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Thinking of doing the unthinkable... *Rotor to cap gap. Normal?*

do a plug reading.... it's actually a huge help when they are very fresh... we do it in the boats all the time.. an hrs run time will tell you a ton... just in the slight hole to hole differences.... if all 8 aren't exactly the same, thats the start.... I'll figure it out from there...

put the truck in base timing at the connector..... then put a pair of gloves on, or get insulated pliers/or wire pliers, and physically just pull each wire off as it's running.. they should all drop rpm's evenly... if any fail to do that, you have an issue with that hole.. whether thats fuel, ignition, valve timing/seating, we'll figure it from there...
 
Ok i'll give it a shot as i dont know if my method actually kills 100% of the spark. Like i said doing my method, i would say 3 made very little difference, 3 made a slightly more noticeable difference, and 2 made a very noticeable difference. I wish i could effectively capture on "film" me going threw this process. But its just so noisy in the videos!
 
Very interesting,

IMAG0314.jpg


IMAG0315.jpg


IMAG0316.jpg


This is as they came out of the motor front to back. The front(1,2) being the near ones.
 
told ya... you need to do a leakdown test... did you do the plug wire pulls?
 
ryoken said:
told ya... you need to do a leakdown test... did you do the plug wire pulls?
Click to expand...

I tried pulling the plug wires! Damnit! It was a quick reminder as to why i hadnt done that yet! Best gloves i had, most insulated pliers i had, shocked the piss out out of myself on the first one and then it slipped out of the pliers so i said fk it and shut it down and pulled the plugs.
 
I can figure it out, but you need to start with a leakdown.. they aren't too much money, or ya may be able to rent one...
 
Bad wires maybe. I can reach in and grab the top of my dizzy and adjust the timing while running with my new ones:dunno: really freaked me out when I reached in to do it. I was thinkin "Man this might hurt", was all good though. havent tried to remove one from the plug though:thinking:
 
y5mgisi said:
I tried pulling the plug wires! Damnit! It was a quick reminder as to why i hadnt done that yet! Best gloves i had, most insulated pliers i had, shocked the piss out out of myself on the first one and then it slipped out of the pliers so i said fk it and shut it down and pulled the plugs.
Click to expand...


:haha: my boss actually likes it..
 
Yea i think auto zone has leak down testers for rent. I'll check it out. Ryoken, your the best man. You help so many people around here. Most notably chief brody. I thank you for your help around here and not just for helping me. You helping others helps me too.
 
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i'm sorry i didn't look at this thread earlier.. if i get some time I'll read thru it and see what's been going on...

sometimes people lose perspective on things and some fresh eyes help... once we determine the cylinders are healthy enough to run ok, especially the valve timing, we should be able to figure it out pretty easily... have you checked resistence in the wires, or new?

you can even pull a plug, put an old one in there, than take the one pulled, put it back in the wire, clamp the plug body to grd, fire it and see how each plug is firing...

but i also have every spark plug tester known to man, inline light, #2 phillips head screwdriver ;) , and i also really like the external lisle ones that ya just hold to the wire for quickie work...

like these..

http://www.google.com/products/cata...a=X&ei=-aPJToveBKXo0QGFm5j3Dw&ved=0CGcQ8wIwAw
 
I just wonder what would cause those two plugs to look totally different then the other 6! Any way, im going to still give this motor a shot cause it would be nice to spend the money i could spend on a new engine, on something like paint. But if stuff doesnt go right soon, i think im going to pick up a 5.3 just after christmas. I would get a different tbi 350 but to find a good running one would cost me about $500. I can pick up a 5.3 for that much and then just have to buy the other stuff like comp and harness and only be into it another grand or so. So, we'll see how it goes. I would like to just get this motor running right! But after 5 years now, its pretty well time to consider throwing in the towel.
 
Hang in there, I really think we are getting close. My hats off to you for sticking it out this far.
I thought I was the only one this stupid stubborn.:D

Its hard to be sure from pics, especially since the plugs don't have much time on them, but you have at least two dead holes I think.

An engine needs three things to run. Fuel, Compression, Spark.
Of course, those need to be there at the correct time and amount.
On a normal engine, I would say you have bad wires or something wrong with the ignition.
Not sure with this one.
I wish some of those old Sun scopes were around. I would love to see the spark voltages and pattern to eliminate or confirm ignition problems.

BTW, you may have bad wires, but its not certain just because you got bit. Supposedly modern wires are so well insulated that you can just handle them with no problems.
I suppose that in that case you could make the case that any wire that shocks you is bad, but I have seen too many otherwise good wires that would put you on the ground.

Remember, the voltage in the wire is controlled by the plug. It builds up from the coil until the plug arcs. At which time it drops to near zero.
When you pull it, there is no arc, so the voltage goes to the maximum the coil can produce.
So a wire you can handle when hooked up, might bite you when you pull it loose.
I doubt you are reading this now, but if so, its a great time to check the wires.
Go outside, crank the engine and look for sparks. Of course, thinking about this, I realize that the plugs are out.

Never Mind.

You have done a compression check, so we know there is enough for the cylinders to fire.
A leakdown test like ryoken wants will not show up a bad set of rings, I don't think, but I suspect he is looking to see where any pressure is going. I agree.
I'm thinking bad intake gasket or crack somewhere.

Don't know your friend situation, but if you have anyone with a similar engine, take your timing light over and ask pretty please if you can see their injector spray pattern.
I have never paid all that much attention to one, but somehow yours looks funky.

Assuming you do have two dead holes, and the compression is good, then you either have bad ignition on those two, or no fuel getting to them.

No fuel, is either a bad vacuum leak, a gasket from hell, or something really strange about the intake.

Hmmmm, don't suppose its a V6 intake??????:dunno:

It is interesting that the front and back plugs on the same side seem to be running rich.

Hang in just a little longer. We may not fix it, but I think we are zeroing in on whats wrong.
 
I think my injector patern looks a little off too. I dont know if it is, but i do have a buddy with a tbi 350 i can look at. I am going to at least check the compression in those two cylinders real quick. Then i would like to do the leak down test in the other six. The plug wires are new. Like a week ago new. I put them on even tho my old ones tested good. When i got bit by the plug wire it was as i was lining it up to put it back on. I didnt have it aimed quite right and thats why i got shocked. I can grab the cap and turn it with out being shocked. I also replaced the intake moanifold gaskets around 6 months ago. No change. I also replaced the TB base gasket around 5 months ago. Again, no change.
 
Just ran out and checked the compression on those two holes. 150 each. I know thats no leak down, but at least that tells us something.
 
Yep, I thought you had replaced the gaskets. It was just too late last night to go back through all the stuff.
I keep thinking there is something fundamentally wrong with this engine. Of course having the cam effectively one tooth off is pretty darn fundamental.

But, if the compression is good, and there is not something weird wrong with the new dizzy, then I am leaning towards something structurally wrong with the intake.

Possibly an internal crack.

Of course, you may have already changed the intake without my remembering it.

I know you don't know much about the history of the engine, other than the last five years.......
But I wonder if the intake was used, or new. If the PO put a brand new intake on when the rebuilt was done, then all bets are off.

You seem to have two cylinders running way rich, but firing. Some others that seem to be running right, and two that act like they are not getting any fuel at all.

And that is just strange.

Actually, I need to find a diagram that shows which cylinders are fed by which injector. That might tell something.
Of course, I don't know which type intake you have.
 
With how much has been going on in this thread its been hard for me to keep up with all of it, but I would have replaced the cam with a stocker by now. also a new timing chan would be installed also.

I had a timing chain go bad in a 350 while a car sat over the winter.

Spring time came and I could get the thing to run worth a ****. I did all kinds of stuff, and couldnt figure it out. Ended up being the timing chain, it had no power and was runnning really rough, popping out of the carb etc.
 
As far as the intake goes, It's the original off the truck. The heads and intake. The motor was a long block that I pulled the 70's heads off of and put my rebuilt heads on. The heads are also the originals off the truck.
 
a compression test is not always indicative of healthy cylinders.... often, but not always... I had a 496 last month with 140 lb's give or take across the board, and every cylinder was only at 25 to 40% on the leakdown... every exhaust seat was fubared..
 
ryoken said:
a compression test is not always indicative of healthy cylinders.... often, but not always... I had a 496 last month with 140 lb's give or take across the board, and every cylinder was only at 25 to 40% on the leakdown... every exhaust seat was fubared..
Click to expand...


I see this alot. Good compression, but major leakage. On the junk I work on its the Intake valves. They Pit from carbon.

I vote leakdown test
 
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