Ok, its that time of year again when the temperature dips below 40*. The EBPV kicks in again. The problem I am having is the same as last year. I replaced the EBPV sensor and the cleaned the tube and checked for leaks. Everything is was fine on the tube. But the problem I have sometimes at idle it opens and closes and a very fast pace open close in less than 2 seconds, over and over and over again. Other times it just closes off and sounds like a jet engine like it is supposed too. I also noticed the open and close very fast when driving down the road between 1500rpm-2200rpm. Below 1500rpm I just get the jet engine sound, and above 2200rpm it opens up completely as it should. I assume this is not normal for it to act this way. Also when it opens and closes fast the the Rpms very about 500-1000rpm and the vehicle seems to surge back and forth as it closes and opens. So if I replaced the EBPV sensor what next. Thanks.

 

Have you checked to make sure the valve itself can operate smoothly? Binding possibly?

Or... (and this is TOTAL speculation here!):

What if for some reason, the computer tells it "open to 20%" but for some reason it physically opens to 60%. Then the computer reads that, and pulls it back in. At which point, it again tries to open to 20%, and again, something physically has it opening more that the prescribed amount. This continues until your engine is warm enough and the computer says "open 100%" which it has no problem doing.

Basically I'm wondering if there is somehow a "groove" worn somewhere so that during a certain part of the stroke of the valve it opens more than it should, and the computer battles to control the stroke.

Again, total speculation and would be a ROYAL pain to confirm (remove & disassemble turbo... fun) but just thought I'd throw that out there. Maybe someone smart will come along and have a good idea. Best of luck!

 

My old '99 PSD used to do the same thing. The idle would fluctuate on mornings around 40 degrees or so just like you described. I cleaned my tube and sensor and it did nothing. I would often times step on the throttle and it would go away but come back if I didn't drive off yet. So how did I fix it, you ask? I traded that truck in on my crew cab...

 

Your old truck wasn't a white extended cab like pictured in his avatar was it?

Try unplugging the IAT sensor (the little gray one you zip tied somewhere when you put the 6637 in) to see if that makes the problem go away. That should disable the EBP circuit and make sure you are dealing with an EBPV problem.

 

Ha! No. It was dark red...

I still see it running around town but the current owner got side-swiped and never fixed the dent...

Back on topic, so that little sensor feeds ambient temp readings to the PCM? Never knew that.

 

What should it do if I unplug the IAT sensor?

 

It's supposed to make the computer assume it's warm enough outside that you don't need the EBPV to close. You could unplug the EPB sensor or the solenoid on the EBPV instead to accomplish the same thing, but I figured this one was easier to reach. Basically you just want to disable the EBPV to make sure you don't have the same symptoms so you know for a fact that's what your problem is.

If you've got some time on your hands you could skip this step and start inspecting the linkage to make sure everything is moving like it's supposed to, but that stuff is a little hard to reach. It won't hurt to run your truck with the EBPV disabled. Many here have deleted this function. If unplugging your sensor fixes your issue, you'll at least have the time to address this on your own schedule.

 

Ok, I unplugged it and it did exactly as you said, the EBPV turned off, I would like to fix this problem, but I am not going to have anytime for a few weeks since it's fall. Is it ok to run it with temp sensor disconnected? I am always really easy on my truck when it is cold outside. Will it through any codes, if the sensor is not plugged in, or will I get SES light? What are the steps to fixing the problem when I have time in a few weeks? What to check first and so on? Thanks

 

Yes it will throw a soft code saying the sensor isn't working (cuz you unplugged it) It won't trip the check engine light.

It won't hurt one bit to run this for weeks on end with this disconnected. Some people have deleted the EBPV all together. So take your time and get around to checking it out at your convenience.

 

I guess the next question is what to check, when I get time, I haven't spent a lot of time around the turbo so I don't know where to start, or what it should look like when its normal.

 

As suggested earlier, you could check for smooth operation of the EBPV actuator rod. The problem will either be a physical issue, as with the rod, or a sensor issue, which would require a scanner or spare parts to diagnose.