Long crank to start

Oilcan · **Joined:** Tue Jan 07, 2014 4:39 pm **Posts:** 9

My 2005 KJ CRD is now turning over for 6 to 8 seconds before it catches and starts. Ive replaced the fuel filter head and filter as I first thought it was a fuel problem but this hasnt made it any better. Im now thinking about the crank shaft position sensor. Any thoughts on this please as i dont want to be buying parts that i dont need. I should also add that im in the UK if this makes any diffrence

rankom · **Posted:** Wed Feb 24, 2016 6:38 pm

first make sure glow plugs are working , 2nd check for air in fuel , ? does it drive ok ? losing power or running rough ?

Oilcan · **Joined:** Tue Jan 07, 2014 4:39 pm **Posts:** 9

The glow plugs were changed around 6 months ago. Im certain that all the air is bleed from the fuel. It runs fine once started. It makes no diffrence if the engine is upto temp or cold. Once in every 30 to 40 times starting it will start as it should

flash7210 · **Posted:** Thu Feb 25, 2016 8:44 am

Need more details.

What year is your CRD?
Any smoke out the exhaust while its cranking?
Any smoke after it has started?

I too would suspect a problem with glow plugs or fuel supply.
If it were a bad crank sensor, the engine would not start at all.

Billwill · **Posted:** Thu Feb 25, 2016 10:52 am

Are you 100% sure that the battery is good...been tested under load?
Put a voltmeter across it while cranking...should not drop below about 10 volts.

Make sure the battery connections are clean and tight, the negative lead going to chassis is clean and tight and the grounding strap earthing the engine to chassis is clean and tight both ends.

Check the connections on the starter/solenoid are clean and tight.

Any codes posted?

Oilcan · **Joined:** Tue Jan 07, 2014 4:39 pm **Posts:** 9

Model year is in OP its a 2005 no smoke whilst cranking and a little normal type once started then it goes away. New battery last year so its good. No idea about the engine to chassis earth strap. Where abouts is that connected ? Starter connections are clean and tight p0039 comes up on dash display so dont know how that affects the starting as that seems to be to do with turbo. Im not sure if this is a historic fault or new as i dont have the equipment to clear the codes

flash7210 · **Posted:** Thu Feb 25, 2016 12:15 pm

You sure its a p0039?
Sometimes the dash display mixes up the last two digits in which case it might actually be a p0093.

P0093 = Fuel System Leak Detected - Large Leak

Oilcan · **Joined:** Tue Jan 07, 2014 4:39 pm **Posts:** 9

As I have no other method of getting a p code and theres no fuel leak let alone a large leak then I can only assume its correct

rankom · **Posted:** Thu Feb 25, 2016 8:44 pm

i agree with guys suggestion, always start with battery test , and low pressure fuel system double check , some times dropping fuel tank to see fuel sending unit and filter, and then high pressure side , fuel rail pressure , injector return test etc rail to injector cap test etc . but most important is start with basics. its just could be fuel drain back problem ?

Oilcan · **Joined:** Tue Jan 07, 2014 4:39 pm **Posts:** 9

Ive put a non return valve inline so it shouldnt drain back. I guess ill be taking it to a garage to be looked at

rankom · **Posted:** Sat Feb 27, 2016 10:48 am

yes diesel shops have testing equipment, and they will monitor fuel pressure and check it properly , it could be just a simple problem like sticking MPROP valve or small leak in fuel system , good luck

Oilcan · **Joined:** Tue Jan 07, 2014 4:39 pm **Posts:** 9

Just a little update. It finally wouldnt start at all so new crank shft position sensor was fitted. It still needs to sit with the key in position 2 for around 20 seconds before it will start as it should

rankom · **Posted:** Sat May 28, 2016 5:48 pm

how old is the battery is it 800cca ?

Rixram · **Posted:** Thu Jun 02, 2016 11:27 am

flash7210 wrote:

If it were a bad crank sensor, the engine would not start at all.

Actually, mine was hit & miss for a month. One day, it'd start fine. The next day (or later in same day), it'd crank and never fire, or finally fire after obscene amounts of cranking. I had a bugger of a time diagnosing a failed CPS because of that.

Usually, you expect electronics to either work or not. My crank posit sensor failure was intermittent.

Since this is becoming a more frequent complaint of failure among KJ CRD owners, it might be an ideal time to just spend the $80 and replace it. It just may (I speculate "will") fix your issue.

EDIT: I finally caught the part where you already said you'd replaced the CPS.

Oilcan · **Joined:** Tue Jan 07, 2014 4:39 pm **Posts:** 9

Just to update once again on this. Weve been waiting the 20 to 30 seconds before starting and its all been fine until a cold spell recently when weve had to crank 2 or 3 times befire it would start. We have now got our mechanic to fit new glow plugs but still have to wait before cranking. When we went to collect the vehicle he mentioned that he disconnected a " pressure relief valve at the back of the pump" and it started straight away. He also mentioned that the engine shouldnt start with this disconnected and saya that this may be the cause of the starting issue. Has anyone heard of this or can maybe shed some light as to what part he is talking about. Many thanks in advance

WWDiesel · **Posted:** Mon Nov 14, 2016 5:25 pm

It is a fuel quantity valve mounted on the back of the CP3 fuel injection pump. It is replaceable...

see this trouble shooting guide on the MPROP from Oregon Fuel Injection:> http://oregonfuelinjection.com/pdf/jeep ... nostic.pdf
It gives a good description of problems... :wink:

The function of the part is to control the output pressure of the high pressure CP3 fuel pump. It controls the amount of diesel fuel that is returned back to the fuel tank and therefore controls the high pressure fuel pressure being sent to the fuel rail.

From an earlier post on LOST by gmctd he explains its function in detail: > viewtopic.php%3Ft%3D25047

FUEL QUANTITY SOLENOID

DESCRIPTION
The Fuel Quantity Solenoid valve is located on the back of the front cover of the high-pressure pump. The solenoid is pulse-width modulated by the ECM and meters the amount of fuel that flows into the high-pressure elements inside the high-pressure pump.
The solenoid is inactive up to 30 seconds after IGNition switch is initially keyed to ON position to allow maximum fuel pressure to the fuel rail during cranking and start up. ECM assumes FQS valve control when CPS signal and rail pressure are within acceptable limits

OPERATION
The Fuel Quantity Solenoid valve is a pulse-width modulated valve that controls the amount of fuel sent or delayed to the high-pressure pump elements inside the high-pressure pump. The ECM determines the fuel pressure set point based on engine sensor and rail-pressure inputs. If the actual fuel-rail pressure is too low, the ECM commands the solenoid to allow more fuel to flow to the high-pressure pump. This minimizes the difference between the actual fuel-rail pressure reading and the set point. The ECM will also operate the solenoid to delay fuel, reducing flow-rate, if the fuel-rail pressure becomes too high.
The FQS valve is commanded open by the ECM to allow the high-pressure pump to build maximum pressure (1600bar, 23,206psia), or closed to decrease pressure.
Thus, rail fuel-pressure can be increased or decreased independent of engine speed

The valve also has a fuel tank heat-protection function* that meters the exact amount of low-pressure fuel to the high-pressure pump to prevent excessive injector-heated fuel from returning to the fuel tank.
Temperature of fuel from the fuel tank is measured at the fuel inlet in fuel manager head via a temperature probe in the inlet side of the fuel-heater module.

Oilcan · **Joined:** Tue Jan 07, 2014 4:39 pm **Posts:** 9

Thanks for that. Ill have a read through. Would you think this is a possible cause of my problem starting?

WWDiesel · **Posted:** Mon Nov 14, 2016 8:56 pm

Oilcan wrote:

Thanks for that. Ill have a read through. Would you think this is a possible cause of my problem starting?

Absolutely a good possibility!

Long crank to start

Who is online