High idle when driving?

[JMBryant]

I've been having the same problem on my 03 for 6 or 8 months myself with the high idle. Some times you will pull up to a red light and it will just not idle down and I cant remember exactly but I dont belive that the brake cancels it. I ve tried letting out on the clutch slowly and it doesnt work either. Some one mentioned the lift pump, but I dont see how that could have any thing to do with the idle on mine as I removed it and have the Walbro set up on mine. Any one come up with anything yet???

 

[BGarofalo]

My 03 6speed will do the same thing. Every once in a while it will stay at 1000 rpm. Once the motor warms up a bit it dosent happen any more. I didnt think it was a big deal. My guess is its just a computer issue. I have noticed it is on particularly cold days that this happens though.

 

[DPKetchum]

What you described is basicly how its suppose to operate. Thats auto high idle and they ALL do that. Its not suppose to stay at 1000 rpm under motion or once engine temp is normal. If its cold enough and say a LONG redlight it may very well jump to a 1000 rpm because of loss of engine heat etc. But its NOT suppose to do 1000 rpm coming to a stop or backing etc.

 

[daytripper63]

Come on everyone

Any ideas on this plus a rougher than stock idle?

It does not idle like a miss just not like it has been the previous 5 yrs

 

[JHardwick]

I hate to tell you this, but I replaced several parts when mine did this. Ryan Battelle helped on this one.



Mine would idle up like that on a 90* day after a 30 minute cruise. Dragging the clutch, or trying to push the brake pedal to the floor were the only two ways to get it to idle back down. The only thing that cured the problem was sending the injectors to DonM.

 

[stick]

I do feel like I have been developing an injector problem, I just can't understand why pushing the brake brings the RPM down. But there is alot of things in this world that i'm not quite sure about.



Stick

 

[JHardwick]

I do feel like I have been developing an injector problem, I just can't understand why pushing the brake brings the RPM down. But there is alot of things in this world that i'm not quite sure about.



Stick

When you drag the clutch at a stop, you load the motor through the crank. When you use extreme brake pressure you load the motor through the power steering pump.



Why does this slight loading of the engine settle the RPM back down? That I don't know, but mine did this for well over 100,000 miles. Sometimes with slight injector rattle and sometimes not.

 

[GaryOwen]

Like I posted earlier, installing Smarty Jr cured mine. Still working fine, but haven't gone back to stock setting to see if problem arises again.



Might check IAT relay connection. I have knocked mine loose a couple of times when changing oil.



Gary

 

[JHardwick]

Like I posted earlier, installing Smarty Jr cured mine. Still working fine, but haven't gone back to stock setting to see if problem arises again.

Might check IAT relay connection. I have knocked mine loose a couple of times when changing oil.

Gary

I think it has more to do with injectors dribbling, causing poor atomization and cold idle. The Smarty increases rail pressure which helps atomization.

Check this ... ... ... ... .....

With stock injectors, I'd pull into a truck stop to sleep for a 3-4 hours and wake up with 160* water temp in the winter.

With my F1 injectors it never drops below 180* with a 3-5 hour idle in winter.

Mine did it with the Edge EZ, the Quad Race and with no box. The Smarty may mask the problem, but I think it's and injector issue at heart.

I bought this truck with 14 miles on it, now with 400,000 miles, I know it's quirks, but may not have all the answers.

 

[JHardwick]

Might check IAT relay connection. I have knocked mine loose a couple of times when changing oil.



Gary

That throws a code.

 

[GaryOwen]

I think it has more to do with injectors dribbling, causing poor atomization and cold idle. The Smarty increases rail pressure which helps atomization.

Didn't think about increased rail pressure w/SJ - makes sense. You're right that the IAT sensor would throw a code too.



Guess I am still learning all the quirks - still need 29k mi to reach 400k.



Gary

 

[DE Jeeper]

Mine has high idled before and after my flux injectors. Still not sure what it is, but I am getting my Smarty sooon and I'll let you know if that fixes it.



Aaron

 

[jman]

Would a CPS that was out of spec cause this. I had my injectors rebuilt and it still sticks at times. Just thinking that the CPS maybe sees a different rpm and tells the ECM it needs more fuel. Mine has done this for so long it doesn't even phase me anymore. It would be nice to fix it, but I refuse to give myself brain damage over it.

 

[DE Jeeper]

If the cps was bad your fueling timing would be off relative to the cam and crank. It wouldn't think the motor was going faster. I think it is a programing glitch with the ECM and/or a bad sensor that no one has found yet. If the Smarty fixes it it would seem to confirm a ecm programing issue.



Aaron

 

[jman]

It is more of an annoyance than anything. It must not be anything to major or we would be having problems. Mine has been doing it for nearly 40K miles and others just as long or longer. I'm sure a fix will turn up soon, especially with the number of people having this issue.

 

[scottmcd]

I too have this same problem. Happened with my Banks, and still happens with the Edge Juice. Still did it after my lift pump conversion. Only way I can get it idle down is to let out the clutch alittle and it drops to 750 rpm. It is more annoying than anything. It happens no matter what the Edge is set on!



Scott

 

[JHardwick]

I'm just saying that the only thing to fix mine was the injectors.

 

[betterthanstock]

If the APPS (throttle sensor) is getting old, maybe it needs recalibrated.

Disconnect batteries for 10 minutes or longer.

Reconnect batteries. Turn ignition on without cranking. Let it stay on for at least 10 seconds.

Slowly push the throttle all the way. Let go.

Start engine.



Let us know if it fixes it.

 

[Marco]

This sounds to me like... . I would look into the ground circuit of the APPS.
If the ground is bad than the reference signal is "lost" and the engine idles right arround 1K. That's been the poor man high idle on my 99 for a long time.
I've wired in a switch that opens the ground wire of the APPS voilà, high idle...

Marco

 

[DE Jeeper]

If the APPS (throttle sensor) is getting old, maybe it needs recalibrated.

Disconnect batteries for 10 minutes or longer.

Reconnect batteries. Turn ignition on without cranking. Let it stay on for at least 10 seconds.

Slowly push the throttle all the way. Let go.

Start engine.



Let us know if it fixes it.

Preety much did this when installing the twins a few weeks ago. I had the bats disco'ed for 2 days and cranked it for several times for more then 10 seconds to prime the turbos and it didn't fix my high idle. It could be the APPS ground. I have had to mess around with the mount and wiring several times when changing vacuum pumps and installing the FASS. When it warms up a bit I will check the harness.



Aaron