Please throw a dog a bone! I have a 99 V10 w/112K miles (F550 rollback) recently had serviced w/ steam clean and hasn't run the same since! It misses at idle stumbles badley on initial acceleration.The scanner shows no current codes and only a pending code of a lean condition. I have checked for vac leaks and found none. The engine stalls when we play w/ the mass airflow sensor wiring coming form the air cleaner housing but the wires from the chassis connector to the sensor are all in good shape. There are no missfire codes but it feels like a dead coil- wouldn't it show on the scanner as a specific coil # missfire? any help would be apperciated. I can't work this truck till this issue is resolved.Mike.

 

lots of compressed air blow things out.
you also may have blown a hole in the pcv vacum tube
You problably have water in the sparkplug holes.
Suggestion pull the cops and blow out the holes with compressed air and change the plugs and boots.

It won't show a misfire code until it reaches a threshold in pcm and so many drive cycles ,certain scanners don't read misfire codes also.
Rich

 

The dreaded "high pressure cleaning" illness...

Like Rich said, many things get sick when that happens. Even though you would think that warming an engine up afterwards should get rid of trapped water in the plug cavities, that's not necessarily the case. It could remain long enough to infect the boots by causing the already junky rubber to deteriorate even more, allowing the charge from the COP to go to ground.

Then there's water in the MAS, in the COP connectors, and other electronic components. And Rich was right about the PCV hose and 90 deg connector - they are made from the same "sweetgum" junk as the COP boots; very easy to damage with high pressure.

 

You have water down the spark plug holes, I'd bet.

Remove all the COPs, blow everything out until it's dry, and reassemble with dialectric grease and possibly new boots.

When were the spark plugs last done?

 

Yep, quit power washin my engine after readin about all the associated problems!
(rather have a dirty healthy V-10 than a clean sick one any day !!!)

 

Thanks for the replies, I just changed the plugs w/ all new boots there was some water in the holes but all got blown out. I checked the PCV valve @ the valve cover and the inner tube is sealed tight. I tried spraying brake cleaner around any vac ports looking for a change in idle but nothing other than the slight miss it already has.It stumbles very badly when accerlerated from a stop and then it cleans up but still feels low on power.My buddy has a 3K snap on tester that I used to do all tests available on the menu and all showed ok.The vac leak was a pending code I think.The MAS and the air temp sensor where both dry,I cleaned the MAS

w/ electrical contact cleaner but no difference.
Can a coil go bad and not throw any codes?

 

What was the code you got ? pxxxx lean bank 1 /bank 2
Chk the pcv valve tube at the elbow, it likes to split and crack.
Did you use stock plugs? These motor don't like aftermarket plugs.Electronics fubars.
That should be a pretty decent scanner then.
This sounds like a vacuum leak now
Rich

 

The V10 can certainly misfire, have a bad MAF, or lots of other things without throwing a code...

Read this:

https://www.ford-trucks.com/forums/5...t-come-on.html

With that fancy-schmancy reader, check the misfire counters. If it points out one specific cylinder with lots of misfires, get a new COP and try it. Or, pull the plug and clean it first...

 

I hit a water puddle about 5 months ago and the truck started running crappy. Found out the coil packs (2) of them went bad. Just had some replaced early last year. This could be your problem. Have never owned a weaker engine when it comes to water.. Also these coil packs are expensive. I am now afraid to drive this truck when it rains. Might hit a water puddle and have the truck back in the shop for another 5-600 dollars.

 

That little splash of water didn't burn out those COPs. They were probably (almost 100% certain) still good. The boot got wet, shorted the spark to ground, and no fire.

I've driven my SD through water deep enough it was almost inside the cab.

Never skipped a beat.