Ive done alot of searching for this, but nothing I find really fits the description..

This started while taking a weekend trip up North... Approx 600 miles round trip.

While driving, running temp, at cruising speeds in OD (or drive) the engine feels like its hesitating. Studders and luggs... This happens without fail at the RPM range of 1500 to 2000. Just before the tranny shifts down to gain speed. When it shifts it'll go away.... than when I'm cruising in the final gear, it'll start hesitating.. if I hold the RPMs it will continue... if I add accelleration it'll shift and go away.

I want to note that I calculated our MPGs during this trip..... I was shocked to see 9 mpgs in town, and a whopping 12 on the freeway. I know these 5.4s are thirsty but I can't believe this is normal running MPG

Towards the end of our trip I had a decent hill to climp over. Ater climbing this hill and making it to the other side, the hesitation worsened to the entire RPM range. Didn't matter what gear or speed. Any, and I say any kind of hill, the truck would struggle to get over. 30mph max at full throttle and it shook and spuddered. Once on flat or a downhill slop, the truck would move forward, but with massive hesitation.

Sounds like something easy..... but whats confusing me is that in park the truck runs and idles smooth as silk. Accelaration through the RPM range is smooth as can be... However when I first turn it on the Idle rises very high and slowly drops down. Goose the gas, it will rise to about 3k rpms and drop real slowly.

I've racked my brain over this and just made myself tired. Anyone got any ideas or suggestions?

There are NO codes or check engine light.

Any info would be greatly appreciated

Cheers

nem

 

Most likely a bad coil, -it's almost a guarantee lol.

To generate a DTC, find the specific load which will be, @45-50 mph and right after the shift into OD under normal acceleration. Hold it there. This will increase the misfire monitor count to the point of a CEL (MIL).

If that doesn't work, accelerate up to speed as described, hold @ misfire load temporarily and then push the motor, coast back down, hold @ misfire load and push again.

If that fails to generate a DTC, -it's best to just change all the coils as far as cost for the alternative.

Purchase only Visteon/Motorcraft replacement coils found on eBay and Amazon sites as purchasing Motorcraft via dealership or third party isn't very cost effective. Visteons derive from their Hungary plant and are made with the same Ford spec as the motorcraft brand in singularity.

Follow these instructions and you'll save time and money.

 

Thanks Jbrew for the feedback,

The truck drove this way for 15 miles without throwing a code or CEL..

While I don't mind replacing all the coils, I just prefer to be certian my money is going into the right direction.

As for forcing a code... those last 15 miles made me wonder if I'd make it home.. not sure driving it is a good idea. Also you would think that alone would have thrown a code?

I have a feeling that tomorrow it'll run just fine... making this an even bigger PITA.

Did a quick look on ebay... found a bunch of sites selling the Coils... just not sure which? Quoted at Napa they are 65$ a piece... ebay 65$ for a set of 8. Not exactly sure which is the right way to go?

 

No Problem
Have you noticed it blinking, then shutting off? How do you know that you don't have a DTC logged in the KAM? The CEL(MIL) need not be lit up to have a DTC stored pointing you in the right direction. In case your unaware. Scan it free @ Auto Zone.

CEL= CheckEngineLight
MIL= MalfunctionIndicatorLamp
DTC= DiagnosticTroubleCode
KAM= KeepAliveMemory

I know, that's the purpose for all information posted above. A diagnostic run is $100 alone. Keep that in mind when weighing it out. To have a dealership complete the work will be roughly $300 for just one coil replacement. Your most likley at the point where the coils may start to fail, like domino's.
Yea, as said, scan it anyway. If you find the culprit, then you can replace just that one. But if the vehicle ran like a slug when firing on all 8, it's time to replace the coils. Like I said, just use the name I gave you, -you haden't last time. "Visteon". No other.
Well, if that's the case, it's getting wet. Boots get bad to, still , at this stage, the coils are due.
Forget all that and go with the best, NO reported failures. Info posted is from experience, so read it carefully. It will pay off.

I'll post your coils for yuh, -

http://www.ebay.com/itm/New-Visteon-...5bc1a1&vxp=mtr

These and Motorcraft are constructed using the same specifications. ONLY these. Don't trust any other.

Change them all out at once, since ignition integrity plays a large roll with performance and the truck may just feel like it lost 1000 lbs or so. You can get away cheap using the best and properly installing. Get those mpg's back as well, -IF your O2's are healthy.

Now that I post all that, - this should have been first. Check your fuel system as sort of a precursor to everything mentioned. That's the first thing you do troubleshooting this one. If you don't have a fuel pressure tester, borrow one from Auto Zone if they have a free loaner program. Most of them do. It doesn't sound like a fuel delivery issue, but it could be. If pressure is low, or marginal, replace the filter and give it another go.

Are you in California ? If so, I've heard the Auto Zone suppliers work a little differently there. Just in Cali, nowhere else lol. I don't know to what extent, but they may not offer the same services as they do in the rest of the US. You may have to determine that one on your own if nobody else posts up.

 

Forgot to mention in my earlier post... or thought of it and didn't type.... Used a Scan tool from Napa Auto.. came back with Zero Codes. I'll do it agian tomorrow just to be safe.

thanks for the wealth of knowledge. I agree, with its age and milage, (84K) new plugs and Coils certianly couldn't hurt.

Again, thanks alot for the info posted. I now have a direction to go in that best fits the issue.

Thanks for the link as well.. that item seems more like it.

Cheers

Nem

 

Replaced the Fuel filter already. In my experience.. mostly with older Fords, any hesitation was fuel or ignition related. So I dove right in with a filter.

Also want to through out there that I removed the Trottle body and thoroughly cleaned it. Inside the butterfly was black and "gooey"... also cleaned the Intake Plenum the best I could without taking it off.... may do that since I'm gonna be there anyway.

With that being said, should I consider the EGR valve as part of this? The TB wasn't the cleanest....

Auto Zone will rent you the item, at the full cost of buying it... you return it they will refund you. So its free as long as you don't decided to keep it.

 

Good, nah, the EGR/EVR would cause problems @ idle. I wouldn't touch those. Check that fuel pressure tho. When getting the check kit from the Zone, make sure it has the "Ford" shrader valve adapter. They should know what you mean.

If doing the plugs, just use these choices, -

Motorcraft (good (NOT Autolite))
Denso Iridiums (best IMO)
NGK (good as well)

84,000 miles, - Your getting close to average fuel pump life expectancy. The factory pump is usually good for 90,000 miles. They usually take a dump around this time. Your O2 sensors should be good to 100,000 miles. If I recall, the absolute lowest reading can be 29 lbs on the pump. You should see low to mid 30's. While you checking that and the with the engine running, locate your fuel pump relay and put your hand on it. They get warm/hot when they're getting flaky. That could be a problem as well.
To locate the relay, - Ford moved these around a lot thru the years, so your little owners manual in the glove box will tell you where that is. No owners manual? Download one @ Motorcraft.com.

 

Thank you again Jbrew,

Sounds like I've get plenty to do.

Cheers

Nem

 

here is an Update:

Got the Coils and new plugs installed. So far so good. My only complaint now is.. since the tune up when in park if you press the gas pedal just barely it will idle real high and take a while to come down to proper idlle speed.

My first thought is a vacuum leak... something I bumped while doing the tune up maybe? I looked all around and couldnt find any obvious culprits.

Any ideas?

Otherwise thank you very much for you help and direction Jbrew. It is much appreciated

Cheers

Nemi

 

Good job. That's normal, - it'll quit doing that once it adapts. Your AF's are in adaptive strategy mode at the moment. From the battery disconnect.

 

If you continue having idle issues, the IAC may be dirty and sticking.

 

glc,

The high idle started directly after I cleaned the Throttle Body last weekend. I am guess this has something to do with it.

Gonna go check out the IAC.

Thanks bud
Cheers

Nem

 

Yea, you can ruin a lot of stuff on the throttle body if you used any chemicals. The IAC, TPS and EGR diaphragm if your not careful.

 

I completely removed the TB when I cleaned it.. and only used Throttle Body Cleaner that was advertised sensor safe. I suppose that doesn't mean much in the end....

 

Well, you should be alright then. As long as you didn't shoot the TPS point blank. You can burn the ribbon, it uses film ribbon, like tape with wires. Very thin and loosely coiled inside the sensor housing. So you may get an idea how it may be compromised.

You can clean the EGR valve, but just the valve and NO compressed air or chemical should pass the valve as this would compromise the more delicate diaphragm.

You can clean the IAC, but there's a somewhat strict method to do this as well. I would say, but I gotta go lol.