Engine juddery, loss of horsepower.

[Crashtd420]

None-zero if the pictures you have are too big try taking a screenshot shot of the picture, and post that one..  for some reason it has worked for me... sometimes I have to zoom in slightly to remove extra crap in the background of the picture...

[None_zero]

10 hours ago, datzenmike said:

So it closes initially when cold and trying to start? After it warms up is it fully open? choke plate up and down?

I will check today so I can be sure I'm giving an accurate answer. Still haven't got pictures yet, but I wanted to say, this mornings drive to work was not bad it ran at what I'd call its peak performance (peak being relative) until about mile 16 then it started running rough. Is it possible that it simply is poor circulation of coolant and despite the reading on the temp gauge I'm just overheating and that's what's causing this particular symptom, and the juddery loss of power from previous mornings was a bad connection to the heater plate on the carb which was icing over and not functioning properly?

[None_zero]

Given the variety of failure types and circumstances I must be looking at problems from more than one source right? Ever since I messed with the wires on the heater plate the juddery condition has abated it seems and now I'm just getting what feels to me like over heating. I don't really know how to describe it. It just feels like everything is moving to freely and it shakes a bit and sounds off. The only other thing that I've done that could be an issue was set the valve lashings and I'm not 100% sure I got that right. I don't know If that could play into any of the symptoms or not but I haven't redone it yet to ensure accuracy because by the time I got home it was getting dark and the temp was dropping. So after work will be the first chance I get to adjust it 

[datzenmike]

49 minutes ago, None_zero said:

I will check today so I can be sure I'm giving an accurate answer. Still haven't got pictures yet, but I wanted to say, this mornings drive to work was not bad it ran at what I'd call its peak performance (peak being relative) until about mile 16 then it started running rough. Is it possible that it simply is poor circulation of coolant and despite the reading on the temp gauge I'm just overheating and that's what's causing this particular symptom, and the juddery loss of power from previous mornings was a bad connection to the heater plate on the carb which was icing over and not functioning properly?

 

Engine temperature won't affect running to that degree.

 

44 minutes ago, None_zero said:

Given the variety of failure types and circumstances I must be looking at problems from more than one source right? Ever since I messed with the wires on the heater plate the juddery condition has abated it seems and now I'm just getting what feels to me like over heating. I don't really know how to describe it. It just feels like everything is moving to freely and it shakes a bit and sounds off. The only other thing that I've done that could be an issue was set the valve lashings and I'm not 100% sure I got that right. I don't know If that could play into any of the symptoms or not but I haven't redone it yet to ensure accuracy because by the time I got home it was getting dark and the temp was dropping. So after work will be the first chance I get to adjust it 

 

As long as the lash is not too tight and holding a valve open when it should be closed. Warm the engine for 15 min or go for a drive. A 0.012" feeler gauge should just barely slip in between the rocker and the top of the valve.

 

As to the mixture heater it's below the carburetor so does not affect it. It does however warm the intake air and help vaporize the fuel droplets making for a better running engine initially when the engine is cold. Once warmed up the engine won't need this.

 

As to the gauge trust that it's reading correctly.

[DwayneOxford]

On 2/13/2023 at 10:54 AM, None_zero said:

It's an 83 720 pick up with egr deleted air-conditioner deleted windshield wiper fluid reservoir deleted. Power steering deleted (if it ever had it) pretty much every sensor on it is suspect but most of them are just bypassed. I think the oil pressure light works.. so to answer your question yes I do get white smoke when I first start it. It goes away once it's warmed up. Maybe has a bluish tint I'm pretty sure I'm burning oil but not so much that I have to add oil every week or anything. There is no water in the oil and the radiator doesn't bubble if you run it with the cap off 

 

The only other noteworthy thing I can think of is how much carbon buildup I get on the spark plugs. And in the oil. I can change the oil and drive it twice and the oil is black like it's been in there for 6 months. I've tried adjusting the choke, adjusting the air fuel mix adjusted the timing. Every thing I could possibly think of to improve the amount of carbon and nothing seems to work 

 

I tried replacing the spark plugs, then increasing the gap. Also neither had a positive effect on that situation 

RE. Carbon on plugs and blacking the oil. Have you checked compression?

[datzenmike]

On 2/13/2023 at 8:54 AM, None_zero said:

 

The only other noteworthy thing I can think of is how much carbon buildup I get on the spark plugs. And in the oil. I can change the oil and drive it twice and the oil is black like it's been in there for 6 months. I've tried adjusting the choke, adjusting the air fuel mix adjusted the timing. Every thing I could possibly think of to improve the amount of carbon and nothing seems to work 

 

I tried replacing the spark plugs, then increasing the gap. Also neither had a positive effect on that situation 

 

Carbon is unburned fuel. So either...

 

The choke is on too much or never off, or carburetor flooding. What is your gas mileage.

 

How far do you drive per trip? Plugs are self cleaning but if you only drive it 3 or 4 miles every trip the choke is never off and they never get the chance. The engine needs about 10 min to get up to temperature and the choke off. Easy enough to look at the choke and see if it's warmed up and turned off. Take for a longer drive.

 

While under the hood look at the round glass on the front of the carburetor. When idling the fuel level should be in the middle.

[MikeRL411]

40 minutes ago, datzenmike said:

 

Carbon is unburned fuel. So either...

 

The choke is on too much or never off, or carburetor flooding. What is your gas mileage.

 

How far do you drive per trip? Plugs are self cleaning but if you only drive it 3 or 4 miles every trip the choke is never off and they never get the chance. The engine needs about 10 min to get up to temperature and the choke off. Easy enough to look at the choke and see if it's warmed up and turned off. Take for a longer drive.

 

While under the hood look at the round glass on the front of the carburetor. When idling the fuel level should be in the middle.

 

Gee! You are making ARCO Graphite motor oil in your engine!

[None_zero]

22 hours ago, datzenmike said:

So it closes initially when cold and trying to start? After it warms up is it fully open? choke plate up and down?

Well it was open more than I thought. And once hot fully open up and down yes. I need a quick answer on one thing I'm resetting the valve lashings to make sure I got it right when setting the fourth cylinder to TDC are the valves all closed then also?

[None_zero]

2 hours ago, MikeRL411 said:

 

Gee! You are making ARCO Graphite motor oil in your engine!

Mileage hard to pin down with no odometer but I calculated based on consumption and Google miles during the winter inwas getting as low as 10mpg 

[None_zero]

3 hours ago, DwayneOxford said:

RE. Carbon on plugs and blacking the oil. Have you checked compression?

No I haven't I assume it's not great since when the truck is off and in gear on an incline every 10 or 15 secs it will lurch down a little 

[None_zero]

@datzenmikeI found the answer about the fourth cylinder on another thread.

[None_zero]

I might be getting blessed with a reprieve. There is a jeep parked at my work that just sits there. I'd asked the owner if they'd be interested in selling it. And if what I'm hearing is correct they've decided to give it to me. One of the perks of driving a truck that looks like mine.... people give you pity cars. If that goes through I'll be able to do what I want to do which is ask questions get answers and then affect repairs. Instead of the way I've been doing it. Ask questions and then mess with things and then read the answers and try to unbugger the things I buggered in the interim

[datzenmike]

46 minutes ago, None_zero said:

Mileage hard to pin down with no odometer but I calculated based on consumption and Google miles during the winter inwas getting as low as 10mpg 

 

2wd should be over twice that.

[None_zero]

Yes i used to get closer to 20 mpg but that was interstate. My drive to work passes through a lot of 30mph zones and stop and go so I figure some of it is just the conditions 

[None_zero]

It had been leaving black spots behind it when warming up but adjusting the choke changed that. Although I adjusted it back today on the ride home and my smoke changed back to black on start up. I'm hopeless. I got home engine hot got it on TDC pretty quick and set the first 4 spots then moved it until fourth cylinder was at the top then I start thinking oh shit are all the valves supposed to be closed now... does it also need to be a compression stroke. Now I've turned it so many times I don't have a clue where it is. And I remove the #1 plug to go back to TDC and start over even enlisted the woman to sant watch at the plug hole and tell me when it hits the top. Round and round we go umpteen turns later I've never hit the all valves closed again. And now it's raining. So that's grand 

[None_zero]

5 hours ago, datzenmike said:

 

Carbon is unburned fuel. So either...

 

The choke is on too much or never off, or carburetor flooding. What is your gas mileage.

 

How far do you drive per trip? Plugs are self cleaning but if you only drive it 3 or 4 miles every trip the choke is never off and they never get the chance. The engine needs about 10 min to get up to temperature and the choke off. Easy enough to look at the choke and see if it's warmed up and turned off. Take for a longer drive.

 

While under the hood look at the round glass on the front of the carburetor. When idling the fuel level should be in the middle.

My daily drive is 17 miles one way.

[datzenmike]

"My daily drive is 17 miles one way."...... then your mileage should be closer to 20 MPG, better even.

 

 

You only have to turn the engine once if you follow my suggestion, that's the beauty of it.

 

Set TDC compression stroke on #1 cylinder. Cylinder one, both valves should be closed and both cam lobes pointing at 8 and 4 o'clock as viewed from the front.

 

Set both valves on cylinder #1

Set the intake on cylinder #2

Set the exhaust on cylinder #3

 

Turn engine exactly ONE full turn to TDC

 

Set exhaust on cylinder #2

Set intake on cylinder #3

Set both valves on cylinder #4 DONE

 

Did you look at the round glass window on the front of the carburetor????? Where is the fuel level???

 

Did you check where the choke is when engine warmed up???? Should look like this...

 

 

NOT LIKE THIS...

 

 

 

[None_zero]

Ok then the choke was correctly positioned and I messed it up earlier. That's easy to fix though. I finally got fed up trying to turn the crank between the fan and radiator and removed radiator. I have some blue devil to flush the system with anyways I just wasn't planning on doing it tonight. Ok I think I got the tdc position correct now what is the cold set on intake and exhaust sides since it's long since cold now 

[None_zero]

Also I can't get the 008 into the first four now that it's cold does this mean I set them too tight when hot?

[None_zero]

When cold the choke stays closed no matter where I position the "rich" "lean" adjustment at the back is this the way it should be?

[datzenmike]

0.008" intake and 0.010" exhaust COLD. When at operating temperature the clearances open up to 0.010" and 0.012"

 

 

Right now the cold position doesn't matter. Does it open when warmed up??? like the first picture.

[None_zero]

Yes it will 

[None_zero]

15 hours ago, Crashtd420 said:

None-zero if the pictures you have are too big try taking a screenshot shot of the picture, and post that one..  for some reason it has worked for me... sometimes I have to zoom in slightly to remove extra crap in the background of the picture...

I'll try that 

[DwayneOxford]

7 hours ago, None_zero said:

When cold the choke stays closed no matter where I position the "rich" "lean" adjustment at the back is this the way it should be?

My experience is the choke pull off is inop.

It's the unit the top vacuum hose goes to. It should open the choke like 1/4 inch soon's it starts. I had to put a manual choke on my '85. Carb on mine is such that it's not needed much.

Have you got any kind of manual?

[None_zero]

Top vacuum hose? Can you be more specific. Are you talking about the one that runs out along the Intake on the air cleaner to the vacuum valve positioned at the opening?