Off idle hesitation

GaryB · Aug 19, 2019

Once in a while, I'll get a hesitation at a stop sign. It will hesitate and then go. Not sure what could cause this. Do you have any suggestions on where to start? I cleaned my MAF and installed a new Air Filter 2 weeks ago. Thinking of cleaning the throttle body.

1955moose · Aug 19, 2019

Since you posted in 3rd gen section, I'm assuming it's a 2007-14 Expedition. If you could post the year and model, it would help. As always, our recommend jump-off point, is check for any stored trouble codes, and then do a fuel pressure test. The fact that it's intermittent, rules out tune related, ie spark plugs, boots, etc. Third editions have problems with failing throttle bodies, you might look into that. Intermittent problems can be tough, report your or mechanics findings.

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GaryB · Aug 19, 2019

Sorry, I thought it was in my signature....it's a 2010 expy limited. no stored codes. according to mode 6 on my OBDLink App, only 3 misfires in cyl 4. (I assume that's good?) 1 misfire in Cyl 1.

Adieu · Aug 19, 2019

Replace #4 plug, coil, and injector maybe?

Maybe even just the plug... mechanics getting lazy and not touching the rear two plugs (#4 & 8) is a common thing

1955moose · Aug 19, 2019

Well there you go. Misfires on these motors can be anything as simple as a spark plug or coil, all the way to cylinder head problems. I'm with Adieu, start with the components of #4 first. He's right about mechanics skipping the back 2 plugs due to difficulty of changing. Sometimes setting a code isn't always easy. Glad your scanner picked up the misfires.

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GaryB · Aug 19, 2019

Ok great. I'll start with plugs and coils. Are the aftermarket coils any good? Amazon has some that have high reviews for 8 that are less money than 1 motor craft at autozone.

bloodhound · Aug 19, 2019

GaryB said:
Ok great. I'll start with plugs and coils. Are the aftermarket coils any good? Amazon has some that have high reviews for 8 that are less money than 1 motor craft at autozone.

I got a set of Accel coils which it seems no one here is a fan of, but I put about 60,000 miles on them with zero issues.

GaryB · Aug 24, 2019

Thanks Blood hound. I ended up with Bravex coils off amazon. For $65 for a set of eight, I figured it was worth a shot. Installed all 8 today with fresh motorcraft plugs. She runs like a spotted ape now, with no hesitation. It's amazing how much it improved the lower end (1500-3000) Hope it stays that way. I'll update if it doesn't.

On the other hand, I think I have a mild valve gasket leak. Noticed it on the plug wells, and on the porcelain of #2. Another sidebar, I bought one of the cheap wifi borescopes off of amazon for 25 bucks. Very need to be able to stick that down in and look at each cylinder. Noticed much more carbon than I would have thought after only 30k on a Jasper rebuild. Does anyone use seafoam or similar in these trucks?

Adieu · Aug 24, 2019

Seafoam is OK

Did you notice if the idle while stopped in Drive was lower before the coil change or not?

GaryB · Aug 24, 2019

I think it is idling lower. My scan tool was showing the idle around 630 before...I haven't hooked it up since, but the dash was showing 500 at a hot idle.

Off idle hesitation

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