First real test drive today, after V8 swap.

[termite]

So about that timing light to check for spark....

Why SHOULDN'T I use it?

Speculation here, timing light will show presence of spark but not quality. The hei spark tester, I'd think, would give you a better idea of weak spark vs popeye ate his spinch spark.

 

[Orpedcrow]

So about that timing light to check for spark....

Why SHOULDN'T I use it?

The only reason I see would be it’s failure you to show you quality of spark. But it should definitely be a yes has spark, no has spark indicator.

 

[DeCaff2007]

Understood. Right now, I'm only worried about presence of spark.

Soon as I feel like braving the cold tomorrow, I have but two goals. Check for spark on all eight and then do a compression test.

I'm torn, however, because I don't need to run the engine to test for spark, but it will be faster if I run it and clamp the timing light to the each wire, one at a time. Otherwise, I'm going to have to pull each wire individually and connect the HEI tester. Well... $hi7... which I might as well do because the headers and plugs have to come out for the compression test.

Sheesh....

 

[DeCaff2007]

I used my inductive timing light to check for spark. There's no problems getting the spark TO the plugs. I also had the engine running for a bit, so I need to let it cool down some before digging in deep.

The drivers side headers still get HOT. Like HOT. So much so that I can see singeing on the protective heat shields meant to protect the wires from melting - oddly - only on cylinders 5 and 7.

I also pulled the driver side valve cover. No loose rockers and nothing fell apart this time. I do, however, smell unburned fuel.

Still haven't ruled out bad spark plugs nor bad compression. Those tests are next.

As for the timing, I am 1° advanced with the timing connector UNPLUGGED. I'm at 28° advanced with the timing connected PLUGGED IN.

Alright, cool down time.

 

[HotWheelsBurban]

I used my inductive timing light to check for spark. There's no problems getting the spark TO the plugs. I also had the engine running for a bit, so I need to let it cool down some before digging in deep.

The drivers side headers still get HOT. Like HOT. So much so that I can see singeing on the protective heat shields meant to protect the wires from melting - oddly - only on cylinders 5 and 7.

I also pulled the driver side valve cover. No loose rockers and nothing fell apart this time. I do, however, smell unburned fuel.

Still haven't ruled out bad spark plugs nor bad compression. Those tests are next.

As for the timing, I am 1° advanced with the timing connector UNPLUGGED. I'm at 28° advanced with the timing connected PLUGGED IN.

Alright, cool down time.

That excessive heat on 5 and 7 could indicate that misfires are still occurring on those two cylinders.

 

[Schurkey]

I have an HEI spark tester, I was planning on using a timing light to check for spark.

Why SHOULDN'T I use that same method here?

As said--the timing light verifies "some" amount of spark. The calibrated spark tester assures that you have full power. Rules out "weak" coils and weak insulation.

After I replaced everything under the sun, THAT'S when the turning issued started.

I think, from the way I worded it before, may have sounded like the alignment shop caused the turning problem.

No, I knew this was a result of your work, or the alignment shop.

They should have caught the problem before the truck was given back to you.

The drivers side headers still get HOT. Like HOT. So much so that I can see singeing on the protective heat shields meant to protect the wires from melting - oddly - only on cylinders 5 and 7.

That excessive heat on 5 and 7 could indicate that misfires are still occurring on those two cylinders.

Or it could be that the header tubes are bent in a way that provides more heat to those two spark plug wires.

 

[DeCaff2007]

No problems with spark, at all. I dug out the HEI spark tester. Same spark on all 8 cylinders. Behold:

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[DeCaff2007]

The results of the compression test are in and I don't know what to make of them.

1. 170
3. 125
5. 125
7. 125
2. 120
4. 120
6. 120
8. 140

If it's not too much trouble, I will need help deciphering these numbers. Never see them all over the board like that.

 

[Schurkey]

The results of the compression test are in and I don't know what to make of them.

1. 170
3. 125
5. 125
7. 125
2. 120
4. 120
6. 120
8. 140

If it's not too much trouble, I will need help deciphering these numbers. Never see them all over the board like that.

Re-test #1. If it's still high, retest all the others with a battery charger connected so the engine is audibly cranking at the same speed during each test.

Did you have the throttle opened at least somewhat during this testing? Some guys specify "WFO" throttle, far as I'm concerned there's no need for anything beyond "cracked open somewhat" like you'd do to achieve 1500--2000 rpm.

Do you trust your gauge? (i.e., is is REPEATABLE if not totally accurate?) In other words, will the needle show the same pressure indication if the gauge is tested with the same pressure 20 or 50 or 100 times? Most compression testers sold now use a quick-coupler in the hose. Most of those, use an "Industrial Interchange" (Milton "M" or equivalent) coupler and plug. This is EXACTLY the same as an "Industrial Interchange" compressed-air quick-coupler.

Grab a brass tee or union, whatever male coupler plugs are needed to plug your compression tester into your shop-air system, compare the gauge readings against the gauge on your air compressor's regulator.

I have more than one compression tester.

You must be registered for see images attach

Two compression testers connected to my air compressor. Gauges indicate the same pressure each time they're connected, and agree with each other and the regulator gauge within 5 psi or better.

You must be registered for see images attach

 

[DeCaff2007]

If it's still high, retest all the others with a battery charger connected so the engine is audibly cranking at the same speed during each test.

That's the one thing I don't have. The Wife has a battery "box", meaning it's good for one or two emergency cranks, but then it has to be recharged, itself.

Did you have the throttle opened at least somewhat during this testing?

I have never done that, ever. Don't see that it's going to make any difference with numbers like I've just posted.

Do you trust your gauge?

Yes, I do. I've used it many times in the past without fail.


EDIT: I went back out and tested cylinder #1. It went to 150 this time. Crazy.