Check the compression on 2 cylinders. It it’s below 100 psi you likely need the timing chain replaced. On SBCs the chains usually fail near 200,000 miles but I’ve seen them fail at 150,000 up to 300,000 depending on maintenance and driving conditions.
This one has a bit over 250,000 on her so I’m taking a good guess and calling that its time for a new engine.
I am homeless and I’m talking to a lady that does charitable work and she seems to think if I can purchase a new crate engine I can get it dropped in for free.
My problem is I don’t know what engine to purchase.
Again its a 1991 suburban with a 5.7L 350 and I’m not sure if its a 2 or 4 bolt main 
So I was wondering if someone could donate some time and help point me in the right direction to a new engine that would drop right in?
I would not pull the distributor out if it hasn’t been pulled out already. That looks like a cam position sensor instead of an igniter. It works with the crank position sensor to determine the timing of the spark. IF the timing chain were to have jumped a tooth, realigning the distributor will NOT help. It will only make things worse.
I’m still not clear about why you started this project in the first place. Before you pulled the distributor cap, was the truck running OK? Were you having a problem or were you looking to head off a potential problem?
I’m thinking, without knowing your skill level or familiarity with this vehicle or vehicle brand, that possibly you aren’t getting something right or one of the new parts isn’t right or maybe defective.
I have had new rotors that were simply defective and had to put the old one back in until I got to the parts place and got a replacement. Usually the vehicle just wouldn’t start at all in those cases because the rotor was shorting to the distributor shaft.
Inside the rotor is a keyway that aligns with the distributor shaft. I don’t know if there are different key positions, usually that is not the case but I’d look into the center of both the old and new rotors to make sure the key is in the same position on both. The rotor should be secure in the keyway when installed on the shaft.
Check the distributor caps to insure that the plug towers are in the same place. Look for any cracks in the cap as well. Look inside for any pencil or ink marks. Some inks are conductive. If all else fails, put the old parts back on, with new screws of course and see what happens.
Please let us know how everything works out with getting someone to replace the engine for free.
I don’t think either one of you have any idea just how expensive a crate engine is . Definitely more than a 1991 Suburban is worth. That is not an simple task to remove a replace an engine. I can’t see anyone doing that for free.
I know how much they cost and yes it cost more than what I paid for the vehicle but at the same time its a better option for me than buying another used vehicle that I can afford that will more than likely will break down in six months.
I will be personally purchasing the engine with my money if I do decide to go this way and the only thing being donated is the time to be swapped. I could do it myself in a few days but where I have it parked I can’t be swapping engines.
Somehow being ’ Homeless ’ and having money for a crate engine seems like a contradiction .
Being homeless has nothing to do with it as not every man being homeless is broke lol, I actually live in my suburban and have electricity ran to it and everything else that I am comfortable living with. Its really no different than living out of a van other than size.
If the engine was running smoothly and quietly before this problem and the compression indicates that the timing chain has jumped replacing it would be much cheaper and the engine would likely run with fewer problems than a crate engine that was installed in the driveway. A SBC engine timing chain replacement is about as basic as you can get. And if the chain has lasted 250,000 miles the engine has been well maintained…
So the engine was running pretty good, then you had a dist cap bolt problem that required re-drilling the hold down bolts for the cap, new bolts, installed a new cap and rotor but now it won’t run very well? Is that correct? If you didn’t replace the cap and rotor, that’s the first step. If you can’t replace the cap and rotor, are you able to measure the resistance from the high voltage common input to the rotor to each of the spark plug? That might provide a clue. It’s possible the cap now isn’t at the same height as it was before. The rotor often points slightly before the number one spark plug post at the time the plug fires, if that’s of any help. The “before” direction depends on which way the rotor turns, clockwise or counter-clockwise. Removing and re-installing the distributor won’t solve a mis-pointing rotor btw, it will still be mis-pointing the same as it is now, once you rotate the top of the distributor to adjust the timing to spec. Have you checked the timing w/a timing light on the balancer? If not, that’s probably the second thing to do. Best of luck.
My guess however is some of the spark plugs wires have been damaged during this process, and that’s the actual problem: bad connection between the distributor and the spark plugs.
Spark plug wires don’t affect the rotor position. The fundamental problem is that the rotor does not align with the #1 plug tower when the #1 piston is at TDC. The distributor position had not been touched prior to the observation. So either the timing jumped or the rotor was mechanically jammed with the cap misaligned and caused the dist to rotate as Nevada suggested. Until that issue is corrected, nothing else matters…
I worked on her all night and I actually got her to start and run for a few minutes but I have 3 issues. First #8 plug won’t go in right and when I removed it also gave me trouble. I think whoever had the suburban before me screwed it up because this is the first I have pulled that plug out. #2 when I shut the engine off I notice smoke coming from the throttle body. #3 I pulled plugs and the the are turning black and I just bought these today.
Any clue to what’s causing smoke from the throttle body and why new plugs are going black from a from 5 minutes running?
I want to add something here. If you are turning the engine by hand and the rotor reaches the post before you get to TDC, that is OK. At TDC, the rotor should be a little past the post. The actual spark timing depends on a number of factors including engine load (measured by TPS and intake manifold vacuum) and engine RPM. Typically the spark will occur anywhere from 4 degrees before TDC up to 30 degrees before TDC. The rotor should point directly at the post at around 15 to 20 degrees BTDC to split the difference.
If you are seeing this, then your problem is not the distributor position or timing chain alignment.
Edit: just read your latest post which you posted while I was writing mine. I’m can’t type fast. You only ran the engine a couple of minutes so it was injecting extra fuel. It never warmed up enough to burn those deposits off your plugs.
Your intake manifold would have some residual fuel in it from the extra fuel used when cold. You probably got it just hot enough to vaporize a little of that fuel creating a wisp of grayish/white smoke.
Well if I can only get this damn plug to go in this is really bugging me because it seems as if threads are messed up. It goes in like 3 turns and stops and it keeps going in that same way 
Maybe it’s an ignition timing issue…
You worked on it all night but what exactly did you do?
The timing chain jumped. So a buddy of mine came over with a chain kit and gaskets that he had just laying around his garage and we pulled the cam then he did something that was beyond my knowing at this point I just watched and tried to learn something then I installed the new gears and chain and spent all day today getting everything back on. We never messed with the distributor he said its where it should be.
He didn’t have a timing gun so I’m waiting to make a trip to autozone sometime this week. In the meantime I’m trying to figure out what I should do about this spark plug issue.
Good for you for discovering the cause of the poor engine performance problem OP. I wonder what caused the timing chain to jump coincident w/the distributor cap problem? Maybe just a coincidence. Or could be related to the distributor cap somehow if the distributor gear is driven by the camshaft. Maybe the distributor’s rotation jammed and that affected the camshaft & then the timing chain. But it is interesting to consider what caused it.
You need to figure out if the cylinder head threads are damaged or just gunked up w/carbon.
First determine the thread size and pitch of the spark plug. You may find that by going to a sparkplug manufacturer web site, enter in your spark plug part number and see if it is in the specs. Then go to a hardware store that sells grade 8 bolts. Buy a bolt that size, it must be grade 8 or 12.2 if metric or harder. Put some oil on it and run it down the spark plug hole.
If you can find a bolt with a starter nose, that is a small unthreaded portion at the tip, it will be less likely to try to cross thread.
Some parts stores carry a thread restorer kit. You can borrow these, you have to put a healthy deposit but you get that back when you return it. I usually just use my credit card, when I return the kit, I get the deposit credited back onto my card. If they have the correct size restorer tap, it will have the starter nose on it. Do NOT get a tap and die kit. A tap and die kit is to cut new threads. You want a thread restorer kit which rolls the thread back into place. The restorer will give you stronger threads where a cutting tap will yield weaker threads.
You’ve got a Suburban, but the picture shows a Motorcraft plug . . . 
Yeah I’m pretty throwed off by this myself because when I bought them I watched the guy enter everything on the computer for my vehicle and he said for the money i have i can get these. Then when I got back i was thinkimg wtf is this 
but they do fit and ran the engine. I had to walk several miles to get them and I really didn’t feel like walking back.
Should I take them back and complain they sold me the wrong stuff? I’m not so sure they will take them back now…