TBI rebuild

[tsr2185]

Could be a valve. Or a stuck lifter or a bent pushrod or a flat cam lobe or a bad rocker arm or a pulled rocker stud or a weak valve spring etc...
Could also be a bad plug or wire or even a bad dist cap.
A leakdown test will tell you which cylinder is the problem if it is a mechanical issue and not ignition related.
Set the timing back to zero and do the proper reset procedure.
Pull all of the plugs. Dont mix them up keep them in order of which plug came from which hole.
Look for any differences between the plugs. If its been running rich you might not see anything but its worth a look.
Check the gap on all of the plugs.
Since they are a bit of a pain to get at it isnt unheard of to accidently bang the gap shut while putting them in.
With it at operating temp, pull the wire of each plug one at a time and see if that stumble changes.
If not, put it back on and try the next one.
Do all 8 of them.
Be carefull doing this. I recommend getting a plug boot tool. pull them from the plug. not from the cap
If you pull a plug, and the stumble goes away or changes. That is the cylinder.
If you narrow it down. You have a couple of options.
Stick a brand new properly gapped plug in and see if it still stumbles.
If it does, put a different good plug wire on it.
You can also move that plug to a different hole and see if the misfire follows it.
You can do the same thing with the wire.
See if you can make it misfire on a different cylinder.
I get it, not everyone has a scanner though you should.
But that takes waiting on Ebay and a learning curve and sime time to figure it out.
Not everyone has the equipment to do a leakdown test.
This is old school side of the road broke ass tricks.
And they work too!

I've pulled plugs twice. I dont disagree with banging the gap close cause the heat shields are SOBs and likes to jam the spark plug socket. I will try my best to identify the weak cylinder with the ignition system and go from there.

I bought a non running truck I really didnt need for 1000$ I would absolutely not be surprised that the engine needs re building. Just my kind of luck....lol

I get obsessed over stuff like this and hard headed about the problems NOT being major.

Oh well I'll figure it put sooner or later, or just get mad and run the **** outta it till it dpnt run no more and drop a better engine in there...

I used to get excited ordering new parts to try and resolve it. The wife started getting mad about all the money I'm spending on it, and me to after ordering parts 10-15 times..

 

[Erik the Awful]

If you pull a plug, and the stumble goes away or changes. That is the cylinder.

That's backwards. If you disable the ignition on one plug and it doesn't change, that's your dead cylinder.

 

[tsr2185]

I really must seem like a duma$$ to u guys. Sorry, I literally have to sneak away to do any work on the damn thing lol. I like to get a plan for every escape I do. You guys really are a huge help!!!

 

[thinger2]

That's backwards. If you disable the ignition on one plug and it doesn't change, that's your dead cylinder.

Yep. If its totally dead. But, if its a random misfire at that cylinder and you pull the plug you should be able to notice the difference too.

 

[thinger2]

I really must seem like a duma$$ to u guys. Sorry, I literally have to sneak away to do any work on the damn thing lol. I like to get a plan for every escape I do. You guys really are a huge help!!!

Not at all my friend. At one time or another, none of us knew **** about mechanics.
Nobody was born with a silver torque wrench in thier hand.
There are many things I cant do.
I cant landscape or grow things at all.
I can kill petrified wood.
If my wife ever leaves me Im gonna have to pave the whole place.
Ive been in construction for decades.
I cant tape and mud drywall or lay a decent bead of caulking even if at gunpoint.
Ive been playing the guitar for 45 years.
I suck at it.
When I was young, I worked on charter boats.
My coworkers signed a petition banning me from cooking on commercial vessels upon the navigable waters of the United States and Canada to a distance of 200 nautical miles offshore.
I signed it to keep my job and cleaned bilges for the next 5 years.
And I bet if I went to your job I wouldnt know **** about it and you would have to help me.
Dont let the frustration get you down and dont let anybody **** on you because they think they have some god given superiority.
There is something that you are great at and they arent.
Keep at it and you will get it.
All respect from me bud, You are trying instead of giving up

 

[tsr2185]

Got to sneak away a little bit and re check some more grounds. The rear light ground is smashed between the frame and the hitch lol. May explain my turn signal hyperflashing. Couldnt find the fuel pump ground (probably cant see with bed on). All the firewall grounds seem good and just need to redo my firewall to head ground. Any more grounds I'm missing?

All the ecm and sensor looming is rotted away and I wpuldnt be surprised if my heat related misfire is due to this.

Also ettempted to pull plugs with a vaccum guage on and boot puller with gloves, and got shocked like a MF'er! Gonna do the shurkey trick but need to get some nails long enough and a spark light/wire.

I also went ahead and pulled the trigger and ordered ac delco cap rotor and pickup coil. It definitely only misses when warm. If it were a valve problem would the misfire be steady and not random? I'm starting to assume(hope) its heat>ignition related.

If I'm at a lost and nothing else works, my local shop can perform a leakdown test for me.... I dont have the time nor knowledge for that. And even my wife admitted to me sending it to the shop now lmao.

 

[tsr2185]

Not at all my friend. At one time or another, none of us knew **** about mechanics.
Nobody was born with a silver torque wrench in thier hand.
There are many things I cant do.
I cant landscape or grow things at all.
I can kill petrified wood.
If my wife ever leaves me Im gonna have to pave the whole place.
Ive been in construction for decades.
I cant tape and mud drywall or lay a decent bead of caulking even if at gunpoint.
Ive been playing the guitar for 45 years.
I suck at it.
When I was young, I worked on charter boats.
My coworkers signed a petition banning me from cooking on commercial vessels upon the navigable waters of the United States and Canada to a distance of 200 nautical miles offshore.
I signed it to keep my job and cleaned bilges for the next 5 years.
And I bet if I went to your job I wouldnt know **** about it and you would have to help me.
Dont let the frustration get you down and dont let anybody **** on you because they think they have some god given superiority.
There is something that you are great at and they arent.
Keep at it and you will get it.
All respect from me bud, You are trying instead of giving up

Amen to than man, I agree!

Thanks

 

[Erik the Awful]

Yep. If its totally dead. But, if its a random misfire at that cylinder and you pull the plug you should be able to notice the difference too.

You'll also notice a difference when you disconnect the good cylinders. You'll notice LESS of a difference when you disconnect the cylinder that's randomly misfiring.

 

[thinger2]

Got to sneak away a little bit and re check some more grounds. The rear light ground is smashed between the frame and the hitch lol. May explain my turn signal hyperflashing. Couldnt find the fuel pump ground (probably cant see with bed on). All the firewall grounds seem good and just need to redo my firewall to head ground. Any more grounds I'm missing?

All the ecm and sensor looming is rotted away and I wpuldnt be surprised if my heat related misfire is due to this.

Also ettempted to pull plugs with a vaccum guage on and boot puller with gloves, and got shocked like a MF'er! Gonna do the shurkey trick but need to get some nails long enough and a spark light/wire.

I also went ahead and pulled the trigger and ordered ac delco cap rotor and pickup coil. It definitely only misses when warm. If it were a valve problem would the misfire be steady and not random? I'm starting to assume(hope) its heat>ignition related.

If I'm at a lost and nothing else works, my local shop can perform a leakdown test for me.... I dont have the time nor knowledge for that. And even my wife admitted to me sending it to the shop now lmao.

Fix the wiring and the grounds before you pay for a leakdown test.
Too me this sounds more and more like an electrical or maybe vacuum problem as opposed to an internal mechanical problem.
Another test you can do, reset the base idle to 0 degrees with the distributor wire disconnected.
Do this with it warmed up so it is in closed loop.
Does it misfire?
Dont grab an HEI wire when it is running.
That was the part about being carefull.
I should have explained that a little better.
Sorry bud.
The first time I did that I was standing in a puddle of water in a piss down rain storm.
Had a wrench in my hand and set my hand on some bare metal when I pulled a plug.
Blue sparks shot out of my fingertips.
It was really wierd but my friends enjoyed it.

 

[thinger2]

Forgot to mention some of the other forty seven things that can cause a misfire.
Plug wires not seperated and laying on top of each other, wierd little cracks in the cap, malformed contact in the cap.
Split plug boot amd on and on.
Chased a misfire on a small block ford for a couple of days and it turned out to be a distributer contact that was wiggling around in the cap like a loose tooth.
I think the old school diagnosis tricks are a great way for new people to learn about engines and maybe, maybe find the problem.
Believe it or not, I do agree that you really need to develop the ability to get live data and understand what it means.
What I think is ****** is when somebody comes on to this forumn with a legitimate question and admits they dont know anything and they get a big **** you buy a scanner.
And then you get off on some warped notion that you shut them down and taught them a lesson.
You strange screwy old *****.
You have thrown away and abandoned everything that made you amazing and grand and incredible and unique when you were young.
Do you ever think about those times?
Do you remember what it was like.
I do.
It was all ******* grand and amazing.
What have you done to pass on that world to the next generation you *****?
What did you do today?
Whining and bitching doesnt count.