Engine Problems, Need some Help?

[bjtheman1]

I started noticing a lack of performance as it was getting colder along with a rougher idle. I did some data logging and found misfires on cylinders #7 & #8. Also, cylinder #8 spark during the datalog never changed like the others. The readings never fluctuated just stayed at 10.0 like there was nothing there?

Car has shown no codes as well.

I replaced the fuel filter and spark plugs, no change.
Tested resistance on the coil packs and all were fine.
Did a dry compression test and all cylinders were around 190 psi, when oil was added for the wet test psi did increase by about 10-20 psi.

After the compression test the idle seems a little rougher and it smoked quite a bit from the exhaust, one pipe more than the other. Also, smelled a bit like fuel?

I'm lost and not sure what to look for?

2007 Roush 427R with 50,000 miles. It's the 3V 4.6 with Eaton M90

Here's a pic of the old plugs:

[Lone Star Performance]

What mods are on the car? Ever been tuned?

[bjtheman1]

What mods are on the car? Ever been tuned?

VMP 500 Kit consists of CAI, Pulley, Tune.
3.73's
DSS Driveshaft
Afco Heat Exchanger

I've had this tune since 2011, dynod at Truestreet shortly after and the A/F was spot on. However, I did dyno there again not too long ago and I was running a little rich but nothing significant.

[JC316]

Was it hot or cold when you checked the resistance on the coils?

[bjtheman1]

Was it hot or cold when you checked the resistance on the coils?

Cold

[shumpertdavid]

Rough idle and smoke was likely due to you adding oil to each cylinder. The excess was pumped into the exhaust and the added oil on the cylinder walls and rings would have helped to load each cylinder up on start up. Resistance testing has never proven to be a real world type test on ignition components for me personally because they dont test the parts ability to function under a working load. I use a HEI spark tester to test coil function. If it won't consistantly spark while testing the coil then the coil is weak.

[VaderTT]

VMP 500 Kit consists of CAI, Pulley, Tune.
3.73's
DSS Driveshaft
Afco Heat Exchanger

I've had this tune since 2011, dynod at truestreet shortly after and the A/F was spot on. However, I did dyno there again not too long ago and I was running a little rich but nothing significant.

There's your problem.

[bjtheman1]

Rough idle and smoke was likely due to you adding oil to each cylinder. The excess was pumped into the exhaust and the added oil on the cylinder walls and rings would have helped to load each cylinder up on start up. Resistance testing has never proven to be a real world type test on ignition components for me personally because they dont test the parts ability to function under a working load. I use a HEI spark tester to test coil function. If it won't consistantly spark while testing the coil then the coil is weak.

I switched coils from a cylinder without misfires and it didn't change anything.

[bjtheman1]

There's your problem.

lol, I dyno'd there my but tune was from VMP

[VaderTT]

That's good, TS blows goats.

[Lone Star Performance]

^^ True Story

[76 Maverick]

That's the first i have heard bad about truestreet. Are there stories to go along with the negativity?

[JC316]

Cold

I would retest them hot. I have seen coils and ICM's test fine cold, but go on the fritz when hot.

[Country cracker]

That's the first i have heard bad about truestreet. Are there stories to go along with the negativity?

There used to be before they got deleted because TS was an advertiser.
Dowel pins

[76 Maverick]

I noticed they disappeared but no idea why. What happened? They did a good job on the gears in my Vic....