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hamma
15-04-2010, 08:36 AM
good morning everybody

yesterday, my 1.9Tdi A6 (C4) engine started kicking. it was like the fuel cut off.
is it due to air presence in the fuel circuit? how can the pump be purged?

thank you

hamma
15-04-2010, 03:48 PM
please, i need your help

Peter D
16-04-2010, 07:55 AM
Please provide the engine code.. Once it it running I do not think air is the problem but if it is a PD engine then I suspect you may va ve a head cable issue. Please provide a better description of the problem. Is it random, cyclic, oftem, only when cold, what. Regards Peter

hamma
16-04-2010, 10:37 AM
thank you Peter D. for your answer.

My engine is the 1Z. the kicks start after 7 to 10 Km and only when driving at 60Km/h and above. no kicks come up when driving at lower speeds. engine idle speed is stable, engine starts in a normal way, i have a little bit of blue smoke which goes away after some kms ( iguess when the engine gets warm). the kicks' strenth is variable from small to very hard and they are present when the engine is warm. i don't drive until i get 60° in the coolant.

is it bad :confused: ?

Peter D
16-04-2010, 10:57 AM
OK IZ was fitted to late 90's C4's. Can you describe the kicking. Is it just one pot missing of ydo you think the engine is being turned off for a short period, thus the big kick. Regards Peter

hamma
16-04-2010, 11:23 AM
It is the 1Z/AHU engine of 1996, like the one installed on the Golf III 1.9 TDI. it is the same engine, only layout has changed.

Peter D
16-04-2010, 11:24 AM
Check the wiring to the fuel cut off valve as the rear of the pump. Why is only does this above 60kph is odd. As you mention kph and km them I assume you are not in the UK. Regards Peter

hamma
16-04-2010, 11:39 AM
yes am not in the UK,

i already checked that valve. it is ok. the voltage is 11-12.5V. it shouldn't be the cause. i tryed to simulate the fuel cut off when running and i turned the engine off the on again quickly but it wasnt that hard as the kicks. i found somewhere that the actuator may cause such problems but it shuld cause the idle speed to fluctuate which is not in my case. what do you think

Peter D
16-04-2010, 12:20 PM
Remove the vacuum pipe to the turbo and go for a run to see if the probel goes away. You may have a faulty turbo actuator solenoid. I would not rule out a EGR valve problem but I do not see how this would cause big kicks. Is it really speed related or is it RPM related. Regards Peter

hamma
16-04-2010, 12:56 PM
ok i ll try and let you know. as i know, EGR problems may cause power loss rather than engine kicking.

i don't know if the speed is an esencial element in this problem, but i don't exclude the RPM factor eventhough i don't get kicked under 60Km/h, or at least, kicks are insignificant.

Thank you peter

Peter D
17-04-2010, 03:21 PM
This is a manual gearbox car isn't it. Regards Peter

hamma
19-04-2010, 09:24 AM
good morning,

sorry for the delay, i was out all the weekend :)

yes, it is a manual gearbox, by the way, can i install a 6 gears gearbox on this model?

Peter D
19-04-2010, 10:27 AM
Is it rpm sensitive or mph sensitive. If it really does kick harder then turning the fuel off it could be a serious injection timing issue. You will have to remind me of your engine code. Have you had a code read done. Regards Peter

hamma
19-04-2010, 11:50 AM
my engine code is 1Z (AHU engine code is written on a plate in the spare wheel compartment)
actually, yesterday i have got a new symptome for a while than went away. it was an unstable idle rpm. The kicks don't start immidiately when i start the car, but after a few kilometers. the unstable idle speed was there for few minutes and went away. the kicks have decreased since this morning. i will need to be sure this afternoon on my way back to home.

kicks+unstable idle rpm are most likely to be actuator related. need just to confirm before i make a surgery to my injection pump :(

hamma
19-04-2010, 11:53 AM
Peter, to answer your question, it is RPM related and NOT speed related, but it will take me 15 mins of driving (sometimes more, sometimes less) to get kicked in the back !!

hamma
20-04-2010, 08:56 AM
Hi, am here again!
well, the going back trip was really painful! i have a broken engine mount so when it kicks, the engine or the gearbox hits the car body and am afraid that i finish with a cracked GB

i think i will open the fuel pump and see if the actuator is durty. hope it will not be as serious as it looks like

Peter D
20-04-2010, 12:52 PM
Does the engine smoke after the Kick. It has been suggested to me that the the pump may be inject excessive fuel ( very excessive ) in a short burst and what you are feeling is the massive increase in compression ratio as the fuel can not all be used up in a single stroke. This can cuase considerable damage. I assume your kick is felt as though the car has been kicked from infront not from behind. Regards Peter

hamma
20-04-2010, 02:38 PM
hi Peter,
i don't see any conciderable smoke behind when it kicks maybe because i don't look behind :P, but you are right about the kick, i feel like it is kicked from infront. although i dont feel any power grow at the instant it kick because if it is overloaded with fuel, it should give some power increasing right?

Peter D
20-04-2010, 03:24 PM
No as there would not be enough air in the cylinder to use up all the fuel. You need to take this car to a deisel specialist. Regards Peter

hamma
20-04-2010, 03:26 PM
Ok thank you Peter
I really appreciate your help

hamma
22-04-2010, 08:43 AM
Hi, am here again with some new updates.
well, to start, my problems are the more and more bigger. the kicks took the place of the normal run and the normal run has become rare until yesterday the engine started shutting down because of a kick at idle run and than a total stop on the highway!

i decided to do whatever is necessery to get it starting again.
with a voltmeter, i measured the voltage at the fuel shut-off valve and i found a very weak feed (4V at best) and some times it goes to 7V and then goes down again to 4,3,2V and even 0V. so i took a wire and i brought the +12V stright to the valve an important spark has been thrown and the car wouldn't start again. i fixed the +12V wire on the valve after removing its original wire and than the car started again, but with a poor engine performance. the engine is getting hot quickly

So the question is: have i damaged my caculator? have i damaged my engine? what could this power loss come from?

hamma
26-04-2010, 08:39 AM
Hi there!!
I have great updates!! problem resolved :))))))))

i ll be short, the problem was a short-circuit at the fuel shut off valve with the fuel injection timing +12V wire and the ground.
result: sporadic power loss at the fuel valve --> engine goes off and goes back on quicly which explains the kicks
the +12V wire (3rd one on the connector) of the injection timing solenoid is the same as the nbr 3 wire of the MAF sensor, the N75, the EGR solenoid, the brake pedal and the cluch pedal switches. this wire (red/white) is directly connected to the engine control unit. i was afraid that this short circuit had caused a damage to the ECU and hopefully, it didn't! there was a fuse (15A) at the ECM compartment under the carpet!

now everything is OK, i only need a new MAF sensor cause mine is completely dead

Hope this helps someone.
have a nice day