Poormanslongbed

I have a similar problem. Mines at 21k though. I've replaced fuel filter, air filter, coils and plugs, and have also cleaned TB and Mass air flow. Still same problem..

Summers22

iTrader: (2)

Ford is VERY proud of their Motorcraft COP's and the reason is, they work, perfectly. 1000HP Mustangs still use stock COP's. But at about $60-$80 each, people are sometimes forced to choose aftermarket for cost alone. I just replaced mine with a set from a 2012 Mustang because he wanted MSD's for his twin turbo set-up and they only had 20K on them. Got all 8 for $120.

Summers22

iTrader: (2)

May be an injector or clogged cats.

cj152290

Just an update: I did buy the MSD. For the price and assumed quality from MSD I felt it was the best way to go. After install, my truck is more responsive but I still have a bit of a rough idle. Im gonna chase down some obvious stuff like intake clean, fuel filter, etc.


The improvement in response has more to do with replacing worn out coils (I found out one had already been replaced with cheap aftermarket) and my number 4 plug was gapped at .062 instead of .054. other than that the plugs I took off were almost perfect.


The MSD has only been on there for a day so I can not speak of longevity, but initial review would be good.

CountyMounty

Why not try changing just the plugs and coil boots first to see if that fixes the issue. This is assuming 1) the money is an issue, coils are expensive 2) that your going to do it yourself 3) that you will be able to find the time to then do the coils if needed. I have read many post from people that have said plugs and/or coil boots fixed it for them. I just tried this approach and sadly for me it seems to have not worked, I still have a miss or shutter, its not that bad but noticeable. Like you I have had absolutely no codes and no other symptoms to help diagnose the problem. I have already done other basic maintenance so probably coils will come next.

It was worth a try for me, of course with only 53,000 on my 08 I really didn't want to have to replace all coils. It didn't seem to work for me but it might for you. The job itself was quite easy compared to other plug changes I have done. Of course I have an 08 with the one piece plug yours will not be as easy but if you were going to change plugs anyway why not give it a try. I have also read where people have cleaned up the contact on the coil and that helped. Good luck to both of us figuring out our shutter.

HA started this post and got busy with something else and see you already did the work, oh well will leave the suggestion for someone else. I will have to look at the MSD as an option to see what I think.

cj152290

Thanks for the suggestion. Money was a bit of an issue, but I would rather have done the job only once and know that I can mark this off of my list.


I still have my shimmer at idle. It is not as bad, but still there. Still no codes.


Eventually I will check the Cats like Summers22 suggested. And do a full intake clean on it as well. I have run FI cleaner, cleaned the TB, changed the fuel filter, running a K&N ( only 1000 miles on it), and cleaned the MAF. As well as the Coils and plugs.


The improvements in drivability tells me that these steps were needed. Throttle is more responsive, acceleration is more smooth, and down shifts less often and quicker. But my original quest is to get rid of this shimmer at idle.

ceasefire49

Have a good friend that put the accels in and has had them in for two years without problems. I also have bought the Factory part and it failed within 3 months..denso makes a real good replacement for around 22 bucks

Summers22

iTrader: (2)

Another and more likely culprit may be O2 sensors, especially at 170K. You only need to change the 2 "upstream" sensors, closest to the exhaust manifolds.