hello all .....

I'm wondering if it's worthwhile to get my van's PCM reflashed.
( I didn't see any other posts here on FTE about reflashing a van's computer. )

I'd also like for it to idle a little faster, up from 650rpm to about 850rpm.
1. When doing boondocking camping (no shore power or water hookups) at times I need to let the engine idle for about 30 minutes to charge up the 3 "house" batteries.
2. I also need to let it idle at times, with the vehicle's ac on.

Letting the vehicle's engine do these tasks, has been less expensive than carrying/fueling/maintaining a small generator.

The engine's 650rpm idle in neutral, is too slow to do these tasks well.

2004 E150 XLT, 5.4L, 3.55 diff, LT245/75R16E BFG KO2 tires, 130amp alternator, 160k miles, drivetrain bone stock as far as I know.
The van is carrying a fair amount of weight, being a camper with 3 house batteries, 14 gallons of fresh water, and a lot of tools & van-camping items.

I drive it like a granny, still only 9-11mpg's around town, maybe 15 on the road at a steady 67mph (freeway right lane truck speed).
When I calculate mpg's, I do take into account the oversize tires, keep tire pressures at about 55psi.

It starts, accelerates, drives, idles really well .. never misses a beat.
Mechanic tells me the brakes aren't dragging.
Spark plugs were changed by an experienced mechanic, at about 120,000 mi.

I bought it used in 2008, at 92,000 miles, from what I could tell it was mainly used on the highway, carrying passengers.
Carfax didn't show any evidence of servicing at a dealer, as I remember.

I've never taken the van to a dealer for anything.

I'm wondering if reflashing is a good idea. I'd hate to mess up a good running van.
Reading posts on here about reflashing other Ford vehicles, it's looking like some dealers are knowledgeable about reflashing, and some aren't.

And it's looking like some shops are knowledgeable about reflashing and can do it.

I'm wondering if I should just let a sleeping dog lie, or get the PCM reflashed with any benefits that has to offer.
And wondering if there's a good way to increase the idle RPM's.

thx, Ed

 

Unless there is a service bulletin about your model and year pertaining to performing a flash of the computer directly from Ford, and if its running well with routine maintenence I would not do it.

 

Agree 100% here ^^^.

You might visit this site: SMB Its geared towards RV-type conversions, the users there dealing with recharging house batteries.

You're looking to change parts of the PCM's strategies that either isn't advisable or perhaps possible with adversely affecting other aspects of how it controls the drivetrain. You could also look into some sort of device that is selectively engaged to raise idle speed as needed wanted. I can't steer you in any one direction but something probably exists somewhere.

Best of luck with this!

 

A custom PCM flash/tune should be able to do that for you.
An OEM/dealer flash will not.

Might be a PITA during regular driving though.

Maybe an aux throttle cable instead?

Might have to get creative with the connection to not interfere with regular throttle ops.

Looks like a cable would be about 1/10 the cost of a custom flash.

 

thanks, jbwheels, jwa, and nicksan for your replies,

The swb link took me to sportsmobile forums, and I love Sportsmobile van camper conversions.
And thx for the link to the aux cable on Amazon.
That cable seems like a possibility.

I have to admit that regarding the reflash ... not fixing what's not broken, is looking like a good idea.
I'll check to see if there are any service bulletins that recommend a reflash.

Faster idle wise ... I did try a modification that kept a little tension on the throttle cable, speeding up the idle.
Since it was a pain to adjust, I let it be in "speedup" mode even while driving ... idle speed about 900 rpm's.
Driving while in this mode, engine braking all but vanished, needed to use brakes more often .. this was a PITA.
And each time I started the engine, the idle speed was different .. so that idea wasn't a good solution.

Thought about creating a vacuum leak, using some kind of inline 1/4 turn valve, but dropped that idea,
figuring the IAC would keep the idle speed at the normal 650 rpm's, and I might still have the driveability PITA's.

nicksan wrote " some sort of device that is selectively engaged to raise idle speed as needed"
That does seem like a good solution, a device that's engaged after engine start, when fast idle is temporarily needed, then disengaged after the battery charging task is done.

And I'll search online for such a device, hopefully something simple shows up.
And maybe the smb forum, or other van camping site, will have a good idea about creating temporary fast-idle.

 

That's what I would do. There is an idle adjustment screw on the TB I believe that can bump the idle up, but that would be hard on the transmission slamming it into gear at a higher rpm all the time.

 

thanks baddad,

I'll look into the idle adjustment screw.
And also look into actually getting at the throttle body .. what to remove and how, to get in there.
Sounds like I need to experiment with idle speeds a little, to avoid it slamming into gear.

 

You'll first need to remove the air cleaner box. Pretty simple, all you need is a 1/4" drive 5/16"socket & ratchet to remove the 4 bolts and loosen the hose clamp on the intake hose coming off it. Takes me all of two minutes to do mine. Plus I removed the silencer from the air box long long ago. (plastic part that attaches to the air box inlet)

 

Thanks again, baddad,
I'm looking forward to seeing if this works.