First thing happened RPM's dropped from about 950 to 800, but were steady.

Took it to mechanics couldn't undo the crank pulley nut, took it to dealer. They took belt out , rang me and said I have to pay 150% on top of quoted price as the water pump is located behind. Forwarded them coloradowheel thread and they did it as quoted.

Changed Belts, Water pump, pulleys, tensioner, flushed coolant.



Started getting more black smoke 1st, 2nd, 3rd accelerating. No smoke on motorway. Nothing out ordinary during high acceleration at speed.

Doesn't start from first pop as used to.

RPM's started jumping between 720-870 when heats up, cold steady.

Higher MPG's.

No codes.

Cleaned MAF, MAP, new air filter.

Checked with a scanner, fuel rail pressure jumps between 5720 -6370 psi.

Contacted one guy he said it's the High Pressure Injector Pump Regulator Valve.

Now, how do I check it and how do I get to it without a ramp? Any other precautions, do I need to block fuel line? Any pics?

Much appreciated.

From what u said you had the normal timing belt service done. How many miles are on the jeep and what year is it? Black smoke is most often excess fuel in proportion to air available for combustion resulting from not developing enough boost and the most common cause of this is a loose or cracked boost hose. Do you have the original boost hoses or have they been replaced with the Silicone type like Samcos? Check closely for loose clamps or a crack in the boost hoses they often have excessive oily residue sometimes you can hear a hissing sound from a larger crack.
Does the jeep have a Check engine light on and if it does were the codes read and what were they.

It shouldn't require ramps to change the fuel regulator sensor but I wonder why someone thinks its the problem since it sounds like relatively excess fuel not a lack of fuel and once there is adequate pressure the ECM and injectors control the amount of fuel delivery to combustion chamber. If those pressures are psi they appear to be low. There are several here that are much more familiar with the fuel system than I am and I am sure they will chime in to help further.

Start with inspecting the boost hoses classic symptom black smoke on acceleration.

_________________
05 Blu LIM, OME GDE Tbo, wk II 245/75/17, KC Lights, bull bar, 195K H TC
05 Blu Lim, Dayton, GDE HT, 255/75/18 , 210K , H TC
06 Bla Lim, GDE Eco, Destination AT 245/75/17, 151K, H TC
06 D Khaki Lim 126K wkII Eur TC
05 D khaki Lim 145k refurbishing
All CRDS: Fumoto, Lift , Fan Shroud mod, fuel head Gen II, SAMCOS,self TB, 2 Mic filt, Hayden

It's KJ 2007 2.8 crd , hoses seem fine, 140.000, original hoses, no check engine light, capped EGR at around 60.000.

I am assuming he thinks it's because of the jumping pressure.

Just don't know how to get to it to inspect, tried youtube, but no videos.

Thanks in advance.

Are you in the North American market, or are you offshore?

It's a european model.

I'm not in US.

If you suspect a fuel problem, first thing to do is replace the fuel filter.

Black smoke is typically from not enough air getting into the engine.
If your scan tool can read fuel rail pressure it can probably also read manifold pressure.
So, watch the manifold pressure reading while driving and report what you see.
Also inspect all the intake and turbo hoses.

Honestly, given all the symptoms, I suspect badly worn or damaged rocker arms.
But a lot of other things can be checked before tearing into the engine.
I don't think its anything related to the fuel injection pump or fuel control solenoids.
Fuel rail pressure will naturally go up and down according to RPM.
If RPM is changing, so will fuel pressure.

_________________
U.S. Army Retired

Done fuel filter recently and have been doing it every 10 for the last 5 years, same with oil, air filter changed more frequently. Do you think rocker arms could be an issue at 140,000 km ? I'm not a diesel mechanic, but I think those should last longer, no?

Inspected hoses, seemed fine, tiny bit of oil, but after 140,000 it's ok, I'm guessing.

MAP idling 14.6 psi and then changes to 13.2 psi as warms up a bit.

MAF 0.04 LB/s while idling.

Will try recording figures while driving.

Have added a bottle of Injector Cleaner, see how it'll go.

Does your CRD have a fuel lift pump in the tank?

I believe so, I think it's standard for these models.

No you don't have intank fuel pump TDF is correct if you need to look into a possibility of air in the fuel system. also you need to go back and double check your timing injectors etc,, and at the end it may be worn out rockers (someone else suggested earlier).

I wish I could confidently say no.

I don't know in what order symptoms started occurring but its possible that a botched timing belt job could have damaged the rocker arms.
Or maybe its just abnormal wear and tear.
Both are possibilities.

Again, keep checking for other things.
Maybe its a bad injector?
But this does not seem like a fuel system problem.

_________________
U.S. Army Retired

Thanks,

How could rocker arms get damaged during the belt change procedure? It was a dealer, I believe they had all required tools to lock the mechanism.

I've added an Injector Cleaner and seems that it helps, engine is more responsive as well as a bit more noisy, less smoke, MPG's are going down.

Will listen for ticking sounds ( worn rocker arms ).

Regards.

The rockers will usually get bad when the roller stop turning...…..

Is this engine single overhead cam ?

It is DOHC,

Actually injector cleaner only dropped MPG's and helping fuel to burn, because of that engine produces a bit less smoke.

RPM's still jump while idling.

Tried to hold accelerator pedal steady on 1000, 1500 and 2000 rpm's, engine is steady but the Fuel Rail Pressure rises with acceleration and jumps in a range of 300 psi.

Regards.

Just out of curiosity: can you drain the water out of the fuel filter and see if there's any change after that?

_________________
2005 KJ CRD Limited 4x4:
245/75R16 BFG TA KO2s
OME / Clevis 2.5" Lift
JBA Lifted A-Arms
IRO WJ Short Rear UCA/WWDiesel mount
Skid Row Skidplates
HDS Model 001 Thermostat (190°F)
Suncoast TC
Full Weeks Kit
Bosch 5V glow plugs
Hayden 2986 fan clutch / GM 11-blade fan
Samco / Sasquatch Intake Hoses
Carter in-tank pump
Provent 200
V6 Airbox

Thanks for the clue.

The filter is newish and I never had to do that before, I'll try and see.

The funny thing is it doesn't do it every time.

When you drive for a bit and stop ( idle ) rpm's steady, after 30 - 60 sec start jumping. It smokes more than usual only after RPM's jump. RPM's only noticeable jumping while idling, otherwise you don't feel it.

If you drive and stop ( stop for very short time before RPM's start jumping ) it doesn't smoke as much. Something builds up.

Another thing comes on and off is when you drive at around 1500 RPM steady it kind of jerking sometimes, not much, but i can fill it. As if it's starving on fuel or not getting enough air.

I would test injectors, and by the way im the only one on this forum to experience injector #! sticking so bad that it almost burned a hole through the piston so I suggest testing them, the rest of the guys here didn't get too much luck with injectors sticking. but I did have that experience.

How should I test them?

Pull out and inspect?

Cheers.

I think I'm going to clean all injectors first and see what they look like.

https://www.youtube.com/watch?v=XK7U9gotGhE

don't take them apart, just send them to Bosch fuel injection shop. they will test it for you.