Still smoke issue

[BeastMaster]

I’ve also noticed something that just started happening recently, when I’m accelerating at a steady pace, at around 1700 rpm’s it’ll occasionally spike 2-300 rpm’s for like 2 seconds, then drop back down, all while I’m still accelerating. What could cause this ?

I am presently chasing something similar...and it seems to have something to do with my transmission controller. It comes and goes. Right now, it's showing up again. I am pretty confident I have a bad connection somewhere in the TPS circuit, and I am tracing through with an oscilloscope to trace where all the "noise", that comes and goes, is coming from. It's not the TPS sensor itself...but it seems to be somewhere nearby. It's not PCM power. That's clean. The old TPS had a noisy spot in it where the resistive element had wore through. It was unmistakeable when seen on the oscilloscope. Just turning the engine on ( but not starting it ) and operating the accelerator pedal and that spot stood out like a sore thumb.

Right now, I am investigating some connectors which may be compromised.

As for your smoke, when I first got my van ten years ago, the PO had let it sit for years and was using it as a storage shed. It smoked, I retained the services of a professional diesel mechanic to guide me in the selection of my beast, and his advice to me to clear up the smoking ( it wasn't bad, but I had just as soon not be seen with it smoking in Southern California! ) by using "Diesel Extreme Hot Shots" and Stanadyne additives in the fuel. Whether it was this, or me placing the vehicle back in service as a daily driver, "fixed" the issue, I no longer smoke nearly as much as it did when I first got it. I believe there was a forum here that also discussed HotShots additive for lubrication and cleaning of IP's and injectors. That's just my two-cents worth.

In the ten years I have owned this beast, it's been a mixed blessing. Mechanically, its been great, however I have had a lot of disappointment with electrical things that should last forever, but don't. The underlying physics are sound, but the manufacturing quality of the replacement parts sometime leaves a lot to be desired. Things like starter motors, relays, tach sensors, and the way the FIPL sensor is implemented.

 

[Coltonreece]

After reading this again in your quote, I wonder if the torque convertor is locking and unlocking. That's about the RPM change that happens during lock up or unlock. Although I think it should only happen in drive and overdrive. I don't think there's any lock up in first and second.

Since you mentioned no lock up in first or second, i have noticed it only happens when I’m getting on the highway and trying to gain highway speed, not in lower gears driving around town. How would i go about checking the torque converter?

 

[Coltonreece]

I am presently chasing something similar...and it seems to have something to do with my transmission controller. It comes and goes. Right now, it's showing up again. I am pretty confident I have a bad connection somewhere in the TPS circuit, and I am tracing through with an oscilloscope to trace where all the "noise", that comes and goes, is coming from. It's not the TPS sensor itself...but it seems to be somewhere nearby. It's not PCM power. That's clean. The old TPS had a noisy spot in it where the resistive element had wore through. It was unmistakeable when seen on the oscilloscope. Just turning the engine on ( but not starting it ) and operating the accelerator pedal and that spot stood out like a sore thumb.

Right now, I am investigating some connectors which may be compromised.

As for your smoke, when I first got my van ten years ago, the PO had let it sit for years and was using it as a storage shed. It smoked, I retained the services of a professional diesel mechanic to guide me in the selection of my beast, and his advice to me to clear up the smoking ( it wasn't bad, but I had just as soon not be seen with it smoking in Southern California! ) by using "Diesel Extreme Hot Shots" and Stanadyne additives in the fuel. Whether it was this, or me placing the vehicle back in service as a daily driver, "fixed" the issue, I no longer smoke nearly as much as it did when I first got it. I believe there was a forum here that also discussed HotShots additive for lubrication and cleaning of IP's and injectors. That's just my two-cents worth.

In the ten years I have owned this beast, it's been a mixed blessing. Mechanically, its been great, however I have had a lot of disappointment with electrical things that should last forever, but don't. The underlying physics are sound, but the manufacturing quality of the replacement parts sometime leaves a lot to be desired. Things like starter motors, relays, tach sensors, and the way the FIPL sensor is implemented.

Thanks for your input I appreciate you !!

 

[IDIBRONCO]

How would i go about checking the torque converter?

That one's beyond me. I don't know much about transmissions.

 

[asmith]

Since you mentioned no lock up in first or second, i have noticed it only happens when I’m getting on the highway and trying to gain highway speed, not in lower gears driving around town. How would i go about checking the torque converter?

Someone on here has wired up led lights on the dash to let him know when the converter was locking up and unlocking, and they did something else to, but I cant remember what at the moment. How he did it I am not sure. You would need a good wiring diagram for the transmission harness.

 

[BeastMaster]

Since you mentioned no lock up in first or second, i have noticed it only happens when I’m getting on the highway and trying to gain highway speed, not in lower gears driving around town. How would i go about checking the torque converter?

I get the idea you just did.

I believe the torque converter is the first thing the engine shaft is connected to which feeds the transmission, and it's purpose is to allow the vehicle to come to a dead stop while the engine is running...a fluidic clutch, so to speak.

Had the torque converter failed...you would not have gotten the vehicle moving again by engine power. The fact you noted first and second seem normal, I believe you just cleared your TC from the suspect list. I am leaning toward the solenoid controlling the TC lockup being erratically controlled due to the Transmission Control Module receiving bad info from the sensors.

Three sensors and the coast clutch override button on the gear select lever are considered by the TCM to select a gear and whether or not to engage the torque converter lockup or lock the coast sprag.
* FIPL ( TPS ) accelerator pedal position
* Tach Sensor ( a frequency ) from the speedometer PSOM or the transmission.
* Vehicle Speed Sensor ( another frequency ) from the rear differential pumpkin.

Any of these sensors.sending flakey data will cause the controller to make flakey decisions. Failing/noisy PCM power is also known for inducing chaotic gear selections. Sensors sending flakey data usually throw a code. It's been my experience that a slightly off TPS gets accepted and acted on, without throwing a code, but it ain't right. I am presently chasing one on my van. Irritating little fella. I mess with anything and he goes away...for a while...then shows up again. Like trying to find a damn rattle.

Can someone chime in if I am in error? I am not all that savvy on the finer details on transmission operation.

 

[Coltonreece]

Check out my most recent post thanks for ur input !