cruiser
Well-Known Member
It has power brakes. The master cylinder is a new aluminum one from Dr. Diff and works great. The vacuum booster was rebuilt and seems to work perfectly. All vacuum hoses are new.
What's the best way to find a dead cylinder?
- Thread starter cruiser
- Start date
-
cruiser
Well-Known Member
Yes, advance is good and timing is set to 10 degrees before.
Don't discount anything. All this new parts and "professionally rebuilt" stuff means nothing these days. DON'T go thinking " it can't be the problem because it's new".
Seems like you've "eliminated everything " that's been suggested because"it's all new"
Seems like you've "eliminated everything " that's been suggested because"it's all new"
Inertia
Well-Known Member
We're it mine, I'd have a friend jump in, fire it up, put it in low, brakes hard on. - give it a buncha gas, and load it up, heavily.
It should be missing badly, by your description.
Start pulling plug wires, it should be very evident which 1 or 2 cyls are not working.
Could be head gskt affecting 2 cyls.
Plugs should tell something, one should be "different" .
Tight valves is a good bet.
Did you try slowly closing the choke while hot and running to see what it does ?
Did we ever get a video ? Get a video of it while loaded-up !
Good luck
It should be missing badly, by your description.
Start pulling plug wires, it should be very evident which 1 or 2 cyls are not working.
Could be head gskt affecting 2 cyls.
Plugs should tell something, one should be "different" .
Tight valves is a good bet.
Did you try slowly closing the choke while hot and running to see what it does ?
Did we ever get a video ? Get a video of it while loaded-up !
Good luck
Last edited:
Squirter water on the exhaust manifold. If one does not boil off immediately it is dead.
Read Post #73 ^^^
Inertia
Well-Known Member
Thank you
10 - 4
junkyardhero
Well-Known Member
- Joined
- Jan 23, 2005
- Messages
- 2,971
- Reaction score
- 4,657
four pages and a week later... we've got pics of the plugs, at least a dozen suggestions to check the compression and probably twice as many to ground out wires or squirt liquid on runners.
if you haven't popped the valve cover off yet to inspect for damage or something amiss, it's time for compression or a leak down test. you've already got the plugs out. if that comes up inconclusive, i'd back track to electrical: cap, rotor, wires, coil, ecu and then circle back to a vacuum leak.
if you haven't popped the valve cover off yet to inspect for damage or something amiss, it's time for compression or a leak down test. you've already got the plugs out. if that comes up inconclusive, i'd back track to electrical: cap, rotor, wires, coil, ecu and then circle back to a vacuum leak.
junkyardhero
Well-Known Member
- Joined
- Jan 23, 2005
- Messages
- 2,971
- Reaction score
- 4,657
are we looking at the same plugs or did you have a few too many tallies?
Still saying leak down test here. It will tell you health of each cylinder and, if you have a good ear, where the leak is - valves, rings, head gasket. I would first put an inductive timing light on each plug wire to look for consistent spark. I remember looking at my old '66 motor in the dark and it was a spark show. New wires required.
I had a 79 pickup with a/6 and it did something really weird to me one day.
I drove it to work and back, it ran fine.
I went home from work, hit the shower and was headed "out". Get in the truck and crank, crank, crank some more and no fire. I actually burnt out the starter trying to get it to start. Made no sense since it had run just fine about a 1/2 hour before and didn't die, I shut it off.
It started getting dark, I was still trying to start it with the good open, and then I saw a spark off the coil wire to of all places the upper radiator hose. (That's been 30 years ago, maybe it was a heater hose) I got out, moved that wire over 2" and it started right up. I needed a set of wires.
But of all places to ground out I still don't know how it would have been able to ground out to something made of rubber.... But it did
I drove it to work and back, it ran fine.
I went home from work, hit the shower and was headed "out". Get in the truck and crank, crank, crank some more and no fire. I actually burnt out the starter trying to get it to start. Made no sense since it had run just fine about a 1/2 hour before and didn't die, I shut it off.
It started getting dark, I was still trying to start it with the good open, and then I saw a spark off the coil wire to of all places the upper radiator hose. (That's been 30 years ago, maybe it was a heater hose) I got out, moved that wire over 2" and it started right up. I needed a set of wires.
But of all places to ground out I still don't know how it would have been able to ground out to something made of rubber.... But it did
chryslercruiser
Member
In a previous thread Uncle Dan told you the '74 vintage 1945 was a crappy carb that had numerous problems....
Did your professional carb rebuilder know all about how bad those carbs were and did he know how to fix them? Cause gaskets, and a soak in the ultrasonic cleaner won't fix a bad carb. I'm not saying your carb is bad, but I am asking why you had it rebuilt?
This is not intended to sound unkind, but if you don't do the basic diagonstics you can't find the problem..you are making progress with the vacuum gauge.. and a bouncing gauge is telling you something.. A compression test is also useful... but tell us more about the vacuum gauge. It is confirming what you are unhappy about, but we need more information to determine What/why is the issue..
WHY is the vacuum gauge bouncing? Is the next question.. Because there is a variation in the intake manifold that the vacuum gauge is indicating.
Tell us more about how often it bounces? Is it a constant bounce, an occasional bounce. An occasional repeated bounce indicates one cyclinder. A constant bounce is all the cylinders... which brings up the next question:
When was the last time you adjusted the valves?
As for doing an engine swap, I suggest NOT... just sell the car and buy what you want to be driving.. OR get a shop to rebuild slant 6 in the car if necessary..
An engine swap is very involved.. countless things much more difficult than the topic at hand is involved.. YES It is something you can do.. but it is involved, it is expensive, and if the present issue is vexing, just wait until you spend the thousands, and have a car with a brand new engine that vibrates going down the road...
Dale Davies
Well-Known Member
Dirt and/or salt on the hose lets the spark track to metal. Humidity in the air is absorbed by the dirt/salt to allow the electron transfer. Eventually it will burn a carbon track into the rubber. A bit hard to see if you are not looking for it.
In my case as I remember it was a hot dry day. Don't remember exactly, that was a long time ago. Maybe it was humid out? Definitely remember it didn't feel like a "damp" day, definitely wasn't raining.
Right. How many times have you seen me say, "Just cause it's new, doesn't mean it's good" ? LOL
....and that's SO true, unfortunately even moreso today with the influx of crappy imported parts. This is exactly why I recommend hawking ebay for NOS older American made parts, because the quality is there. That's how I shop for ALL my internal engine parts such as rings, bearings and the like.
Check it out at night or in a dark garage with the lights out. A squirt bottle misting the wires with water will help out.
Please do not use carburetor cleaner, or anything flammable to check for vacuum leaks. Think about what you're doing there. Spraying FUEL on an engine powered by FIRE and with high voltage secondary ignition wires. So many ways to cause a fire and burn your car down. I've seen a really nasty engine bay fire cause by it and all we could do was push the car out of the shop and watch it burn because there was no extinguisher and the water hose was not close enough. Water in a spray bottle works just as well and is not dangerous.
You might be surprised how many "good" ignition systems will fail that test and you know why? Most of the time, it's because people absolutely REFUSE to use dielectric grease on plug wire connections. It's usually that simple.
Dale Davies
Well-Known Member
Up here they dump calcium chloride on the roads by the ton. Snow and ice is melted and the spray gets on wood power poles. In the spring it will be OK until we get a foggy day or light drizzle, which gets the built up layer of road salt and dirt damp. The high voltage can them start to track down and catches the poles on fire. A heavier day of rain will wash the salt and dirt off so there will be no problem.
Once it starts to carbon track it does not get better on its own and gets worse even when dry.
Dad bought a 67 Merc in 69 with a 390 2V. Eventually it was not starting well. One evening he had it running on the driveway as it was getting dark out. He noticed the plug wires glowing blue as the spark energy went along the wires. He said it was like they were clear plastic tubes with shots of blue liquid going through. The next day he got a new wire set and installed them. Started on the first couple of revolutions agai .
Dale Davies
Well-Known Member
I worked at a Dodge Chrysler dealer for a short time. Shop foreman came by and saw me putting dielectric grease in the plug boots to help removal in the future. He gave me **** and said it would cause the spark to track to ground. Shop foremen over the years have proven to me to not be the brightest around.
I always like to make life easier for next time. It is like turbo mount nuts that seize on if an antiseize is not used. I always put a dab on the studs. Other guys would ask why and when I explained they would say, "screw the next guy, it won't be me". With that attitude working in shops got too much for me. If every mechanic looked at it like they would be the guy to work on it next time, all our jobs and lives would go easier and less stressful.
how many plug wires have you seen where the boots were on and the wires within werent seated in the cap terminals?
cruiser
Well-Known Member
Not yet, but I think I'm narrowing it down to an exhaust leak and perhaps an exhaust valve problem. My buddy is going to contact me in the next week or so and we'll do a compression and leak down test at his very well equipped garage. Again, thanks everyone for the excellent suggestions. Once I find and correct the problem, I'll publish the results.
-
