codyhuntsaz Report post Posted August 1, 2020 I need some diagnostics done to my 2004 F150. I’ve replaced the plugs and coils and the MAF sensor based off another shops recommendations and I still have a rough idle. Looking for a good mechanic to diagnose the rough idle. I’m in Gilbert Higley/Elliot area. Work off Dobson/Broadway. Share this post Link to post Share on other sites
More D Report post Posted August 1, 2020 I suggest putting an ohm meter to the coils to ensure they are within spec? Even when new they can be out of wack. Share this post Link to post Share on other sites
Beaton Report post Posted August 1, 2020 Do you have a check engine light?. Im not a mechanic by trade but I work on them a lot. Could be an intake gasket or a vaccum leak. Ford is notorious for have there plastic vaccum lines break. The shop i trust is in surprise. I dont know anyone in the east valley 1 1 Share this post Link to post Share on other sites
Beaton Report post Posted August 1, 2020 More D is correct also. My daughter's ecoboost had a new coil with a pinhole in the coil boot. I fought it forever and finally took it to my dad who is a mechanic and he found it. It had a bad miss under acceleration and no check engine light. Share this post Link to post Share on other sites
codyhuntsaz Report post Posted August 1, 2020 22 minutes ago, More D said: I suggest putting an ohm meter to the coils to ensure they are within spec? Even when new they can be out of wack. I will try that. Thanks Share this post Link to post Share on other sites
codyhuntsaz Report post Posted August 1, 2020 22 minutes ago, Beaton said: More D is correct also. My daughter's ecoboost had a new coil with a pinhole in the coil boot. I fought it forever and finally took it to my dad who is a mechanic and he found it. It had a bad miss under acceleration and no check engine light. No check engine light. I have suspected a vacuum leak, but don’t know how to find it. When I originally had the diagnostic done I had a real bad stutter around 2000 RPMs and it progressively got worse until it started to stutter through the whole RPM range. That’s when I changed the plugs, coils and mass airflow sensor. That solved 90% of the problems, but now the stutter is at idle , it’s better when the truck is completely warmed up, but still noticeable. Before I did all that work to it, and I forgot to mention that I also cleaned out the throttlebody, it idled at about 500 RPMs and at idle will drop down to about 300 RPMs and stutter, now it idles at about 600 RPMs and drops down to 500 RPMs, when it’s warmed up it idols in about 750 RPMs and doesn’t drop down and stutter as much. Share this post Link to post Share on other sites
muledeerarea33? Report post Posted August 1, 2020 Don’t look for a mechanic. Try to find a technician. For a vac leak, spray all the lines and intake system with brake clean or carb and choke clean, if the idle raises then you’ve narrowed down your vac leak. Rough idle could also be a timing issue on that year of ford. Could be defective parts as stated previously. Get a good diagnosis from a good shop. If you trust their diag and want to fix it yourself to save money, make sure you replace the parts correctly and don’t break other stuff on accident. 1 Share this post Link to post Share on other sites
Lucafu1 Report post Posted August 1, 2020 I hope you used motorcraft plugs or something good (not autolites). Anyways there is a vacuum line in the back of the intake that slips off or comes apart. I would look there. Share this post Link to post Share on other sites
ctracingraptor Report post Posted August 1, 2020 I’ll fix it for you but I’m really far away... 1 Share this post Link to post Share on other sites
Beaton Report post Posted August 1, 2020 Vacuum leaks can be hard to track down. With it getting a little better with it warmed up it may be a leak at an intake gasket. I hope you find it. 1 Share this post Link to post Share on other sites
Beaton Report post Posted August 1, 2020 Also if you cleaned the throttle body sometimes the computer needs to do a relearn. That will also cause an erratic idle. 1 Share this post Link to post Share on other sites
codyhuntsaz Report post Posted August 1, 2020 11 hours ago, Lucafu1 said: I hope you used motorcraft plugs or something good (not autolites). Anyways there is a vacuum line in the back of the intake that slips off or comes apart. I would look there. I did use motor craft plugs. Share this post Link to post Share on other sites
codyhuntsaz Report post Posted August 1, 2020 10 hours ago, Beaton said: Also if you cleaned the throttle body sometimes the computer needs to do a relearn. That will also cause an erratic idle. I read about that too, after I cleaned it the rough idle went down by about 70%. I’ve put about 300 miles on it since cleaning the throttle body. Share this post Link to post Share on other sites
codyhuntsaz Report post Posted August 1, 2020 11 hours ago, ctracingraptor said: I’ll fix it for you but I’m really far away... If you think you can fix it I can bring the truck to you, how far is real far? Share this post Link to post Share on other sites
ctracingraptor Report post Posted August 1, 2020 Peoria Share this post Link to post Share on other sites
