Searching for My Dad's 1979 Chevy Suburban

[squaredeal91]

How I find TDC compression is I remove #1 spark plug, stuff a rag in the hole tightly as to make a seal. I even pack it with a screwdriver or something without getting the rag inside too much inside combustion chamber. I bump it over with the starter until I hear the rag pop out, it should be audible if done right. Then move balancer to line up with timing mark.
Sometimes it's difficult to re-stab distributor and get rotor lined up. You can use a large slotted screwdriver if it's long enough to turn oil pump so distributor stabs where you want.

 

[TheHoundsman]

How I find TDC compression is I remove #1 spark plug, stuff a rag in the hole tightly as to make a seal. I even pack it with a screwdriver or something without getting the rag inside too much inside combustion chamber. I bump it over with the starter until I hear the rag pop out, it should be audible if done right. Then move balancer to line up with timing mark.
Sometimes it's difficult to re-stab distributor and get rotor lined up. You can use a large slotted screwdriver if it's long enough to turn oil pump so distributor stabs where you want.

Thanks I will dig into that and start to put a plan together on how to exicute. But grealty appriciate the roadmap.

 

[Grit dog]

Does it die like you turned the key off and run fine the rest of the time (except for the one big backfire)?
If so that suggests an electrical short somewhere on the ignition side that is killing the spark.
Gotta do some real time diagnosis.
When it dies, see if it’s getting spark.
Takes 2 people unless you can pull a wire and pop in a spare spark plug and ground it somewhere visible while cranking.
Could be the actual ignition switch, a wire shorting out (although I feel that would be more intermittent) or anything not replaced with the distributor.

 

[TheHoundsman]

Does it die like you turned the key off and run fine the rest of the time (except for the one big backfire)?
If so that suggests an electrical short somewhere on the ignition side that is killing the spark.
Gotta do some real time diagnosis.
When it dies, see if it’s getting spark.
Takes 2 people unless you can pull a wire and pop in a spare spark plug and ground it somewhere visible while cranking.
Could be the actual ignition switch, a wire shorting out (although I feel that would be more intermittent) or anything not replaced with the distributor.

I have ordered a new ignition switch and a complete distributor. I will work on replacing both next week. I think I have figured out how to replace the distributor but I am a little nervous about getting the timing correct when I do. Fingers crossed. I’ll keep you all updated.

 

[Grit dog]

I have ordered a new ignition switch and a complete distributor. I will work on replacing both next week. I think I have figured out how to replace the distributor but I am a little nervous about getting the timing correct when I do. Fingers crossed. I’ll keep you all updated.

Getting it on the right cylinder firing is easy. Don’t even need to go to tdc if you don’t want to. Getting timing right can be accomplished without actually retiming IF you mark the distributior position very carefully and have a reference for the same mark applied to the new one. You could get it within a degree or 2 in my (really past like 30 years ago) experience. I’ve had the pleasure of not having to do any ignition work to any of my old trucks/jeep. (I did put new points on the jeep years ago. Used grampas match book “gauge” to set them lol.)
That said, have you not replaced all the electrical parts on the distributor already? Your symptoms don’t sound like a worn distributor gear ir bushing or advance weights n springs. Icbw.
Sometimes throwing the whole grocery cart of parts at something is the easiest solution. And more justifiable if you’re replacing 50 year old replacement parts and your time holds significant value compared to the $ spent.
It is good practice though, if you’re diagnosing by replacement method, to only perform one significant thing at a time and then re -test. Helps with future reference you can know what part actually was the problem.
To add to it, 30-35 years ago when I was fixing cars for a paycheck or out of necessity, I don’t recall “new defective parts” being part of the equation. Whereas in the last several years with working on some old, newer and newish personal vehicles, (with 2 kids driving or being driven high miles for years before and through high school I opted to keep those miles being put on cheap used cars and SUVs) I’ve found several instances of junk new parts out of the box. That really adds to the repair and diagnosis time when you can’t trust new parts sometimes either….

 

[TheHoundsman]

Does it die like you turned the key off and run fine the rest of the time (except for the one big backfire)?
If so that suggests an electrical short somewhere on the ignition side that is killing the spark.
Gotta do some real time diagnosis.
When it dies, see if it’s getting spark.
Takes 2 people unless you can pull a wire and pop in a spare spark plug and ground it somewhere visible while cranking.
Could be the actual ignition switch, a wire shorting out (although I feel that would be more intermittent) or anything not replaced with the distributor.

I have ordered a new ignition switch and a complete distributor. I will work on replacing both next week. I think I have figured out how to replace the distributor but I am a little nervous about getting the timing correct when I do. Fingers crossed. I’ll keep you all updated

Getting it on the right cylinder firing is easy. Don’t even need to go to tdc if you don’t want to. Getting timing right can be accomplished without actually retiming IF you mark the distributior position very carefully and have a reference for the same mark applied to the new one. You could get it within a degree or 2 in my (really past like 30 years ago) experience. I’ve had the pleasure of not having to do any ignition work to any of my old trucks/jeep. (I did put new points on the jeep years ago. Used grampas match book “gauge” to set them lol.)
That said, have you not replaced all the electrical parts on the distributor already? Your symptoms don’t sound like a worn distributor gear ir bushing or advance weights n springs. Icbw.
Sometimes throwing the whole grocery cart of parts at something is the easiest solution. And more justifiable if you’re replacing 50 year old replacement parts and your time holds significant value compared to the $ spent.
It is good practice though, if you’re diagnosing by replacement method, to only perform one significant thing at a time and then re -test. Helps with future reference you can know what part actually was the problem.
To add to it, 30-35 years ago when I was fixing cars for a paycheck or out of necessity, I don’t recall “new defective parts” being part of the equation. Whereas in the last several years with working on some old, newer and newish personal vehicles, (with 2 kids driving or being driven high miles for years before and through high school I opted to keep those miles being put on cheap used cars and SUVs) I’ve found several instances of junk new parts out of the box. That really adds to the repair and diagnosis time when you can’t trust new parts sometimes either….

i am kind of approaching it from the mindset you just laid out. Even if the part is not the problem so long as it is not “real” expensive it is good experience i.e. $45.00 fuel pump. We will see

 

[edgephoto]

With an old beast like these replacing parts that can fail is a smart move. It is nice to do some diagnosis so at least you know you will solve your problem.

Replacing a distributor is super easy. You do not need to get it to TDC. Do it the old school redneck way, which works great. Take some masking tape and label the wires at the cap. Label them how ever you want so you can get them back on in the correct order. then remove the distributor cap, mark where the rotor is pointing and where the housing is in relation to something. Take some pictures. Then remove the hold down bolt and clamp and wiggle the distributor housing back and forth while pulling up on it. It will come out. Pay attention to where the rotor is when the distributor comes out.

Before taking it out you should clean the gunk from around where the distributor goes into the block so dirt doesn't fall in the engine.

Take the new distributor and remove the cap. Take the gasket and put it on the housing. Make sure the old gasket is not stuck to the block. Put the rotor about where it was when you removed it and put the distributor housing about where it was with the old one. Then insert the distributor, pushing down, it should go right in and your rotor will line up to where it was on the old one. If you have to jiggle the rotor a little as you insert it. If you have it right it should slide right in.

Once installed tighten the hold down for now. Install the cap and wires. The fire her up and set the timing. You have a timing light and you can see the marks? If not before you start doing anything ignition related find your timing marks. You will need to see these with the engine running.

If you do not have a distributor wrench now is the time to buy one. They make setting timing much easier than trying to use a swivel. You will only have one hand unless you have a helper.

 

[TheHoundsman]

I got back last night and had some parts waiting for me, so this morning, I jumped on the old boy to see if I could figure this out. Based on no small part of this group's advice, I ordered a new Vacuum Advance and a new Ignition Switch. I was able to get both replaced and the oil pressure gauge, which was dripping on the back side of the gauge itself. I have it all put back together, and I am happy to report that it starts and runs. I have not taken it out on the road yet. I would be lying if I were to say I am not nervous about getting stuck on the side of the road again!! But I know I need to do it. I think I will start with some small trips around the block and move out from there. I have some pics from my work today that I will post. I am interested in your thoughts on the looks of the original Ignition Switch looked crusty to me, but I don’t know if that could be what caused my problem. I also bought an in-line spark tester, so if it does happen again, I can see if I am getting spark. (I assume I would start with plug one and go from there). As always, thanks for all the help and advice. Pics to come.

 

[TheHoundsman]

Here are some additional Pics of some other random wiring under the dash. I think picture 4 is the left overs from when it had the automatic transmission.

 

[TheHoundsman]

I also discovered damage to the wiring of the Radio Capacitor, which I installed last week. Looks like I pinched the wires when I was putting the distributor cap back on.

 

[TheHoundsman]

I have ordered a new distributor, but it is not here yet. As I mentioned, I had the Vacuum Advance so if todays work seems to have fixed the issue I will just return the Distributor as they are not cheap.

 

[TheHoundsman]

So yeaterday I spent the day replacing the whiper motor in the Olde Boy. When it rains l,ike it is today it would be nice to be able to move the water out of the way! After doing that and cleaning up some of the wiring that runs to the back for the brake lights and the tailgate, I decided to go for another short ride. I took the boy out for a bigger loop, roughly 4 miles with a few traffic lights. We had to do some stop-and-go as well as some 50ish mph stretches. I am still happy to say I didn’t have any additional incidents BUT this is still a very small sample size and I am still super nervous every time I take it out of the driveway. In an effort to be overly cautious I have new plug wires arriving today and plan on replacing them as well. I have no idea the condition of the plugs themselves. I would be intrested in getting the groups thoughts on if it would be a good idea to replace them as well.

 

[legopnuematic]

If you haven’t done plugs yet, or don’t know when they were last changed it wouldn’t be the worst idea to atleast pull them and inspect.

If they look good continue to run them, if they are cruddy, put new ones in, then you’ll know when they were done and have a record. Pay attention to any anomaly’s as that can suggest potential health concerns for the engine.

 

[TheHoundsman]

If you haven’t done plugs yet, or don’t know when they were last changed it wouldn’t be the worst idea to atleast pull them and inspect.

If they look good continue to run them, if they are cruddy, put new ones in, then you’ll know when they were done and have a record. Pay attention to any anomaly’s as that can suggest potential health concerns for the engine.

Thanks. I was trying to post a video of the engine running, but I can’t figure out how to upload anything other than a photo. When I put the distributor back together and was running it without the air filter on, I adjusted the throttle, and it sounded like a brief “sucking” sound just before the engine revved. It might be completely normal; I just don’t have enough experience to know. Does any of that make sense?

 

[legopnuematic]

The forum doesn’t have video hosting capabilities. You’ll need to upload to YouTube or another platform then link/embed the video in your post.

As far as the noise, was there a significant delay from the throttle opening to the rpm’s increasing or?