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Discussion Starter · #1 ·
While idling; I've pulled cylinders 5 and then 6 plug wires individually and there's no difference in idle speed. Both cylinders have 150psi of compression. Plugs have been changed twice. Plug wires, coil and tfi have been changed as well. I tested spark on all cylinders with the tool that goes between the plug and plug wire. Spark is orange on all cylinders. I haven't done a leak down test. Car ran great right up to this point. It's weird that two cylinders side by side are affected and they also fall in line in the firing order. Valvetrain?
 

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Discussion Starter · #3 ·
if its got 150psi compression, i doubt the leakdown would be an issue. I also doubt the valvetrain would be an issue because you have compression. I would use a noid light to verify you have injector pulse on those 2 cylinders. How do the plugs look in those 2 cyls?
I performed an injector pulse test via TunerStudio. All are pulsing. There's wet gas on plug 6. Plugs barely have any color.
 

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Discussion Starter · #6 ·
You'd think with 150psi of comp the valvetrain and cylinder compression would be fine. Maybe it's not throwing a hot enough spark? It's *** but did you try a screw driver trick to visually see how much spark is going to each wire? Could be cap/rotor?

*** is stared out?! Come on. How am I supposed to type "you might be a ***" jokes.
Are you referring to pulling a wire off the cap and jumping the spark to a screwdriver?
I used this to test spark:
Photograph White Hood Light Motor vehicle
 

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Discussion Starter · #7 ·
Crazy thought, if an intake or exhaust valve wasn't opening (but other was), could you still get full compression?
I'm not the best at visualizing things like that. Tight valve, loose valve, sunken seat? My brain hurts.
 

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Discussion Starter · #9 ·
I took a flashlight and shined it into the cap while in total darkness. I found no cracks for what it's worth.
 

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Discussion Starter · #10 ·
Pull the valve cover off and look for something weird.

Plug wires in the proper place? Lol
Plug wires have been triple checked for firing order. I had the valve covers off and gave the valvetrain a quick look. There was no odd wear on the rollers or what I could see of the pushrods. I told myself that I should check lash but I didn't. I'm wishing I did now.
 

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Discussion Starter · #12 ·
I just started the car in pitch black and didn't get a light show around the cap, wires or plugs.
 

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Discussion Starter · #13 ·
I'm sure my thought was off the wall and rediculous.
But, I was thinking if you wiped a cam lobe (or 2), or broke a rocker, collapsed lifter.......something that would prevent a valve from opening.

Could you still get good compression results if only one of the valves was opening/closing?
Good question. Usually if there's a wiped lobe; I hear popping out of the tailpipes at idle. I don't have that.
 

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Discussion Starter · #15 ·

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Discussion Starter · #18 ·
he has compression.

loosen the rockers on the cylinders and close the valves. apply air to the cylinder. listen for a massive leak out of the intake or exhaust pipe. orange spark is a weak spark. should be bright blue

take the plug out and verify the spark is actually happening.
I think the orange spark is due to the type of bulb in the tool shown above. When I pull a wire off of the cap; the spark is blue and jumps quite a gap.
Can't I rotate the engine by hand to close the valves?
 

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Discussion Starter · #19 ·
Have bright white spark at plugs. Just checked.
 
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Discussion Starter · #26 ·
after that check noid.

if noid is good, do a fuel pressure drop on the affected cylinders. you need a fuel injector tester and a pressure gauge.for this. they are inexpensive.

one thing at a time though.
TunerStudio has an injector test function. I ran the test and verified all are pulsing (clicking).
 

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Discussion Starter · #31 ·
I'm just throwing this out there, have you contacted a priest, bishop, rabbi, or other preferred deity for assistance?
No, but I did load the 308 with armor piercing rounds. I wonder if it will split the block? :unsure:
 

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Discussion Starter · #32 ·
Found a bad plug wire and replaced it but it still runs rough. Brand new Ford Racing wires = junk!

Put the factory coil back on and it nearly knocked me on my arse when pulling a wire off of the cap. All plugs are wet with fuel. I just swapped them out with no luck.

Just ran another compression test on all cylinders. Only one cylinder was below 50psi. It was 46.

Tomorrow; the valve covers are coming off.
 

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Discussion Starter · #37 ·
You may want to consider a new set of any replacement plug wires, and stay clear of any “performance” wire. I would not rely on just a compression test, a better test would be an audible relative compression test, remove fuel and crank for 10seconds and listen carefully
I have a new set of wires to try tomorrow. Relative compression test? Throttle blade open or closed?
Pull fuel pump fuse and bleed off pressure? Crank for ten seconds and turn the key off and listen?
 

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Discussion Starter · #40 ·
Did it run before? I know you had issues with bad injectors, but did it run after you replaced them?
It hasn't run right since before the original injectors. I pulled the original injectors to see if any were bad. I had them tested and they were fakes. Surprisingly enough; the car ran well with the fakes.
I did have issues with backfiring when getting into boost or possibly just higher rpm's?
 

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Discussion Starter · #43 ·

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Discussion Starter · #45 ·
You repinned some of the 60 pin connector right? Some of which were fuel injector pins. Maybe they got switched.
I ran an injector pulse test with Tuner Studio twice. The correct injector clicked each time.
 
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