Hooked up the high idle using a Pot. Everything works exactly as it should when the truck is already running and I flip the switch to turn on the high idle. Problem I have is when I use the remote start. I have constant power to my upfitters so the SEIC will work using the remote start as long as the e brake is on and the upfitter is flipped on.

Problem is, the engine is "surging" for lack of better terms and continues to slightly surge until I put the key in the ignition and turn it on. The second I turn the key, the surge stops. The tach, or any other gauge, isn't operational until the key is turned on so I can't tell exactly how many rpms the engine is fluctuating. Sounds like 100 rpm or less, might not even be 50 rpm. It's kinda hard to tell by just listening to it. It's a very slight "surge" but it's noticeable.

Is this normal? The truck was cold (40°) from setting in the garage all night but I wouldn't think that's near cold enough to cause any problems and since it stops as soon as I turn the key I think something else is to blame.

Anyone else experience this? Any suggestions?

Thanks guys.

 

I wonder if your potentiometer is modulating the voltage a bit. It would be an easy test to swap it with a specific resistor and see if the surging continues.

 

Measure the 5V reference under remote start conditions and see if it is stable. The 5V reference is regulated and should be rock solid and not varying. And it should not change when you put in the key.

 

Considering your trying to use SEIC in a manner for which it was not designed, i.e. remote starting a cold truck with SEIC on, that SEIC and the PCM are fighting each other for control on where the RPM's should be at startup based on the temps. You would be much better off letting the PCM's built in cold weather start-up/idle strategy handle those needs.

 

I do agree with your statement but the built in high idle on this engine sucks. The temp has to be in the low single digits for the computer to raise the idle. At 20-30° the truck should idle up some at least. My 6.0 did anyhow. The remote start is pretty much pointless if I have to go out to the truck and turn the key on to raise the idle. Might as well just start the truck with the key in the first place. A 600 rpm idle when it's 20° outside is a waste of fuel and possible wet stacking. Even 20 mins of this wouldn't create much, if any heat. Seems ford doesn't have it all figured out with the 6.7.

I guess a better question would be - Is it going to hurt anything to let it run on SEIC with remote start when it's cold and "surging" slightly? Maybe I should let it run a bit and see if the surge goes away. I only let it run for 30 secs, maybe 1 min before turning the key on. Guess it's an experiment for tomorrow morning if nothing else.

 

I can try but turning the key on shouldn't change what the pot is doing. Never know though.

Care to elaborate further on this please?

 

Low single digits? Thats not right. 32 is the magic number and unlike the 6.0L which has a fixed RPM increase, the 6.7L is variable.

The cold idle kicker strategy provides an increase in idle speed during cold engine warm up. The PCM uses the EOT sensor input and adjusts the RPM accordingly, to a maximum of 1,175 RPM.

I would be more concerned about the engine going from 0 RPM to say 1000, 1200 or what ever you have your POT set at with out first giving the oil a chance to start moving around rather then the slight surge you are experiencing. It would be pretty much the same idea why the 6.7L also has a built in "extreme" cold weather starting strategy that will not allow the RPM to exceed 600ish RPM's for the first 30 seconds by locking out accelerator pedal control.

Overall the 6.7L is far more advanced then the 6.0L when it comes to dealing with cold weather (i.e. getting things up to temp as quickly and safely as possible, preventing wet stacking, etc.) and I do not think the 6.0L does all that bad of a job...

Honestly I am suprised that SEIC works at all with remote start as any such requests should be locked out till the point that you start the truck with a key.

 

In my experience during cold starting the 6.7L, it does automatically rev up almost to 1200RPM (and probably the 1175RPM number mentioned above) eliminating the need for me to manually enable SEIC functionality. In this case the rough running and engine speed instability is due to the cold and probably not from any electronic components I have added, and it goes away after a few minutes of running.

My thought about the 5 volt PTO-REF White/Brown wire is to see if we can rule out the voltage divider circuit being used to supply a voltage to the PCM which it uses (probably with an analog digital converter of some sort) to determine engine RPM during SEIC operation.
If the voltages are varying at the input to the PTO-RPM Green wire, then it would make sense that the engine speeds are varying.
If PTO-REF is at a solid, unvarying 5.00 volts, then check the PTO-RPM line to see if it is the right voltage for the desired speed (per Q180A). Are the voltages changing along with engine speed then?
Electromechanical things like potentiometers are affected by the weather, particularly cold weather. If you've used one in an audio circuit it may sound 'scratchy' when it's cold and the wiper is not properly contacting the resistive area. So this test is to determine if it's doing that due to the component you have added, or if it is not related.
I can't really suggest a cause until I have enough data to look at.

This is what you should see when measuring PTO-REF:

 

Test while running? High idle on?

 

I am not sure about the 32 degree "magic #" because my truck definatley does not go to a higher idle at say 30 degrees. we have not had a cold enough day yet to find out what temp it makes it start a high idle. I have hooked up the high idle mod to my upfitter switches and I still can not get it to go to a high idle.

 

Should have 5V at all times the PCM is on. What we're interested in is what value you get when when you use the remote start, which is with electronics "half-running" as you say.

 

The coldest it's been here so far was 22°F and the truck didn't raise the idle speed on it's own. I left it there for over 5 mins and still the idle speed wasn't elevated. Most guys I've talked with say single digits to get the PCM to elevate the idle.

I used a Pot for the SEIC and it works perfectly. Very easy install and finding the wires was simple. Took all of 5 mins to complete.

Thanks, I'll check today.

 

[QUOTE=Andrew010;11075089]The coldest it's been here so far was 22°F and the truck didn't raise the idle speed on it's own. I left it there for over 5 mins and still the idle speed wasn't elevated. Most guys I've talked with say single digits to get the PCM to elevate the idle.

I used a Pot for the SEIC and it works perfectly. Very easy install and finding the wires was simple. Took all of 5 mins to complete.


I have wired it several times but it will not work. I have not figured out why but I tried it with the potentiometer and just the resistor and it will not work either way.

 

Just checking but did you have your parking brake set? I think it has to be set to go into this mode.

 

The engine contains a unique “cold weather - idle up feature”
calibration strategy within the PCM. Under the appropriate conditions,
the strategy will automatically elevate the engine idle speed after
130 seconds of idling in cold ambient temperatures. For this feature to
be activated, the truck must be in P (Park) with the parking brake
applied and engine oil temperature below 158°F (70°C).