1982 C/K 6.0L Caitlyn Mall Crawler (Interior time)

[folkenheath]

Well, NGK will likely recommend a #5 for 9:1 and a #6 for 10:1, are you are in between, so either should be useable, it shouldn't be a problem where it is at there,

It depends on what your timing is now.

I don't see the plug in person, a picture is not the same. I would lean toward your tune because you shouldn't be having those issues with that plug I wouldn't guess. That doesn't mean you can't, or don't.

 

[Babaganoosh]

Here is screen shots of the timing table and AFR for reference.

AFR

Timing

 

[Babaganoosh]

Ordered a few things today for the fuel system, do you guys think it would be ok running the fuel lines, pump and regulator on the outside of the frame?

ORD got a order from me today, 4 inch springs, tension shackle hanger and extreme shackle.

 

[folkenheath]

Your timing below 1800 is backwards. You have more timing at high load than you do at low load.

This is likely where your issue is coming from.

 

[Babaganoosh]

Your timing below 1800 is backwards. You have more timing at high load than you do at low load.

This is likely where your issue is coming from.

Could you explain this in simple terms? I thought the load was on the left and closer to 0 would be higher load, meaning it would have up to 29 degrees of timing.

 

[Fastereddie]

Could you explain this in simple terms? I thought the load was on the left and closer to 0 would be higher load, meaning it would have up to 29 degrees of timing.

The load is the left vertical column, but 0 is no load, 105 high load. In reality, you won’t hit either end of that chart though.
Atmospheric pressure depending on your altitude will be around 95. When you start it up, your engine vacuum will draw the kpa down to somewhere around 30. Anything above your atmospheric number would be if you added boost. Anything below your idle kpa, would be in deceleration while in gear.

 

[Fastereddie]

For example, I circled the area where your idle would be. (Approx).

 

[Fastereddie]

I know @folkenheath is way more knowledgeable about tuning than me, but I do have a lot of Megasquirt tuning practice on my junk. I’m sure the terminator has a live window where you can follow a “dot” on your VE and timing maps to see what value your ecu is using at that exact moment. I try to make my timing and ve numbers equal in the surrounding four to six bins to stabilize the idle. Does that make sense?

Timing at idle would look like this basically.


20 20 20
20 20 20
20 20 20

 

[Babaganoosh]

Gotcha, yeah it idles around 19 for timing and I always thought that was low...

 

[Fastereddie]

Gotcha, yeah it idles around 19 for timing and I always thought that was low...

Well, I’m just generalizing that 20 number as an example. You basically want to try raising or lowering your idle timing to get the lowest kpa reading. Just like tuning a carb with a vacuum gauge.

 

[Babaganoosh]

Well, I’m just generalizing that 20 number as an example. You basically want to try raising or lowering your idle timing to get the lowest kpa reading. Just like tuning a carb with a vacuum gauge.

Yeah, I'm having a hard time converting from carb to efi tuning. The carb was much easier to learn. I think the vocabulary is throwing me off.

 

[Fastereddie]

Yeah, I'm having a hard time converting from carb to efi tuning. The carb was much easier to learn. I think the vocabulary is throwing me off.

Haha, yeah. There is a whole lotta information to digest. It opens up a world of unlimited adjustments, but also makes it just as easy to change some numbers and blow up your engine.
But timing is timing and fuel is fuel. That never changes.

 

[folkenheath]

I would guess your idle would not have quite that much vacuum with your Thumpr cam and the "chop chop" you wanted.

kPa is backwards compared to inHg in EFI tables. kPa is absolute in the EFI table. So 0 is full vacuum, and it counts up from there, think of it as a pressure measurement, the higher the number, the more pressure

inHg starts at atmospheric pressure, and essentially is negative counting from there. So although the numbers are increasing, its a measure of vacuum, so the pressure is actually decreasing. This is part of the confusion. Think of it as a vacuum measurement, the higher the number, the more vacuum, (less pressure).

I don't know why they even have 105 kPa in the chart for an NA engine, I don't even think it gets that high in death valley. Its like a waste of the chart cells.

Here is a chart I made over a decade ago, it rounds to the nearest integer.



As for your timing, I will make the same recommendation as before....it will get you closer than you are now...

Timing Setup

If you want, you can then manually tune in more timing at low load at idle, and it will probably like it vs the low idle timing. But when you are getting potential pinging down low, and your timing looks like it was setup for a WOT drag pass and nothing else, you need to start over.

I know why they put that little bump up to 29.5 in there, sometimes it likes it in that spot around there. But you probably won't feel that and you don't need to be pushing the timing when you may be damaging stuff right now.

 

[mrk5]

Ordered a few things today for the fuel system, do you guys think it would be ok running the fuel lines, pump and regulator on the outside of the frame?

ORD got a order from me today, 4 inch springs, tension shackle hanger and extreme shackle.

I'm pretty sure @Kay86K5 ran the fuel lines outside the frame on his crew cab. I don't see a problem with it.

 

[Truckman4life]

The factory fuel line on my C30 is on the outside of the passenger rail most of the way.

 

[Babaganoosh]

I would guess your idle would not have quite that much vacuum with your Thumpr cam and the "chop chop" you wanted.

kPa is backwards compared to inHg in EFI tables. kPa is absolute in the EFI table. So 0 is full vacuum, and it counts up from there, think of it as a pressure measurement, the higher the number, the more pressure

inHg starts at atmospheric pressure, and essentially is negative counting from there. So although the numbers are increasing, its a measure of vacuum, so the pressure is actually decreasing. This is part of the confusion. Think of it as a vacuum measurement, the higher the number, the more vacuum, (less pressure).

I don't know why they even have 105 kPa in the chart for an NA engine, I don't even think it gets that high in death valley. Its like a waste of the chart cells.

Here is a chart I made over a decade ago, it rounds to the nearest integer.

View attachment 404196

As for your timing, I will make the same recommendation as before....it will get you closer than you are now...

Timing Setup

If you want, you can then manually tune in more timing at low load at idle, and it will probably like it vs the low idle timing. But when you are getting potential pinging down low, and your timing looks like it was setup for a WOT drag pass and nothing else, you need to start over.

I know why they put that little bump up to 29.5 in there, sometimes it likes it in that spot around there. But you probably won't feel that and you don't need to be pushing the timing when you may be damaging stuff right now.

Thank you, I will make some adjustments and post up what I come up with. I want to read more on this.

The drag wot comment is exactly what I thought it was setup for, it runs great at WOT but lacks in the middle where it belongs 90% of the time.

 

[folkenheath]

Thank you, I will make some adjustments and post up what I come up with. I want to read more on this.

The drag wot comment is exactly what I thought it was setup for, it runs great at WOT but lacks in the middle where it belongs 90% of the time.

Also, as you know, the engine makes the most vacuum at idle or most likely part throttle cruise for you.

So the more vacuum, or less pressure, the higher the load. At WOT there is no vacuum, full atmospheric pressure. This is highest load. Then fill in in between.

I would not make some adjustments from yours, I would start over. Its whacked. Its only 3 numbers to start over, adn then tweak it from there if you want to add more timing at low load idle for instance, is the first thing I would do. It will want more timing at idle and very low throttle, but not more timing under load at low RPM. That can be bad.

 

[Babaganoosh]

Also, as you know, the engine makes the most vacuum at idle or most likely part throttle cruise for you.

So the more vacuum, or less pressure, the higher the load. At WOT there is no vacuum, full atmospheric pressure. This is highest load. Then fill in in between.

I would not make some adjustments from yours, I would start over. Its whacked. Its only 3 numbers to start over, adn then tweak it from there if you want to add more timing at low load idle for instance, is the first thing I would do. It will want more timing at idle and very low throttle, but not more timing under load at low RPM. That can be bad.

Should I use the idle, cruise and wot the tuner put in then just properly blend it together?

 

[Babaganoosh]

Messing with the numbers and seeing the effected area on the graph makes sense now, just needed to visualize it.


I took the tuners numbers and put them in then smoothed it over so it wasn't as hard of a transition. Going to try this and see what it does around the block.

 

[Babaganoosh]

It actually runs a lot smoother now... one thing I did notice at 25 mph with my foot off the gas coming to a stop sign it would dip down to 11 degrees at low RPM