View Full Version : Wonder What could have happened
Ok some of you guys know that I had some new gears installed, when we took the truck to the guy it idled just fine, I went to pick up the truck, and now it has an up and down idle.
Would driving it after the gear change and not re programming it to the proper gear ratio cause this?
I checked what vacuum hoses I could to see if there something wrong there, and I can't find any,
You know how it idles when your AC hasn't been recharged and you turn on the defrost? that what it acts like,
Could use some help again, for I have no idea where to look.
12sws27
10-26-09, 11:25 PM
Check all the connectors on the S/C tubing. IAC sensor (Idle Air Control) could have went bad. Got any DTC's? Sometimes things like that are coincidence. Sometimes crap goes bad because of sitting. I would take the Jammer belt of so it's easier to listen for vacuum leaks and make sure you don't have one before I bought a IAC.
Only thing you would need to have changed in the PCM is the speedo since it'll be off now because of the gears being different. You can do that with the Hand held though.
Yep I did the gear ratio change, I'll check it out tomorrow, I just don't know where to look, check engine light don't come on, so I'm hoping it isn't nothing major.
Dang maybe I should have just left it along, it was running fine till I picked it up tonight.
It's like a vacuum leak, but I'll be darned if I can find it.
Man this is discouraging
12sws27
10-26-09, 11:37 PM
Stop mind fuking yourself...it's not a big deal Ed. Don't stess it. Watch. It'll be either a damn simple leak or the IAC.
Stop mind fuking yourself....
LMAO!!
I'm sure you'll get it figured out Ed...you've done okay with your projects so far...
You guys are beginning to know me so well, lol lol I've got a brand new IAC right here, lol lol well heck I've got the whole TB if need be.
I'm sorry guys, I just get stressed so easy for some reason,I let too many things bother me.
Its really hard for things to be perfect, and I guess I expect things to be that way all the time.
LMAO!!
I'm sure you'll get it figured out Ed...you've done okay with your projects so far...
LOL LOL mind, screwing yourself, lol that is pretty funny ain't it?
I've done pretty well so far, your right, but it sure humbles me, and I'm sure God has had to plug his ears too,..not to mention that these projects beats the crap out of me, but I usually get it done eventually.
Probably should go up and down the alley before it snows, so I can pick the tools that went zinging though.
I don't know guys, got several different scenario's, do you think, or is it possible, that with the gear change, that the speed sensor would send the wrong signal to the computer, and messing with it's mind a little bit?
Also you know where the brake booster hose goes to the intake?,that little hook up thingy on the intake seems pretty free to move.I re-changed the hose, for I goofed that up trying to hook up my boost gauge, for it looked like it was pulling on the check valve.
Then there's the PCV valve, which I don't think has been replaced since it was new,so I replaced that too.
Seems to idle somewhat smoother, not near as erratic.I guess at almost 80,000 miles things are going to start messing with me,for the only thing I have had to replace is the Alt.
I'm a firm believer in preventative maintenance but I don't know the weakest part.I know I should be replacing the O2's here pretty soon,and probably the IAC sensor.
Already replace the TPS because somebody got the bright idea to try and do that TPS Mod, which was a joke.All that did was throw a code,but had good intentions
I'm not sure on the Crank Sensor, or MAF sensor. I know the ole saying goes if it ain't broke, don't fix it.But I don't wanna go broke fixing it either.
But I reckon that is what a code reader is for uh?
I really wanna thank you guys for tolerating me,putting up with all my whining when things don't go right,and most of all for your help,and to the Planet for all of its resources.
Bone Crusher
10-27-09, 04:18 PM
You said you changed the TPS, but still haven't changed the IAC sensor.
changing your gear ratio would have nothing to do with how your motor idles up in down. Only speedo like Scott said earlier....
Im still going to say the IAC like mentioned before
12sws27
10-27-09, 05:05 PM
Yeah Ed. The gear have nothing to do with it. Unless for some reason they were under the hood of the truck and knock a vacuum line lose.
How bout the boost gauge line it's self? Have you checked to see if it might have came off the back of the gauge or something?
I went over it this morning, I did change the PCV valve and re-did the vacuum hose for the brake booster/intake for I wasn't happy with how I did it the first go-round.The hose coupler for the bonnet and tubing wasn't really that tight either.The boost gauge line is still intact.
I know the gears have nothing to do with it, all I'm wondering is if maybe the speed sensor was sending the wrong information to the computer, and it was trying to compensate for it. For don't the speed sensor send information to the computer? or I don't know, maybe I'm way off base here. lol might be trying to make things more complicated than what it is....... Now that I'm an expert at.
But it seems to be running fine now, got a lot more get up and go, geezzzm seems like I can spin the tires for ever now.
If need be, I do have a brand new IAC sensor all I have to do is install it.
Bone Crusher
10-27-09, 06:41 PM
Yes install the IAC if it persists
Gears have nothing to do with your symptoms, so yes your way off
Yes install the IAC if it persists
Gears have nothing to do with your symptoms, so yes your way off
Thought I might be, I was just thinking of the speed sensor,being that everything is computerized.
Took it out for a little spin all I gotta say is dang, with the 3.73's seems like it holds the boost up better on the hiway.
Thought I might be, I was just thinking of the speed sensor,being that everything is computerized.
There are only a few things the engine really cares about to figure out how it runs for the computer:
1. MAF sensor
2. IAC sensor
3. 02 sensors
4. Knock sensor
I believe those are all the major ones, from those the engine can figure out most of what it needs, and those are the ones most likely to cause problems. Items 1-3 are relatively easy to fix, 4 is a ***** to replace (from what I've heard).
The engine doesn't really care about the speed sensor. Speed != how the engine runs. Speed is affected by way to many factors (wind, tires, weight, etc..) for it to be a reliable way for the engine to figure out how well it's running, cause all those factors change how much the engine has to work to maintain a give speed. One day it only needs to run 50% load to maintain a given speed, but the next day it may need to run 90% load to maintain the exact same speed just cause your hauling 1000lbs of stuff in the bed.
There are probably more sensors involved than the one's I listed, but those were just the major ones I know of. Just know speed sensor isn't one of them. :cool:
There are only a few things the engine really cares about to figure out how it runs for the computer:
1. MAF sensor
2. IAC sensor
3. 02 sensors
4. Knock sensor
I believe those are all the major ones, from those the engine can figure out most of what it needs, and those are the ones most likely to cause problems. Items 1-3 are relatively easy to fix, 4 is a ***** to replace (from what I've heard).
The engine doesn't really care about the speed sensor. Speed != how the engine runs. Speed is affected by way to many factors (wind, tires, weight, etc..) for it to be a reliable way for the engine to figure out how well it's running, cause all those factors change how much the engine has to work to maintain a give speed. One day it only needs to run 50% load to maintain a given speed, but the next day it may need to run 90% load to maintain the exact same speed just cause your hauling 1000lbs of stuff in the bed.
There are probably more sensors involved than the one's I listed, but those were just the major ones I know of. Just know speed sensor isn't one of them. :cool:
Okie Doak it wasn't my computer that was mad at me? I really don't know what it was,I replace the PCV valve and fixed the brake boost hose and it seems to run fine,......so far.
Might change out the IAC sensor just for grins and giggles.
LEADFOOT
10-27-09, 11:00 PM
Check the coolant temp sending unit plug. This messed with me for several months.
Not saying this is your problem, just thought I would share this.
For some reason my coolant temp sending unit was missing the little catch part that sticks out to catch the tab on the plug, that holds it in. I guess it may have gotten knocked off when working under the hood or something, and just started getting to where it doesnt make good contact anymore, who knows.
While driving, the truck would just out of nowhere start running really bad and then just go back to normal. The idle would jump up and stay like around 3000rpm with my foot off the gas and stopped, then come back down and misfire like nothing else I've seen. You press the gas and nothing happens, total loss of power, hold it down long enough and it would choke out and die. Turn it off then start it up and it may run like shiz again or it just might run fine for weeks. No DTC's. It started happening more frequently and it was like it would happen when I hit a big bump in the road. The last time it happened I caught it, I saw the coolant temp gauge drop down to nothing. While it was running like shiz I jumped out reached in there all hot as hell and pushed on the plug. Walla...back to normal just like that. You F'n SOB, damn sensors. That explains it happening when a big enough bump was hit.
I bought a new sending unit, installed it, pushed the plug on and the latch tab on the plug broke off. Just my luck. So then I just RTV glued it on. No more problems.
That son of a *****in' sensor. F all these damn sensors. Especially the ones that cause me to pull my hair out.
Just thought I would share that.
Check the coolant temp sending unit plug. This messed with me for several months.
Not saying this is your problem, just thought I would share this.
For some reason my coolant temp sending unit was missing the little catch part that sticks out to catch the tab on the plug, that holds it in. I guess it may have gotten knocked off when working under the hood or something, and just started getting to where it doesnt make good contact anymore, who knows.
While driving, the truck would just out of nowhere start running really bad and then just go back to normal. The idle would jump up and stay like around 3000rpm with my foot off the gas and stopped, then come back down and misfire like nothing else I've seen. You press the gas and nothing happens, total loss of power, hold it down long enough and it would choke out and die. Turn it off then start it up and it may run like shiz again or it just might run fine for weeks. No DTC's. It started happening more frequently and it was like it would happen when I hit a big bump in the road. The last time it happened I caught it, I saw the coolant temp gauge drop down to nothing. While it was running like shiz I jumped out reached in there all hot as hell and pushed on the plug. Walla...back to normal just like that. You F'n SOB, damn sensors. That explains it happening when a big enough bump was hit.
I bought a new sending unit, installed it, pushed the plug on and the latch tab on the plug broke off. Just my luck. So then I just RTV glued it on. No more problems.
That son of a *****in' sensor. F all these damn sensors. Especially the ones that cause me to pull my hair out.
Just thought I would share that.
LOL LOL It's really good to know I'm not the only who has weird and strange problems, a lot of mine are self inflected though, lol
I'll check on that,too, might want to check the oil pressure sending unit as well.
These dang computerized mechanisms, I thought bills,worrying, and kids gave you gray hair, but I've noticed mine really getting gray here lately.
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