Over fueling

sinbin5t · 15-04-17, 03:09 PM

As mentioned in the thread for this car i have an over fueling problem, on the day the car came home it cut out and was very hard to start again. This has now gone on a long long time and i have got to get it sorted.
The car starts first time with the accelerator pedal depressed slightly but it will not just tick over, the plugs are dry but very sooty. Do i just fit the NOS fuel metering head i got and hope for the best or could it be something else, the metering head on it was rebuilt poss 8 years ago.

Desperation is the word now.

vorsprung durch technik · 15-04-17, 03:45 PM

I'd help if i could mate,but i can't.

I don't like to see you struggling with this.
Hope someone can help you out Bruce to get it sorted.

Hanuman · 15-04-17, 03:48 PM

Which car?
Presumably one of the K-jet models?

What have you done, what haven't you done? How have you gone about setting it up?

sinbin5t · 15-04-17, 03:52 PM

Quote:

Originally Posted by vorsprung durch technik

I'd help if i could mate,but i can't.

I don't like to see you struggling with this.
Hope someone can help you out Bruce to get it sorted.

Thanks Mark

sinbin5t · 15-04-17, 03:58 PM

Quote:

Originally Posted by Hanuman

Which car?
Presumably one of the K-jet models?

What have you done, what haven't you done? How have you gone about setting it up?

Hi Mark,
It's the type 43 5T, i don't know how to set it up so have not played with anything, it all just went wrong suddenly, that is all i can say for now.

sinbin5t · 15-04-17, 04:18 PM

I guess i better elaborate a bit, the fuel tank had to be changed (no it wasn't rusty), the fuel pump was full of crap too, the main fuel filter in the engine bay was full of the same crap, all of these things have been replaced but the car still will not tick over and is just filthying the plugs, could this crap have got into the metering head and destroyed it ?

Hanuman · 15-04-17, 04:50 PM

I guess so, although I've not had an issue yet, I know others have, for various reasons. But there are other things to check, too.

To the best of my knowledge, it will largely be the same sort of setup as my WR, albeit with different hoses, etc, for the engine bay layout. Any chance of a picture of the engine bay? A good one, not blurry, or obscure.

I personally find the WR pretty straight forward to setup. I usually do it by ear. 3mm Long Allen key for adjusting mixture, and small screwdriver for the idle air. But the WR has no weird idle controls. I'm not sure about the 100/200, even at that vintage, so most of my thoughts are about the WR.

Bad idle
Is the throttle body clean? Quite often some serious gumming up around the idle screw. Leads to unreliable idle. Sometimes seen as a stall approaching junctions, until it gets to the point of not idling at all.

Wrong Mixture
As you've changed some other components, it may be that you've undone some adjustments made, which previously compensate for a poor performing fuel system.

By ear.
I tweak the idle screw until it idles. Worst case, I just open the throttle Very Very slightly while making a rough setting.
Then I simply adjust the mixture until it peaks in rpm.
i.e. If it's rich, I adjust towards lean until I hear the RPMs rise. Peak is close to ideal mixture. Go further towards lean, and RPM will drop again.
Likewise, if it's too lean, I adjust towards rich. Again, as mixture approaches ideal, the RPMs will rise slightly. Go too rich, and they drop again.

Oddly, if it's running, you can adjust to the point of being hugely rich, without it stalling. However, if you do stop the engine, you can be in a situation where it won't start.

vorsprung durch technik · 15-04-17, 04:52 PM

Spock would say "That does sound logical Captain".

Hanuman · 15-04-17, 04:56 PM

Were these parts replaced due to the rich running issue? Or did the rich running occur after the parts swap?

sinbin5t · 15-04-17, 05:04 PM

Quote:

Originally Posted by Hanuman

I guess so, although I've not had an issue yet, I know others have, for various reasons. But there are other things to check, too.

To the best of my knowledge, it will largely be the same sort of setup as my WR, albeit with different hoses, etc, for the engine bay layout. Any chance of a picture of the engine bay? A good one, not blurry, or obscure.

I personally find the WR pretty straight forward to setup. I usually do it by ear. 3mm Long Allen key for adjusting mixture, and small screwdriver for the idle air. But the WR has no weird idle controls. I'm not sure about the 100/200, even at that vintage, so most of my thoughts are about the WR.

Bad idle
Is the throttle body clean? Quite often some serious gumming up around the idle screw. Leads to unreliable idle. Sometimes seen as a stall approaching junctions, until it gets to the point of not idling at all.

Wrong Mixture
As you've changed some other components, it may be that you've undone some adjustments made, which previously compensate for a poor performing fuel system.

By ear.
I tweak the idle screw until it idles. Worst case, I just open the throttle Very Very slightly while making a rough setting.
Then I simply adjust the mixture until it peaks in rpm.
i.e. If it's rich, I adjust towards lean until I hear the RPMs rise. Peak is close to ideal mixture. Go further towards lean, and RPM will drop again.
Likewise, if it's too lean, I adjust towards rich. Again, as mixture approaches ideal, the RPMs will rise slightly. Go too rich, and they drop again.

Oddly, if it's running, you can adjust to the point of being hugely rich, without it stalling. However, if you do stop the engine, you can be in a situation where it won't start.

On page 73 of the cars thread there is a picture of the engine bay, don't know if it will help though.
The idle screw (i thought it was mixture screw

) was found to be hanging from it's housing by ruud on here, as you may be gathering now things were done to the car by somebody deliberately trying to damage it, should i just change the metering head perhaps and take it from there ?
Sorry for seeming to be vague i am just trying to be careful about what i say before i blurt it all out

15-04-17, 03:48 PM	#3
Hanuman Trickster Classic Audi Club Member Join Date: May 2009 Location: Heckling from the cheap seats, Phnom Penh, KoW Posts: 7,028	Need more info... Which car? Presumably one of the K-jet models? What have you done, what haven't you done? How have you gone about setting it up? __________________ 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

15-04-17, 04:50 PM	#7
Hanuman Trickster Classic Audi Club Member Join Date: May 2009 Location: Heckling from the cheap seats, Phnom Penh, KoW Posts: 7,028	I guess so, although I've not had an issue yet, I know others have, for various reasons. But there are other things to check, too. To the best of my knowledge, it will largely be the same sort of setup as my WR, albeit with different hoses, etc, for the engine bay layout. Any chance of a picture of the engine bay? A good one, not blurry, or obscure. I personally find the WR pretty straight forward to setup. I usually do it by ear. 3mm Long Allen key for adjusting mixture, and small screwdriver for the idle air. But the WR has no weird idle controls. I'm not sure about the 100/200, even at that vintage, so most of my thoughts are about the WR. Bad idle Is the throttle body clean? Quite often some serious gumming up around the idle screw. Leads to unreliable idle. Sometimes seen as a stall approaching junctions, until it gets to the point of not idling at all. Wrong Mixture As you've changed some other components, it may be that you've undone some adjustments made, which previously compensate for a poor performing fuel system. By ear. I tweak the idle screw until it idles. Worst case, I just open the throttle Very Very slightly while making a rough setting. Then I simply adjust the mixture until it peaks in rpm. i.e. If it's rich, I adjust towards lean until I hear the RPMs rise. Peak is close to ideal mixture. Go further towards lean, and RPM will drop again. Likewise, if it's too lean, I adjust towards rich. Again, as mixture approaches ideal, the RPMs will rise slightly. Go too rich, and they drop again. Oddly, if it's running, you can adjust to the point of being hugely rich, without it stalling. However, if you do stop the engine, you can be in a situation where it won't start. __________________ 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

15-04-17, 04:56 PM	#9
Hanuman Trickster Classic Audi Club Member Join Date: May 2009 Location: Heckling from the cheap seats, Phnom Penh, KoW Posts: 7,028	Were these parts replaced due to the rich running issue? Or did the rich running occur after the parts swap? __________________ 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

15-04-17, 03:45 PM	#2
vorsprung durch technik 4 ring whore! Classic Audi Club Member Join Date: Feb 2014 Location: Near Watford. Posts: 7,762	I'd help if i could mate,but i can't. I don't like to see you struggling with this. Hope someone can help you out Bruce to get it sorted.

15-04-17, 04:18 PM	#6
sinbin5t 4 ring whore! Classic Audi Club Member Join Date: Jan 2010 Location: Where a spike points skywards Posts: 12,960	I guess i better elaborate a bit, the fuel tank had to be changed (no it wasn't rusty), the fuel pump was full of crap too, the main fuel filter in the engine bay was full of the same crap, all of these things have been replaced but the car still will not tick over and is just filthying the plugs, could this crap have got into the metering head and destroyed it ?

15-04-17, 04:52 PM	#8
vorsprung durch technik 4 ring whore! Classic Audi Club Member Join Date: Feb 2014 Location: Near Watford. Posts: 7,762	Spock would say "That does sound logical Captain".