surging/pulsating

Brianawd · **Joined:** Wed Apr 03, 2013 12:59 pm **Posts:** 130

Ok so I have this issue of surging/pulsating. Driving around in the jeep I get this surging almost like a miss in a gas car. The issue is more pronounced under load like climbing a small hill around 55mph,(not shutter as I have euro converter)
whast odd is if I drive it for 30min and then park it for 10-15 mins the issue is gone and the jeep runs perfectly smooth. I know when the issue is gone because when the jeep is in drive it will idle perfect. When the issue is there in runs a little rough. It does this every morning and every after noon on my way home. Like I said above issue seem to go away after sitting for a little bit.

So far I have check for air in fuel-none,have lift pump installed
Charge pipes both good and new
alternator charging 14.3volts with everything on. 14.6 with everything off
trans filters new oem,fluid all new and perfect
watched rail pressure to see if I can see a big drop or rise in pressure- No big changes found.
No codes showing up

I'm thinking maybe egr and fcv but I have the GDE hot tune. So egr should not be a issue.

I love the little jeep but I'm almost at my wits end with this thing. I work on 12.7L-16.0L diesels all day and have never had a issue like i have in my crd. If I can't figure this out it may be time for the jeep to go by by and pick up a new 2014 tacoma.

geordi · **Posted:** Fri Dec 27, 2013 12:58 pm

Believe it or not, but it could be the alternator pulley. Is the serpentine belt bouncing at all?

Another possibility is the MAF is sending garbage information. Try unplugging it, and drive like that for a bit. See if anything changes.

Brianawd · **Joined:** Wed Apr 03, 2013 12:59 pm **Posts:** 130

geordi wrote:

Believe it or not, but it could be the alternator pulley. Is the serpentine belt bouncing at all?

Another possibility is the MAF is sending garbage information. Try unplugging it, and drive like that for a bit. See if anything changes.

Alternator pulley is new as of 8 months ago. Belt is not bouning at all. Nice and smooth.

I will try unplugging the maf today when I head home. But I thought the maf was, for the most part not even used when you had a GDE tune. also if I unplug the maf will it show a CEL light even with the GDE tune?

Hexus · **Posted:** Fri Dec 27, 2013 3:12 pm

KD6ICZ · **Posted:** Fri Dec 27, 2013 3:26 pm

I think most of us have experienced the surging at one point or another. Mine does it for awhile then takes a break. Going down the highway I occasionally feel a pulse here and there. When starting cold it's real bad until the engine warms up. I always thought it had to do with how much buildup was in the intake. Even though you have the GDE tune now there might still be buildup from before the tune. Mine stopped for awhile after I changed the MAP sensor. But it's doing it again.

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kjjet · **Posted:** Fri Dec 27, 2013 3:43 pm

Brianawd,

I use to have surging a lot until I removed the EGR & FCV completely. You just never know when those systems may act up and there is no way to know without completely removing.

It also may be bad or failing Rockers. I did both together, then no more issues.

Good luck.
KJJET

Brianawd · **Joined:** Wed Apr 03, 2013 12:59 pm **Posts:** 130

kjjet wrote:

Brianawd,

I use to have surging a lot until I removed the EGR & FCV completely. You just never know when those systems may act up and there is no way to know without completely removing.

It also may be bad or failing Rockers. I did both together, then no more issues.

Good luck.
KJJET

EGR/FCV is on the top of my list. I'm not thinking its a rocker issue because of how its intermittent. But I could be wrong.

I'm going to unplug the maf today to my drive home from work. If that does not fix the issue then this weekend I will get to work with checking all the egr doo doo.

Thanks every one for all the info.

geordi · **Posted:** Fri Dec 27, 2013 9:01 pm

With regard to the FCV, just plan to leave the unit itself in place and simply unscrew the disc from the center shaft. Yes, the unit has to be removed to do this, but that is easy enough. Once the disc is gone from the airflow, that part of the system is quite effectively neutered.

Brianawd · **Joined:** Wed Apr 03, 2013 12:59 pm **Posts:** 130

Well unplugging the maf did nothing. Same issue. So I plugged it back in. I then unplugged
The FCV. That made the jeep run even worse. Missing at all time and acting
Like it was on 3 cylinder at idle. So I plugged it back in.
Next round I'm going to block the egr and see if that helps

geordi · **Posted:** Fri Dec 27, 2013 10:57 pm

I wonder if maybe your FCV is stuck partly closed? The thing has plastic gears, and if they have stripped in the wrong spot, the disc might be holding the intake partly blocked. Your EGR may also be leaking, which will allow boost out (causing smoke) and excess filth back in (when at low boost)... Neither of which is a desired operation.

You certainly don't need that FCV disc there, it is only part of the EGR system. If you are going to fully block the EGR (which I whole heartedly support) then absolutely pull that disc and forget the CRD ever had it. If it still is running funny, then the MAP sensor might be at fault.

Brianawd · **Joined:** Wed Apr 03, 2013 12:59 pm **Posts:** 130

I checked the FCV and it was all the way open. I had my wife turn
The jeep on and off when I was looking at it. It did nothing. It stayed open the whole time. What gets me is why the jeep ran like doo doo with it unplugged. I already pulled the
FCV and will be blocking the egr Sunday. It was on my list to do anyway.

kjjet · **Posted:** Sat Dec 28, 2013 2:22 pm

I pulled the hole FCV and spilt the unit, and reinstalled the flange to the intake elbow using shorter bolts and heat resistant sealant.

Doing so cleans things up and makes it easer to get to the EGR/ Cooler package. Remove the hole package.

FYI... It still could be the Rockers. As they start to fail, you will build up soot due to the valves not opening all the way. As the soot builds and dislodges the engine will loose and gain power. I'm not saying that's it, but don't rule it out.

Good luck.
KJJET

CATCRD · **Posted:** Sun Dec 29, 2013 4:18 pm

Brian, you sound like a diesel tech, so I hesitate to suggest it, but I haven't seen the fuel filter mentioned yet. I would just change it to see if it affects anything. I know that will cause more problems at load than idling, so it kinda fits.

Unplugging the FCV probably causes the EGR valve to duty cycle much more than normal, in an attempt to meet the EGR setpoint. That may be why it runs like crap with only that unplugged.

No change in behavior with the MAF unplugged suggests your original surging problem is not related to EGR.

Brianawd · **Joined:** Wed Apr 03, 2013 12:59 pm **Posts:** 130

CATCRD wrote:

Brian, you sound like a diesel tech, so I hesitate to suggest it, but I haven't seen the fuel filter mentioned yet. I would just change it to see if it affects anything. I know that will cause more problems at load than idling, so it kinda fits.

Unplugging the FCV probably causes the EGR valve to duty cycle much more than normal, in an attempt to meet the EGR setpoint. That may be why it runs like crap with only that unplugged.

No change in behavior with the MAF unplugged suggests your original surging problem is not related to EGR.

Fuel fuel filter was changed about 10k miles ago. At the same time I did the GDE hot tune cleaned the map, Built a catch can. I do have a new fuel filter sitting on the shelf in the garage. So if blocking the EGR does not help I will try changing the filter.

What I'm thinking is going on is the egr is sticking open when its cold. Once it warms up, its then able to cycle closed.

What annoys me is no codes. So i'm chasing my booty. I have never worked on a diesel that has so many little issue. Make me wish I would have just built a jeep wrangler with a 4bt

CATCRD · **Posted:** Sun Dec 29, 2013 11:15 pm

It's a lot less work to change the filter than block the EGR and10,000 miles could easily block your filter.

Brianawd · **Joined:** Wed Apr 03, 2013 12:59 pm **Posts:** 130

Well egr is block and same doo doo different day. I will change the fuel filter tomorrow but I don't think that is going to fix the issue. I'm starting to think
it may be a injector having issue. I know people saying Lifters rockers. But I don't think that's the issue because the issue comes and goes and the leads me to think electrical. If it was the Lifter and rockers it would do it all the time and not come and go.

At this point I'm just going to drive it the way it is. If it blows up oh well. I'm not putting any more time or money into this pile of doo doo. I was hoping to drive it for the next 6months. At at that point the wife is done with school and then leaves for OCS. If it makes it tell then great. If not I will end up getting a new Tacoma early.

SargeIndustries · **Posted:** Mon Dec 30, 2013 5:05 pm

I would make sure the copper washers around the injectors are not leaking. Mine had intermittent pulsing and it was the copper washers every time. They may leak most when it is cold and then lesser when hot and everything is expanded. You will know which one is leaking because the injector will be glued in its hole with carbon buildup. Be prepared to borrow a puller....

Brianawd · **Joined:** Wed Apr 03, 2013 12:59 pm **Posts:** 130

SargeIndustries wrote:

I would make sure the copper washers around the injectors are not leaking. Mine had intermittent pulsing and it was the copper washers every time. They may leak most when it is cold and then lesser when hot and everything is expanded. You will know which one is leaking because the injector will be glued in its hole with carbon buildup. Be prepared to borrow a puller....

Injector coppers were replaced about 2k miles ago. My pulsing comes and goes even when hot. It will run like doo doo when first started in the morning all the way to work. Then on the way home it will do the same thing but some days it will clear up and run fine. when it clears up its after I have been driving it for about 20-30min and then turn it off for some time. Like if I meet my wife for dinner some place. After dinner when I start it back up to head home it runs perfect.

This is everything I have done to this POS since march 2013
Lift pump
GDE hot tune
new map sensor
new fuel filter
new injector orings and coppers
new injector fill spill kit
New euro converter
new rebuilt trans
rebuilt front drive shaft
FCV delete
egr delete
DYI provent
cat delete

No codes when its having its issues.

kjjet · **Posted:** Mon Dec 30, 2013 7:37 pm

Dam... I feel your pain! Hopefully you were warned, these Jeeps + CRD = Problems!

Are you loosing any Anti-Freeze or pushing coolant to the right side overflow of the tank? Could be a head gasket? If it runs bad when first started you may have a loss of compression, as it warms up it gets better?? Just a guess.

Good luck
KJJET

Brianawd · **Joined:** Wed Apr 03, 2013 12:59 pm **Posts:** 130

kjjet wrote:

Dam... I feel your pain! Hopefully you were warned, these Jeeps + CRD = Problems!

Are you loosing any Anti-Freeze or pushing coolant to the right side overflow of the tank? Could be a head gasket? If it runs bad when first started you may have a loss of compression, as it warms up it gets better?? Just a guess.

Good luck
KJJET

Knock on wood but my pos has not lost a drop of anti-freeze at all and it only uses up about 1/2-1qrt of oil every 6k miles.

surging/pulsating

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