When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My 72 Cutlass with the original 2bbl 350 recently had a tuneup. The tuneup did wonders and it had only been ~2k miles/20 months since the last tuneup. Seems not that long but, what do I know. My mechanic (different from first guy who tuned it) said that the ignition components were basically fried and so he replaced all the tuneup related items.
A few weeks and maybe a 100 miles later, the car has gone from starting right up with the key turning to starting right up and then cutting off pretty quick. Then, following attempt to start just cranks and cranks. Sometimes, I can eventually get the car to start by keeping the gas pedal down. If that doesn't work, I use starting fluid (ether) and it will start pretty rough and then eventually run smooth.
Adding to and possibly unrelated, I changed the oil to 20W50 from what I believe was 5W20. Thing happening there is there's a bit of oil burn at startup that goes away. Noticeable though.
Anybody have an idea where to go from here? Any suggestions?
What was the quality of the replacement tune-up parts? If its stock I am a proponent of replacing with US made OEM parts. You might have to look for NOS items and not use cheap Chinese crap.
A small amount of oil smoke at start up may indicate worn out valve guide seals, not a good reason to change oil viscosity. The issue you are having does not sound to me to be ignition related. On a carbureted motor such as yours, keeping the gas pedal floored when starting opens the choke slightly to allow more air in. The use of starting fluid followed by rough running initially also indicates to me a fuel issue, possibly dirt in the fuel line or carburetor. When you had the tune up done, was any work done on the fuel system or carburetor; possibly replacing a fuel filter which may have dislodged some dirt in the fuel line? From what you have indicated, I would start with rebuilding the carburetor.
So, the first tuneup was a mix of stuff. AC Delco Capacitor, Points, Cap, Rotor, Autolite spark plugs, the wires were Denso 6718069. Should be noted that my mechanic thinks the capacitor in there was not the right one. Think it was D106P. Believe he replaced with D116
This tuneup was all AC Delco and I think the wires were Duralast Gold from Autozone. Also should be noted, the Coil was replaced this time and not last tuneup.
Last edited by SanTan Devil; December 30th, 2020 at 08:05 AM.
When you had the tune up done, was any work done on the fuel system or carburetor; possibly replacing a fuel filter which may have dislodged some dirt in the fuel line? From what you have indicated, I would start with rebuilding the carburetor.
I should have noted the fuel filter. I replaced the fuel filter before the tuneup and again since. I think you may be onto something tho. It was rebuilt two years ago and hardly very many miles before the tuneup about 20 months ago. New fuel tank and pump at the time as well. Perhaps the original fuel lines are the issue with sourcing the dirt?
It's possible the choke needs to be adjusted. Did the temperature change much between when the tune up was done and when the engine became hard to start?
Keep in mind that big 'ol hunk of iron under the hood will be cooler than the air temp. It would take hours for the engine to reach the same temp as the ambient air.
If you still have the original rubber fuel lines on the car I would recommend replacing them all with fresh. Their age and the use of ethanol mix in todays fuel would contribute to deterioration. Also a good time to inspect the steel fuel line much as possible. Depending on where the car has been, may be evidence of corrosion. I know from living in Cleveland, Ohio for many years that the road salt would rust those fuel lines to the point of leakage.
If its stock I am a proponent of replacing with US made OEM parts. You might have to look for NOS items and not use cheap Chinese crap.
Everyone wants US-made parts, but it's pretty much impossible to drive any car these days, new or old, without at least some parts made in China. NOS is nice, but it's not always readily available nor cheap if you can find it.
Originally Posted by SanTan Devil
So, the first tuneup was a mix of stuff. AC Delco Capacitor, Points, Cap, Rotor, Autolite spark plugs
This tuneup was all AC Delco and I think the wires were Duralast Gold from Autozone.
If you have the boxes for any of these, take a look at them. I wouldn't be surprised to find that at least half are made in China and the other half in other parts of the world. The replacement auto parts industry is world-wide and has been for decades. Parts, regardless of brand, could be made anywhere.
Less than a month ago I bought a new set of AC Delco spark plugs for my '78 Toronado. Below is scan of a portion of the box. Guess where they were made?
Here's an Autolite spark plug box. Designed in USA but made in Mexico. That's a little closer to home.
Last edited by jaunty75; December 30th, 2020 at 11:04 AM.
Jaunty75 I hear you not a fan of new AC plugs or Autolite but have found US made AC for reasonable price or Japanese NGK works well. I have done 2 tune ups on friends cars with Autolite and out of 8 plugs had 3 bad plugs out of the gate. As soon as vehicle warmed up plugs showed an open and no spark. Threw check engine lamp and misfires. It's getting hard to find good parts anymore.
Jaunty75 I hear you not a fan of new AC plugs or Autolite but have found US made AC for reasonable price or Japanese NGK works well. I have done 2 tune ups on friends cars with Autolite and out of 8 plugs had 3 bad plugs out of the gate. As soon as vehicle warmed up plugs showed an open and no spark. Threw check engine lamp and misfires. It's getting hard to find good parts anymore.
I used to find more dead plugs with Champion than with Autolite.
Jaunty75 I hear you not a fan of new AC plugs or Autolite
I didn't say I didn't like them. They work just fine. I was just pointing out that you can't assume that ANY particular brand of auto part, including some of the most storied brands in automotive history, isn't now made in China.
I mentioned my '78 Toronado earlier. When I was doing brake work on it a couple of years ago, I found that every part I bought, Raybestos, Wagner, you name it, were all made in China.
Many people on this site disparage Chinese-made parts ("Chinesium"), and I can sympathize. But I also have news for you. If you want to be able to drive your '69 Cutlass in 2020, one way or another, you're going to end up installing some Chinesium in it, even if it's just a PCV valve. It cannot be avoided.
And I laugh out loud when I read someone stating they won't put anything made in China on their car, or, even more laughable, that they're going to put only U.S.-made parts on their car. That ship sailed decades ago, and, if you adopt that attitude, your car will do a lot of sitting in the garage undriveable.
Last edited by jaunty75; December 30th, 2020 at 02:30 PM.
Have you looked at the points yet, are they burnt? Do you listen to the radio with the key on ever and engine not running, if so your points could have gone up in smoke if they were closed when or if the key was left on. Sometimes a fuel pump will allow gas to drain back from the carb if the valves in it are starting to go bad but car will run fine or sorta fine at or above a idle. Just a few things I would check before swapping out a bunch of parts..... Tedd
When I started reading this post i thought I knew exactly what your problem could be, but then I read on. I have a 1980 wagoneer that had the exact same problems, so I rebuilt the carb, changed spark plug wires, replaced the entire distributor. Check the timing at all kinds of different rpms with the vacuum advanced on or off depending on the chart I was referencing. In the end...it was a bad ignition coil...
Its always the simplest things 98% of the time. Check to make sure the mechanic put your spark plug wires on the correct plugs and didn’t swap a couple. Also make sure your spark plug wires are secure on each plug and post.
At night with your car in the garage (and the garage door open obviously), start the car and kill the lights, look for any wires that maybe arcing intermittently. Try and twist the distributor with your hand, did the mechanic tighten that down properly? Maybe your timing is constantly changing.
the last obviously thing that comes to mind is a vacuum leak. Start the car, and while it’s idling use water from a spray bottle to go around and spray on all the vacuum lines And connections. While spraying a specific spot if the engine Boggs down or dies, you’ve found your leak.
Last edited by Ihatefiberglass; December 31st, 2020 at 07:29 AM.
Well, you have one of the winning replies, I have looked at many of the possibilities listed by the great folks responding and it came down to something very simple- the fuel inlet to the carb was clogged with a piece of thread sealant tape. I have since cleaned the carb and inlet out.
Yes, I know, thread sealant should not be used on a fuel line but... my former mechanic (not my current one) started that trend and, if I now install the fuel line without, it tends to drip a lot of fuel. I have the yellow tape now and also bought some permatex permashield however I’m hesitant to use that.
So, turning this thread to the fuel line issue. I have thought of some longer term solutions to what might be a stripped thread. I could:
install a new fuel inlet
and/or install a new fuel line from pump to carb
These would be affordable fixes however, I kinda want to wait til there’s an issue again bc I’m just so happy the car is back to purring.
Another issue I uncovered is that my 25 mos old battery seemed darn near dead. It was barely cranking, For all I know, it wasn’t the battery and there’s something else awry like a parasitic draw on the battery. the retailer who sold me the battery inspected and gave me a new one. I wanted a cooler battery like an Optima but, if it’s free, I hope this new one lasts another two or three years. I have thought of installing a battery disconnect on the negative post to ward off a possible parasitic draw. I’ve also stopped using my trickle charger bc I have a suspicion it is no longer working,
Is the leak at the flare nut into the fuel filter fitting or the fitting into the air horn? It's unlikely that the former is stripped, but it's pretty easy to strip the treads at the pot metal carb body. Also, look closely at the flare sealing surface on the hard line - does it appear cracked or scratched? One trick I've found when reconnecting that line is to loosen the flare nut at the pump, start the flare nut at the carb, snug both, then tighten.
Which end of the fuel filter housing was the leak on?
There's a fiber or nylon gasket that goes on the carb end that often gets left out. That's also why a lot of carb fuel inlets get stripped threads, because it leaks and people keep tightening it trying to stop the leak. Then the threads strip out of the potmetal and you have a junk carburetor that requires a machinist to repair.
The fuel line end is a double flare fitting and should never require thread sealant to stop a leak.
Once you get that leak stopped, go buy a 3/8" inline fuel filter and install it in the fuel pump suction line on the tank side of the fuel pump. This catches any crud from fuel tank and lines so you don't have to disturb the carb inlet filter housing again.
Pipe dope is much better than Teflon tape for these things.
No sealer of any kind should be used on inverted flare fittings, period. If the flare isn't sealing as designed, no amount of teflon on the threads will seal between the flare nut and the tube.
The leak is at the flare nut into the fuel filter fitting.
And, to answer the second post, I have a new rubberized aluminum gasket. No leak from there. I bought spares of those.
Read that trick that Joe suggested on also loosing the line nut on the fuel pump. That will allow you to get it seated pretty easily and then tighten both nuts. That was exactly how I had to resolve a leak. You do not need to tighten the crap out of the nuts
I am not a fan of the filters with the check valve as it is restrictive and counterproductive from a performance perspective. I have heard too many issues about fuel starvation at upper RPM that was alleviated by removing the check valve. My preference is to eliminate that filter completely and use a larger, free flowing inline filter near the fuel pump.
I like these as they have large filter surface area and a clear housing so the filter element can be easily inspected.
Last edited by Fun71; January 31st, 2021 at 03:09 PM.
December 30th, 2020, 06:47 AM
