Audi 100 2.1 K-Jet fuel problem

nokia7799 · 25-10-16, 09:17 PM

Hi,

I have a 1983 Audi 100 Type 44 2144cc with K-Jetronic Fuel Injection. I have never had any problems with the fuel injection system until lately. The car had been laid up (inside) for a number of months and started up as usual. It was quite low (very low!) in petrol and just before i reached the petrol station it cut out. I assumed that i had run out of fuel, which still may be the case. I put in 10 litres and it started up but cut out after 5 minutes and has failed to restart since. There is a good spark and the plugs are dry and in good condition.

I checked for fuel at the fuel filter in the engine bay and there is lots of pressure there which would suggest that fuel pump is ok?. There is also good pressure coming to the fuel distributor unit. but there is no fuel coming to the injectors. I have a spare fuel distributor on another car which i changed and still no fuel coming to the injectors. I subsequently split the original fuel distributor from the lower section and the plungers appears perfect. The long and the short of the story is that i appear to have fuel coming to the fuel distributor but not any further.

Id really appreciate any advice.

Thanks very much.

Regards,

Barry

jack1 · 25-10-16, 09:50 PM

My advice Barry is buy that 100 turbo from your mate down tullamore way👍

nokia7799 · 25-10-16, 09:58 PM

Howya Ivor... Rumour has it that you have it sold!

jack1 · 26-10-16, 05:31 AM

Quote:

Originally Posted by nokia7799

Howya Ivor... Rumour has it that you have it sold!

God no ,,, don't know wether I should either but can't justify 2 ,, will be driving down this Saturday in it 👍

quattrostyle · 29-10-16, 08:10 AM

Get a fuel distributor from a car that is running fine up to the moment you take it off. If the distributor is laid up for a while it will/can result in these kind of problems, either overfuelling or tot little fuel to the injectors.

Groundhog · 29-10-16, 09:21 AM

When you say there is no fuel coming from the injectors - under what conditions? For fuel to flow from the injectors the air flap needs to be raised as it would if the car were being driven. When the car is not running the flap is at rest and the metering slots within the fuel distributor are closed. If you have system pressure at the meter head and there is no fuel at the injectors when the air plate is lifted then the fault must be in the meter head. The fact you were low on fuel suggests you may have drawn dirt but this seldom results in a total failure. Also do not assume that some perceived pressure at the meter head is adaquate pressure, ideally this needs measuring.

Hanuman · 29-10-16, 10:01 AM

As above.

its relatively simple to check fuel delivery, just make sure you're prepared.

-is the fuel pump actually working? Find the relay for the pump supply, and bypass temporarily. Run the pump, and pump fuel from the supply line into a container. Ball park fuel flow on the quattro being about 900ml in 30seconds
-with the air metering flap raised (under the rubber dome), is any fuel coming from the injectors? Pulling the injectors out is a little awkward, physically, but they're only retained by o-rings. This time, pumping fuel into 5 equal size glass containers (large coffee jars, glass beer/drink bottles, etc) gives a good idea about even delivery, and spray pattern.

nokia7799 · 30-10-16, 12:13 AM

Thanks for all your help guys... I subsequently changed the fuel filter as it hadnt been changed in a long time and in case i had drawn muck up from the tank as a result of running out of petorl. I manually pulled up the air flow flap and got petrol coming to the injectors. So it looks like that even though there was what appeared to be good pressure coming to the fuel filter and fuel distributor intake, it was down as a result of a partial blockage in the fuel filter... More simple than i thought really...

I really appreciate all of your advice and help. Its also good to know that i have a spare working fuel distributor....

Thanks again for all your help.

DETROITPISTON · 30-10-16, 04:47 AM

Quote:

Originally Posted by nokia7799

Thanks for all your help guys... I subsequently changed the fuel filter as it hadnt been changed in a long time and in case i had drawn muck up from the tank as a result of running out of petorl. I manually pulled up the air flow flap and got petrol coming to the injectors. So it looks like that even though there was what appeared to be good pressure coming to the fuel filter and fuel distributor intake, it was down as a result of a partial blockage in the fuel filter... More simple than i thought really...

I really appreciate all of your advice and help. Its also good to know that i have a spare working fuel distributor....

Thanks again for all your help.

Ive just read this thread for the first time and that's exactly what i would've suggested. My guess is the fresh intake of petrol has cleared rust/debris which has developed on the tank walls due to standing while low. Seen it quite a few times.

29-10-16, 10:01 AM	#7
Hanuman Trickster Classic Audi Club Member Join Date: May 2009 Location: Heckling from the cheap seats, Phnom Penh, KoW Posts: 7,006	As above. its relatively simple to check fuel delivery, just make sure you're prepared. -is the fuel pump actually working? Find the relay for the pump supply, and bypass temporarily. Run the pump, and pump fuel from the supply line into a container. Ball park fuel flow on the quattro being about 900ml in 30seconds -with the air metering flap raised (under the rubber dome), is any fuel coming from the injectors? Pulling the injectors out is a little awkward, physically, but they're only retained by o-rings. This time, pumping fuel into 5 equal size glass containers (large coffee jars, glass beer/drink bottles, etc) gives a good idea about even delivery, and spray pattern. __________________ I wish they would keep the damned Chinese away now that I can go home, so that I can enjoy Fish amok and a draught Angkor

25-10-16, 09:50 PM	#2
jack1 4 ring whore! Classic Audi Club Member Join Date: Apr 2009 Posts: 2,319	My advice Barry is buy that 100 turbo from your mate down tullamore way👍

25-10-16, 09:58 PM	#3
nokia7799 Grown up member Join Date: Jul 2011 Location: Mayo, Ireland Posts: 56	Howya Ivor... Rumour has it that you have it sold!

29-10-16, 08:10 AM	#5
quattrostyle 4 ring whore! Classic Audi Club Member Join Date: Feb 2010 Posts: 2,188	Get a fuel distributor from a car that is running fine up to the moment you take it off. If the distributor is laid up for a while it will/can result in these kind of problems, either overfuelling or tot little fuel to the injectors.

29-10-16, 09:21 AM	#6
Groundhog Grown up member Join Date: Nov 2009 Posts: 143	When you say there is no fuel coming from the injectors - under what conditions? For fuel to flow from the injectors the air flap needs to be raised as it would if the car were being driven. When the car is not running the flap is at rest and the metering slots within the fuel distributor are closed. If you have system pressure at the meter head and there is no fuel at the injectors when the air plate is lifted then the fault must be in the meter head. The fact you were low on fuel suggests you may have drawn dirt but this seldom results in a total failure. Also do not assume that some perceived pressure at the meter head is adaquate pressure, ideally this needs measuring.

30-10-16, 12:13 AM	#8
nokia7799 Grown up member Join Date: Jul 2011 Location: Mayo, Ireland Posts: 56	Thanks for all your help guys... I subsequently changed the fuel filter as it hadnt been changed in a long time and in case i had drawn muck up from the tank as a result of running out of petorl. I manually pulled up the air flow flap and got petrol coming to the injectors. So it looks like that even though there was what appeared to be good pressure coming to the fuel filter and fuel distributor intake, it was down as a result of a partial blockage in the fuel filter... More simple than i thought really... I really appreciate all of your advice and help. Its also good to know that i have a spare working fuel distributor.... Thanks again for all your help.