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1.8 TDci dies when returning to idle, lumpy idle.

5.9K views 4 replies 2 participants last post by  BPetean.PBA  
#1 ·
Hello,
I've searched the google a couple of days and everything that I found did nothing to my issue.
Ford Transit Connect 1.8tdci Europe 2008.
The car is starting and runing great, great performance and consumption, low level of smoke.
The problem is that if I start the car and let idling, after aprox. 30 sec it starts misfiring (lumpy idle, does not die) and if I hit the gas over 1500 rpm and let idle again it dies directly. It happens while cruising also, as soon as I hit the clutch and the engine is going to idle, it dies. When does this the rail pressure goes almost to 0. Errors present P0087 P0088 which is rail pressure too low and too big.

Changed until now.
Refurbished head due to 2 cracked valves on cil no 3.
New timing belt.
Injectors checked on test bench, all god.
Replaced the metering and the pressure regulator valve from the pump also the sensor from the rail (spider). no change.
Checked wiring.
New EGR
New MAF
Fuel filter changed twice now.

The DMF is playing around:)) planning to do that later after I will solve this issue. Can a worn out DMF doing my issue? I've seen engines with completely destroyed DMF which were running like crap...

What I am planning to do next.
Replace camshaft and crankshaft position sensor
Check the leak off from the injectors on the engine, i think one or more injectors are remaining stuck opened and the rail empties, the pump cannot hit the requested pressure and the ECU is shutting down the engine.

What I know but I need someone to approve or correct me.
When the two errors P0087 and P0088 are together it means that something cannot keep up with the rpm changes and the rail pressure is suffering. The metering valve or the pressure regulator valve (PRV)?
I know that the metering valve is only supplying the HPFP and the PRV is supplying the rail. I replaced both valves and didn't cured my issue, could it be the HPFP which cannot keep up?
The leak off pipes from the engine has some sensors/valves or something on them, what is the purpose of them?
What happens when the engine is going to idle from higher RPM? What closes and opens to keep the engine idling? Something is lazy on doing that!

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#2 ·
If the crank sensor is on the flywheel then a failing DMF will not help diagnosing issues. A bad signal
may send the car into a shutdown mode briefly but then it gets a clean signal and a high/low pressure
fault may get recorded.

What fuel pressure are you getting at idle, 2000, 3000 and 4000 rpm. (whilst parked, not moving)

A leakoff test is a quick and cheap test, how much are they leaking off? Let us know which
procedure you used to test. Idle for how long and revs @rpm for how long etc...

Decent brand of fuel filter? Any air bubbles in the low pressure side to the pump?
 
#3 ·
I knew the part with DMF that can affect the signal from the CKP(thanks for that) and if I recall sometimes when i let the engine to go to idle, he goes to something like 500 and then rapidly up to 900 or so and steady after that and sometimes dies directly.
Next days i will try to record the pressure on the entire rpm range and make the leak off test. I have to buy the tools first. Planning to do 1 min at idle and 1 min at 2000 rpm and compare the quantities.
Bosch and MANN fuel filters, premium i should say. Didn't checked the return for bubles, the pipes are black. Will put a transparent pipe and see if there are bubbles or not.
 
#4 ·
Its not the return you check for bubbles its the feed to the high pressure pump or either side of the filter.

Don't forget that the return lines need to be capped when testing the leakoff, otherwise air can enter.
 
#5 ·
Came back with the solution.
You will not believe what the issue was 😂
Some mechanics some time ago
replaced the plug from the fpr and they mixed up the two plugs from fpr and metering valve from the hpfp.
Strange is the fact that the plugs are identical, one green and one orange. They put the plug from the metering valve to the fpr and vice versa.
I do not understand why I had only those 2 errors and nothing to show me that something is not plugged correctly. The car runner perfectly but dies at idle.
Anyway, now with the correct plugs in the correct way the car is running great, does not die at idle. It still has a lumpy idle but It is from inj no3.
 

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