She's got the shakes, need help locating the cause.

[HotRodPC]

Sounds like you've got a bad engine miss. Being it gets worse when in gear or under strain I'll assume it's a miss. A bad one. Is it possible your firing order is wrong on the dizzy cap. Needs to be 1 8 4 3 6 5 7 2. How about those leaking header gaskets maybe burning up plug wires? Do you have one of those laser temp thermometers? What you can do is point that to each port of the exhaust manifold with the engine running. In this case, the header tubes. Hit each tube and note the temp. If you find one that's alot cooler than the others, then you know that cylinder isn't firing at all and it's not getting combustion and therefore no hot exhaust leaving the cylinder. That will narrow down which cylinder or cylinders are having the problems. When you can narrow down which cylinder or cylinders are not firing, then you might consider a compression test on those cylinders if all the igntion components seem good. Maybe you've wiped a cam lobe or 2, maybe a rocker stud had pulled out, bent push rod etc. Any backfiring going on in either the intake or the exhaust???

 

[HotRodPC]

Lmfao, after actually reading his post I feel like it’s everything except the head. I think burnt valve and bad rings. I also read that he swapped the plugs and it ran for a day or two. Making me think that originally oily plug is oily again. I’d swap that one out and see if she shapes up @Turt13
You might be doing that every couple days until you rering it. But that truck sounds seriously neglected for a long time to trust as a daily.

If that was the case, some of them screw on non foulers will get him by in a pinch and keep the oil off the plugs, but I not leaning that direction yet.

 

[HotRodPC]

Here's another reason why you want to determine which cylinder or cylinders are missing. This seems to be a hard miss if it's as bad as you say. If it's 2 cylinders right beside each other, then I'd be willing to bet there is no compression on the 2 cylinders. That's indicative of a blown head gasket between cylinders. The compression just escapes to the next cylinder back and forth which means 2 dead cylinders for the price of 1.

 

[Rusty Nail]

The transfer case level checks like a differential. Fill it till it comes out, check it with your pinky. NP 208s are very tough cases but they need fluid.
Open it with a big crescent wrench so you dont gotta get back up.

I was referring to the check valve in the brake booster vacuum hose..if youre gonna start chasing .misfire, I suggest to verify the engine grounds first.

Hope this helps!

Likes reading novels...*with pictures!

 

[gotyourgoat]

Ok, so here's what she is:
81k20 4x4
350 w/ 1406 eldelbrock carb, some off brand or homemade headers, t400, np208 case

Here's what she's doing:
Starts right up, usually. If not, she will with a little throttle.
She's got a rough-ish idle. Can't tell if it's the idle for sure though, motor might just be shaking.
She will drop idle when put into gear, not without a large metallic clank when shifting from park to reverse, bigger clank when going from r-n-d, or d-n-r.
When put into gear, the shake gets worse. When under load, she's at the worst. We have to park on a hill, and to leave for work my lady has to put it in reverse, up the hill, and Vickie (truck) does not like it, at all. once in a while if she's not warm she will try dying.
Other times under load, like trying to speed up, especially on an incline, and at speeds of >45mph, don't know much about higher speeds, she just doesn't want to go and you can feel her 'shaking' all the way through the janky ass seat, floor boards, etc.
When deceleration is occurring, seems to be absent. If you have enough momentum, like before a hill or something, she doesn't do it as bad. She just doesnt have any umph.

Here's what has been done to try and help:
Plug wires were laying all over each other, used zip-ties to make spacers.
Cleaned up plugs I could get to at the time without the right tools, about 4-5/8. They were black and carboned. Couple had a little white with mostly black, and one was oily. They were bad. Can't afford decent new ones, current ones are auto lite cheapos, put in less then 3k miles ago.
Fuel filter- replaced last week, helped for the drive home from the parts store, kinda. It was also really bad, had what looked like sand, and black specs from the hose I'm assuming all over it.
Air filter- was getting pretty dark, replaced 2-3 weeks ago. At this time, iirc, it was after a friend helped adjust the carb, and oil leaks on the covers were being addressed. Vickie would screrch tires with little effort, and we didn't run her hard. Lasted for about a day. Air filter still getting dark from header leak I'm sure
Header gaskets- got one replaced today, the one I took off was blown out every cylinder. Other is planned to be done tomorrow. I believe this was the cause of my new air filter already getting crummy. And as well as the old. Hell, on the other side we have been missing a header bolt for a month or so that I know of.
1 week ago, Tested for vacuum leaks with carb cleaner and gauge, ,found two big holes in the hard line to the vacuum mod. On tyranny. Fixed that, temporary. Cleaned out line, patched it. This is when she started really acting up. Retested for leaks, couldn't determine any leaks anywhere.
Running strictly 91 w/o ethanol. Had sat this winter with 10% ethanol for a bit. Ran some type lucas cleaner through it when changed fuel filter. Have yet to test psi of fuel.
Found brace for t-case to motor was missing bolt on motor, planned to be fixed.
Timming adjusted with vacuum gauge, And rotation of cap. advanced a little and vacuum went to be 14-15 hgs. From 11 hg. Had to up idle speed to up vacuum as well. Adjust carb a bit, believe she's sitting at 15-16, has the ever so slightest flicker in the needle. Can hardly tell. This is at 6,800 ft elevation, btw.
With e brake on and in neutral, driveshaft moves about 1/4 rotation between back and forth, with clanking comming from t case. U joints seem to be decent shape.
Carb seems to be a little weird, don't know if the secondaries are opening. Could just be a symptom too, thinking they ain't when something v else is robbing the power and they are working. Idk.
She also has a chirping whistleyy sound when you press the throttle, trying g to locate the source of it.
Took cap off couple days ago, missing gasket at the bottom, I replaced it about 3.5-4k miles ago, looked in good shape, no cracks, no black trails, fireing order checked and double checked and it's right, 99% sure of that.


Could the violent shaking and motor movement be as simple as plugs, and header gasket?
Could the carb have gotten gummed up from the exhaust leak and sitting with ethanol fuel? I plan on taking it off and rebuilding it, or at least cleaning it up. Can't afford a kit atm, can the gaskets be reused until I can? The carb has been said to be brand new when I got the truck about 4k miles ago.
Harmonic ballencer had a hair line short tear in it, is that a possible culprit?
Could it be trajny/transfer case related? Motor seems pretty close to being in good running condition.
What about the trimming chain? Who knows when it was replaced, if ever, I haven't checked for play in it yet.
I've done plenty to this truck, and I'm frustrated because she has recently ran great, and then all of a sudden it seems like, trash. Idk what direction to go in at this point, and don't have much funds to keep throwing at things that honestly seem to help for a day, and then overall she gets worse. Next few days she won't have to move much, so I really hope to figure this out. She shakes at times so bad that I would like to park her till I figure it out. But atm, she's my only daily. She went from a rare occasion when she needed to be drove but started every week, last resort vehicle to the only daily. I can't afford to lose this one too, or any expensive repairs. Any help or insight will be appreciated, like I said I'm at a loss rn. Ill see if I can't get a video or two to show what's she's doing.

Start back at the beginning and finish one of the diagnosis tasks...or what I consider regular maintenance.

You mentioned you only cleaned half the fouled plugs. Pull all of them, clean all of them.

Very familiar with undrivable because of oil fouled plugs.

 

[eskimomann209]

If that was the case, some of them screw on non foulers will get him by in a pinch and keep the oil off the plugs, but I not leaning that direction yet.

I went that route because it’s fast cheap and easy. He also seems limited on abilities at the moment. He also mentioned it running better for a few days after putting in the autolites. Hopefully he can diagnose correctly and report back.

 

[Ricko1966]

Where I'd start.Grab a can of carb cleaner spray around the base of the carb and at each intake port, if the idle speeds up you've got a vacuum leak. 2nd Pull the plug wire girdle off. While the engines running pull the wires 1 at a time off the dist. cap listen for the idle to drop.All cylinders should drop fairly equal the ones that don't drop are cylinders that have a problem.Check plug wire resistance, plugs, and compression on those cylinders. If you are afraid you can't pull the plug wires without getting shocked lick your fingers and very briefly touch your headers by the exhaust port, the cold ports are your problem cylinders.

 

[Turt13]

Well, today was a good day. Didn't get to fix the main problem, but did help the truck a bit.
So that's good.And, may not be as exciting for you but.
Today was the first day I went into the scrap yard some since before the accident.
Probably in the top 3 places I like to be.
I checked the t case fluid. Pulled fill plug, and it was bone dry. First thought, oh **** she's dry. Stuck my finger in her hole, and guess what? She was dry. Now I'm panicking. So I quickly pull the drain plug, and got covered with atf, while making a mess on the street at my inlaws. Whoops.
Ill post a pick of something that raised alarm that also came out the drain plug hole. it was a little nylon/other plastic piece, that looked as if the chain had been rubbing on it. T-cases are new territory for me, so Idk the inner workings besides mines a chain one, and I'm guessing it has brake in it attached to the e brake? So, needless to say I have no clue what it would be. Or if there is more...that's a different day.
Continuing, remember I said the brace for the t case that mounts sorta o by the starter was missing a bolt?
Well in the scrap yard I came across a 1/2 ton Jimmy, with a t400 and 208.
What do you know, top of the motor was gone, as was all chevy heads, but underneath I found: the bolt I needed, (none I had would work), a vac mod, (red stripe one ), diff cover bolt I needed, and also snagged couple interior pockets, some bulbs, and Sun visors.
So first, after already fighting it for a hr before we left, I tried to put in the brace bolt. Fought it for another hr. And of course this is the dirtiest part of the truck.came to the conclusion that the last bolt was never lost, just lost its head.
So now being 6hrs away from all my tools, I'm wondering how to get this some bitch out. I've never had to do a bolt extraction anyways. And it's not like it's out in the open. At all. Any ideas, ill find what I need tool wise between family and the pawn shop, (also a top place for me), but how to go about it? Header, driveshaft, tyranny and box are all working against me in that area.
Frustrating af. So I move to the vac mod, install it with little to no problem. Just a fkn mess down there. Didn't touch the e adjustment, on the test drive she shifted better, but still shook.
Went to rear diff to put in bolt, cuz it was leaking from the top. realised I had already done that and attempted to goop up the bolt recently with rtv. That's where she was leaking, so I went to tighten down the bolt.
And then I remembered why it was like that. She was stripped out.
I remember noticing the missing bolt and leak when I bought it. Wth was i thinking.
So now I get to learn how to tap and thread a hole.
so far, truck 2, me 1.
I get up top and do the drivers side header gasket. I couldn't take it anymore. Was more pita then the passenger side. Gasket was trashed on cylinder 7, rest were mediocre at best.
Get that installed, start it up and I have a little victory feeling for a moment.
Slight moment.
She was still making racket, but finally I could hear it.
Sounds like a vavle, but when I got under her, sounded like the bottom end. Yikes. But didn't sound like a rod.

 

[Ricko1966]

Taking out broken bolts my first attempt is see if I can walk it counter clockwise with a hammer and a punch.no? Next I weld a flat washer to the stub and weld a nut to the flat washer and carefully try to walk it in and out in and out until it comes out.Next I'll grind the end flat center punch it drill it and tap it. You have no idea how many people carried in whatever with an ez out broke of in it for us to deal with.If you gotta drill it anyway just drill and tap it.
Just noticed you've never drilled and tapped.Center punch your spot use a sharp bit do not try to change the angle of the drill because you got off a little bit you'll just break the bit off.Use a brand name tap turn it a little bit back it out clean the tap,repeat.Just a precaution.If the tap doesn't want to move, stop, investigate is the hole not deep enough? Did you drill the wrong size hole? Drill bits and taps are too hard to drill out so as I said don't move the angle of the drill and don't force the tap. EZ outs are too hard too drill also but seriously if you have to drill a hole just drill and tap, it's safer.

 

[Turt13]

It sounded less um..just less. Comming from passenger side, might be fuel pump and might have put to long a bolt in the hole near the pump. Maybe it was a fuel rod I'm hearing. Wife says she could feel it more when she had her hand on the pump, I couldn't feel **** anywhere I tried putting my hands that correspond with the noise.
Hoping that's all it it.
Still shakes though. A lot. Never thought of a head gasket going between cylinder s.
No I don't have a thermo, or my compression tester with me, its back home, 6+ hrs away.
Debating how worried I am about what came out the case. I want to drain and refill it, see what's really going on, but if it's about to go, I'd chance it until I get a chance to get the one in the scrap yard. Spend money on fresh fluid then. But I gotta act quick cuz it was the only one, but is there a difference in spline count from 1/2 to 3/4 ton? Can you put case a and case b together and make it work? It's a daily, so it'll have to be done in a day...with me doing it. We will see.
Still shakes, terribly. Checked fo again, it was right.
Shakes At idle, and while moving unless slowing down you can't either notice it or it's not happening. Torque converter..? Flex plate maybe? Just throwing that out there, idek. Not u joints..at least not at idle. Tune issue? I'm a noob with carbs, and don't have a timing gun with me, so I'm in the dark besides my vacuum gauge.
Oil and coolant are Good and not mixed, would that still happen if it's a head gasket between cylinder s? There is what seems to be a little valve train noise, but with how old n beat this truck is, I'm not to bothered by the little noise. May need valve adjustment, but that can wait
Trimming chain or balancer? Who knows? Or has a clue lol.
That's all for today's adventures. I dint take much if any pics, hands were to dirty to touch the phone, and my lady had it. I'll take some tomorrow. Did take a video otw to the scrap yard, before the header gasket so I'm sure it sound like Hell. Maybe ill be able to post til, with the mysterious plastic piece that came out the case. Thanks for your help everyone, feel as if we are narrowing it down or at least headed n the right direction

 

[Turt13]

Drill and welder at home. The bolts is broke under where the head would sit, 1/4 in or more. It was a collard bolt, and when she left, she left her threads inside and a ways in. I can find a drill, may have to drop header to get it to fit in the area, hope won't ruin the new cheapo gasket I just put on lol. Maybe the shaft to. Maybe I can get a flat driver in on it, and like you said tap it out that way. Hmm..

Oh yeah, never has backfired through intake,
If she's tuned the way she is now, no backfires out the exhaust, except maybe a pop after you really get on it, maybe. Glasspacks and 3in though, that along with being tuned to rich, she's been known to have some backfires on deceleration.

 

[Ricko1966]

Okay I'm so confused now the bolts broken under where the head would sit? Pic please.if it's a blind hole your going to need a bottom tap.

 

[Turt13]

Ok so the bolt I got from the scrapyard has a neck without threads, and then threads on the bottom. I'm assuming the last one broke on the neck area, inside the hole, and came out because there was no threads holding in the head,. Does that make sense?

 

[Turt13]

So, this shaking, I'm thinking.
It's gotta be a miss, or timming is off.
Or both.
Maybe even with a vacuum leak I haven't been able to find yet.
Which reminds me,

The transfer case level checks like a differential. Fill it till it comes out, check it with your pinky. NP 208s are very tough cases but they need fluid.
Open it with a big crescent wrench so you dont gotta get back up.

I was referring to the check valve in the brake booster vacuum hose..if youre gonna start chasing .misfire, I suggest to verify the engine grounds first.

Hope this helps!

Likes reading novels...*with pictures!

I got a check valve at the yard, was gonna test each tomorrow and see if I can see a difference between the old and the new/old one,or if carb cleaner is getting sucked in. Ill try pinching the line too.
When I saw it on the truck I realized what you had ment, and snagged it.

Getting New plugs next week. Any recommendations?
I believe that'll do wonders. Wish I had my volt meter to test my wires, they don't seem burnt, but that's just eyeball.
Was supposed to get a set of decent doors too..


$$$$$$$. Even for a chevy. My two bmws may have costed a lot to work on, but Damn, this truck feels like a hole. I'm not even buying much and when I do, it ain't no top shelf ****.

 

[Rusty Nail]

I use AC Delco R45TS spark plugs @1,200 feet.