engine shudder driving me crazy

[hayballflypaper]

2003 silver marauder. 89,000 miles. We rebuilt the head because of the #7 & #8 cyl. A speed shop did the engine work. Put it all back together and in the few days since I've had it it has developed a roughness, a shudder like feeling under light running. Example: taking it easy up to 45 mph. Get it at 40mph and set the cruise and it does it. Accelerate hard and it does't do it. Once in a great while it will do it at idle. Sometimes it does it a lot. Sometimes I think it has gone away and just when I yell out the window YYEESSS!!! It does it again. So, did an on car injector cleaning, replaced the coil boots and spring kit. Still doing it. Will not throw a falt code or check engine light. I need help. Please.

[Blackened300a]

Have your coils checked at a local Ford dealer. One bad coil can cause these issues and never set the CEL off.

[fastblackmerc]

Have your coils checked at a local Ford dealer. One bad coil can cause these issues and never set the CEL off.

+1 - Check your coils.

Consider using these: http://www.lightningforceperformance...s_4_Valve.html

[mcb26]

Have your coils checked at a local Ford dealer. One bad coil can cause these issues and never set the CEL off.

What he said One bad coil

[Egon Spengler]

My guess is coil as well. I had this issue as well... coil!

[hayballflypaper]

thanks guy's . giving up and taking it to the dealer. Thanks for the help.

[texas1]

post results

[whd507]

you might also try greasing the coil boot where it covers the plug. I just changed plugs for the same issue, the plugs looked good, but were installed with the boots dry.

[screamn]

Had same issues with 51K. Was going to just change plugs at first and see what happens but decided to do both plugs and I bought Granatelli pro coils (60000 volts) with connectors already installed in these coils.

Set me back a few bills but didn't have to fuss with each coil. Best yet problem solved!

Car now runs smoother, a little more responsive, and coils are lifetime warranty.

[MOTOWN]

ive been thinking of going the coil route as well the gms connectors are $100 duckets, the gms "hot street" coils are $250 w/connectors!
something to consider

[MM2004]

ive been thinking of going the coil route as well the gms connectors are $100 duckets, the gms "hot street" coils are $250 w/connectors!
something to consider

I seem to recall members going to non-Ford brand coils and were of no benefit besides emptying your wallet?

I stayed with stock coils and have the GMS connectors.



Keep us posted.

Mike.

[MOTOWN]

I seem to recall members going to non-Ford brand coils and were of no benefit besides emptying your wallet?

I stayed with stock coils and have the GMS connectors.



Keep us posted.

Mike.

at this point im on the fence! $100 for cop connectors, or $250 for everything! i wouldnt expect a huge difference on a n/a motor, but on a high psi/sc engine i would think these may produce a stronger spark

[MM2004]

at this point im on the fence! $100 for cop connectors, or $250 for everything! i wouldnt expect a huge difference on a n/a motor, but on a high psi/sc engine i would think these may produce a stronger spark

I see what you're saying and makes sense now.

If you go that route, start a thread detailing before/after experience.



Mike.

[MOTOWN]

I see what you're saying and makes sense now.

If you go that route, start a thread detailing before/after experience.



Mike.

yeah im going to try and do a better job of detailing my mods, and how i feel they help