High idle and hazing.....

[Tom S]

Thanks Dave!

 

[SeeYa]

Easy now, I'm just reporting symptoms, I'm haven't figured anything out yet. I'm not sure if I can control my truck with my mind, but I'll give it a shot.




As of the other morning, it was a warmer temperature outside at around 45 degrees, and it decided to kick up into high idle. So at the moment, I don't seem to have any symptoms even with the chip reinstalled. I'm sure the gremlins will come back though. About the throttle going dead while driving, Im not sure if its related to the lack of high idle and hazing or not, thats kinda why I asked for advice on here. It only happened on two seperate days, both times were when my chip was installed. The first time it happened, it went dead every time I let off the throttle completely in the stretch of about 15 miles, probably a total of 5-7 times. Once the motor warmed up, it didn't do it the rest of the trip. I think part of the problem is that the truck doesn't get driven a lot. Its lucky to get 5,000 miles on it per year.

There we go now we are getting somewhere. And for being sa but electrical or wiring issues are the hardest to tap down. This being intermittent sure sounds like what I've thought it could be. Check the wiring to the EOT sensor or it could just be flaking out.
Nice table shots, but they are not the ones I was talking about.

Thanks though.

 

[jngreen]

Easy, hell. You said it does it regardless of whether the pcm has any programming plugged into it or not. Then shortly after that stated it doesnt do it on stock programming. Thats why the comment was made. You'll have to determine when it does really do it before anyone can figure out whats what. And id expedite getting rid of that superchit tuning.

Two seperate issues bud, well actually three. Go back and reread what I wrote. The engine not going into high idle and hazing when cold happens on any programming, with chip, with hypertech tuning instead of chip, and bone stock programming.

The dead pedal and check engine light happens sometimes when the engine is cold, and only when running the chip. It got so bad at one point that I pulled over, turned the truck off, and pulled the chip out. With the chip out, on the stock programming, the pedal never went dead again.

I don't know if these three issues are related or not, thats why I started this thread. Also, who cares if I have a hypertech programmer? It came with the truck when I bought it, and I don't use it unless I want to see if an issue is caused by my chip. I agree that the tuning is not as good as my chip, but its better than stock and I keep it under the back seat, just incase.

 

[Tom S]

Did all your problems kinda start at the same time?

 

[907DAVE]

Nice table shots, but they are not the ones I was talking about.

Thanks though.

But they are the ones that control the cold idle....

Not sure what you else you had in mind when you said EOT controls it.

 

[jngreen]

yes, thats why I thought they were all related, although it seems it was perfectly fine the last time I drove it.

 

[SeeYa]

This is what Jody gave me. DAve, If you need to see your tables likes these all you need to do is press F6.




This one shows in second the time which it takes for hi-idle to engage without your foot the on break and it meets the temperature conditons.



This is the cold idle adder showing the amount of idle rise based off of EOT in celcius. Roughy 200 rpm.



This shows the relation of the EOT sensor to idle speed.


I'll leave y'all to discuss this. It's Friday and our oldest is due back from a school trip he's been on for 3 days. I won't be back on here until Monday.

Interesting stuff and yes jngreen we still need you to read the code you are getting. Did you do that with the Evolution? I didn't read back so I can't remember if you did or not. It will help tremendously.

 

[TyCorr]

yes, thats why I thought they were all related, although it seems it was perfectly fine the last time I drove it.

w/o high idle id think you would get haze. Low egts cause my shti to haze,when the high idle kicks in egts go from 325deg to 500+(no ebpv) and the haze/smoke disappears also. Does it haze if its warmed up but idling? Also, since you've got low mileage you may never have lived through aging inj orings which when they start going do exactly what you're describing.

I didnt mean to jump your shti, for that I apologize.

P.S. ive only two friends who still run 7.3s. One is a 2k that is bone stock save for gauges and 5" exhaust. He used to run an evolution butgave it to his dad for their cattle trailer truck(01 450 psd 6spd got for free from pioneer for buying 26k worth of seed. Sweet deal, eh). His truck is still tight but gets horrible fuel economy. Another friend has an e99 that has similar mileage. Both of those guys are at 100k. Im at 250+ and my truck runs better all the way around. So I can sympathize with what you said abiut your family members well running but rusty psd in comparison to your low miled troublemaker.

Good luck bud!!

 

[907DAVE]

This is what Jody gave me. DAve, If you need to see your tables likes these all you need to do is press F6.

Yeah....I know how to change views.

I posted them that way because most people need some type of visual to help them understand better.

Now then, show me how EOT has anything to do with the high idle function on a cold engine. We all see how RPM can vary with EOT (very slightly, and hardly enough to notice unless you are in extreme cold), but that is not the complaint here.

 

[SeeYa]

Yeah....I know how to change views.

I posted them that way because most people need some type of visual to help them understand better.

Now then, show me how EOT has anything to do with the high idle function on a cold engine. We all see how RPM can vary with EOT (very slightly, and hardly enough to notice unless you are in extreme cold), but that is not the complaint here.

Dave, I am not a tuner and Jody has explained the process to me and it makes perfect sense. I'm not saying this is the op's issue, but based off of what he is describing an EOT sensor issue is a high possibilty.

Jody uses the bouncing ball feature with his software and it will highlight the active area. If you could see what he has shown me all that I posted will make better sense to you.

Please feel free to email Jody over the weekend if you have anymore questions.


Diane

 

[strokin'_tatsch]

Those functions add to the idle speed. The 1st is the time it takes to add in the cold idle control, 2nd is the RPM that will be added vs IAT, and the 4th is RPM that will be added vs EOT. The only thing that will disable the cold idle control is your brake pedal and a EOT parameter that will turn it off after the preset temp is reached. The EOT vs RPM (#4) will always be there, regardless of what you are doing with the truck.

Also keep in mind this is all in Celsius.

You are just reading under hood temps instead of intake air temp....which for most aftermarket intakes is the same thing.....lol.

So what effect would unplugging the IAT sensor have on how the engine runs? After seeing some of this, I think I might have a couple problems that could be due to an MIA IAT sensor. I never unplugged it, but I noticed it was gone a few months ago.. Just never thought it effected much.

 

[907DAVE]

Dave, I am not a tuner and Jody has explained the process to me and it makes perfect sense.

Then whats the problem now?

Jody uses the bouncing ball feature with his software and it will highlight the active area.

So somehow the bouncing ball changes PCM function?

If you could see what he has shown me all that I posted will make better sense to you.

It makes perfect sense to me, I think you are the one having the issues understanding these basic PCM functions.

Where in the functions do you see anything that has to do with cold idle control (auto high idle) and EOT??? I agree EOT will kick it out of high idle around 160* Fahrenheit, and possibly add a few hundred RPM to the base idle when temps drop below -10* Fahrenheit....but otherwise it has no relation.

So what effect would unplugging the IAT sensor have on how the engine runs? After seeing some of this, I think I might have a couple problems that could be due to an MIA IAT sensor. I never unplugged it, but I noticed it was gone a few months ago.. Just never thought it effected much.

Not much really, unless you live in a cold climate I doubt you would ever notice anything. The PCM will default to 15* Celsius with the sensor unplugged any carry on with its usual tasks.

 

[TyCorr]

Thanks for the info on the iat.

 

[jngreen]

w/o high idle id think you would get haze. Low egts cause my shti to haze,when the high idle kicks in egts go from 325deg to 500+(no ebpv) and the haze/smoke disappears also. Does it haze if its warmed up but idling? Also, since you've got low mileage you may never have lived through aging inj orings which when they start going do exactly what you're describing.

I didnt mean to jump your shti, for that I apologize.

P.S. ive only two friends who still run 7.3s. One is a 2k that is bone stock save for gauges and 5" exhaust. He used to run an evolution butgave it to his dad for their cattle trailer truck(01 450 psd 6spd got for free from pioneer for buying 26k worth of seed. Sweet deal, eh). His truck is still tight but gets horrible fuel economy. Another friend has an e99 that has similar mileage. Both of those guys are at 100k. Im at 250+ and my truck runs better all the way around. So I can sympathize with what you said abiut your family members well running but rusty psd in comparison to your low miled troublemaker.

Good luck bud!!

Thanks for your support. I don't consider my 80,000 mile truck to be a trouble maker though, it starts everytime I want it to and does everything I ask it to. It has never failed me, not even a cps in the 6 years I've owned it.

I just happened to notice a few strange things going on, so I asked some questions. The issue with the dead throttle kinda sorta concerned me, but it seems to have worked itself out for now. I was kinda hoping it was all related to my chip, so I could replace it and move on, but it doesn't look like I'm that lucky because its now running perfect again with my chip installed.

I think my truck is just begging me to drive it more often.

 

[jngreen]

Also, just wanted to say thanks for everyone sharing info. I'm still learning.

 

[TyCorr]

Thanks for your support. I don't consider my 80,000 mile truck to be a trouble maker though, it starts everytime I want it to and does everything I ask it to. It has never failed me, not even a cps in the 6 years I've owned it.

I just happened to notice a few strange things going on, so I asked some questions. The issue with the dead throttle kinda sorta concerned me, but it seems to have worked itself out for now. I was kinda hoping it was all related to my chip, so I could replace it and move on, but it doesn't look like I'm that lucky because its now running perfect again with my chip installed.

I think my truck is just begging me to drive it more often.

That pedal issue would concern me as well.

 

[4.0l sahara]

A little off topic but is the pcm using the iat sensor by the filter or the one in the valley or both?