thing running be sure to tell your boy to not listen to the radio with the key on run when the engine is not running. Those points look more toaster than what happens when getting old and just driving. I know it sounds strange but back in the day we commonly changed points at 10-15 thousand miles and plugs at 20 thousand..... Tedd
#40
Thanks Tedd, I honestly have not seen a set of points since my '69 Super Bee back in my junior yr. in 1976 and I could not believe how burned up the points were out of the Cutlass. I will pass-on (to my son) your radio tip. Thanks
Last edited by Markwz11; June 27th, 2017 at 05:03 AM.