| Author |
Message |
cp
Guest
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 Posted:
Sun Sep 04, 2005 8:12 am Post subject:
'86 5K TQ don't want to start after air and fuel filter chan |
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Hi,
My '86 5K TQ don't want to start after an air and fuel filter change. I did get it started twice by cranking but as soon as it
starts up it will die if I don't hold the gas. It drives great but dies upon attempting to idle. It starts no problem when the car
is moving and is put in gear. What could be the problem? Could it be air in the system? What is the fuel filter change procedure,
does the system have to be bled afterwards? Also, before I touched the car today, when turning off the car when the engine is warm,
the car won't start again for 5-8 minutes, after that it starts no problem. Though it never has any problems starting when the car
is moving and is put in gear. Cold starts are immediate, though not anymore of course.
Thank you in advance for any help!
cp
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Tony
Guest
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| Posted:
Mon Sep 05, 2005 12:14 am Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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It sounds like you have a vacuum leak.
Or, you may have disconnected the wires to the throttle body for the switch that
controls the ISV.
No special bleeding procedure for filter changes.
Tony
Current: 98.5 A4 1.8TQM
Previous: four T44s '84 - '91
cp wrote:
| Quote: | Hi,
My '86 5K TQ don't want to start after an air and fuel filter change. I did get it started twice by cranking but as soon as it
starts up it will die if I don't hold the gas. It drives great but dies upon attempting to idle. It starts no problem when the car
is moving and is put in gear. What could be the problem? Could it be air in the system? What is the fuel filter change procedure,
does the system have to be bled afterwards? Also, before I touched the car today, when turning off the car when the engine is warm,
the car won't start again for 5-8 minutes, after that it starts no problem. Though it never has any problems starting when the car
is moving and is put in gear. Cold starts are immediate, though not anymore of course.
Thank you in advance for any help!
cp
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cp
Guest
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| Posted:
Tue Sep 06, 2005 8:12 am Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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| Quote: | It sounds like you have a vacuum leak.
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Vacuum leak? Are there any other tell-tale symptoms I should look for? Today, after getting back from a trip (in another car) I went
to start it up after letting it sit for a couple of days and it started right up, idled fine and the problem started again a couple
of minutes later.
| Quote: | Or, you may have disconnected the wires to the throttle body for the switch that controls the ISV.
|
You know, I might have nudged something. Will take a look at the factory manual what it could be.
Thank you!
cp
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Tony
Guest
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| Posted:
Wed Sep 07, 2005 8:13 am Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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Here's a Q&D vacuum leak test:
- engine idling
- remove oil dipstick
- engine should stumble and run poorly. Replace dipstick.
- open oil filler cap
- engine should die
If these conditions do not occur you have a vacuum leak that is either
intermittent or being compensated for by other adjustments and needs to be
coppected.
Damn, these Audi's are so much fun :-)
cp wrote:
| Quote: | It sounds like you have a vacuum leak.
Vacuum leak? Are there any other tell-tale symptoms I should look for? Today, after getting back from a trip (in another car) I went
to start it up after letting it sit for a couple of days and it started right up, idled fine and the problem started again a couple
of minutes later.
Or, you may have disconnected the wires to the throttle body for the switch that controls the ISV.
You know, I might have nudged something. Will take a look at the factory manual what it could be.
Thank you!
cp
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Tony
Guest
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| Posted:
Thu Sep 08, 2005 8:12 am Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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Shokan usually has a $125 US fuel pump special on ebay. The pump is Pierburg and
is good. I used one in a '91 100qm. Quiet and works. What more can one ask for.
Shokan increases the price if you order on the phone. Gotta use ebay. Not sure
how that would work shipping to Canada.
cp wrote:
| Quote: | Here's a Q&D vacuum leak test:
- engine idling
- remove oil dipstick
- engine should stumble and run poorly. Replace dipstick.
- open oil filler cap
- engine should die
If these conditions do not occur you have a vacuum leak that is either intermittent or being compensated for by other adjustments
and needs to be coppected.
Damn, these Audi's are so much fun :-)
Ah, so this is normal, I was wondering why the car would die when the oil filler cap was removed.
My mechanic friend however checked it out and said that the fuel pump is bad, says fuel stops coming from the (losened) fuel filter
connection before the car dies, ahhhhhhhhh I don't want to waste money on this!! What's a good place to get a fuel pump assembly?
Here in Canada the fuel pickup, fuel pump and wire harness costs about $350USD, can't I just get the fuel pump?
cp
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cp
Guest
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| Posted:
Thu Sep 08, 2005 8:12 am Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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| Quote: | Here's a Q&D vacuum leak test:
- engine idling
- remove oil dipstick
- engine should stumble and run poorly. Replace dipstick.
- open oil filler cap
- engine should die
If these conditions do not occur you have a vacuum leak that is either intermittent or being compensated for by other adjustments
and needs to be coppected.
Damn, these Audi's are so much fun :-)
|
Ah, so this is normal, I was wondering why the car would die when the oil filler cap was removed.
My mechanic friend however checked it out and said that the fuel pump is bad, says fuel stops coming from the (losened) fuel filter
connection before the car dies, ahhhhhhhhh I don't want to waste money on this!! What's a good place to get a fuel pump assembly?
Here in Canada the fuel pickup, fuel pump and wire harness costs about $350USD, can't I just get the fuel pump?
cp |
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cp
Guest
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| Posted:
Fri Sep 09, 2005 8:13 am Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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hmmmmmm but don't I need the whole assembly with it? (fuel pick up and wires)
cp
| Quote: | Shokan usually has a $125 US fuel pump special on ebay. The pump is Pierburg and is good. I used one in a '91 100qm. Quiet and
works. What more can one ask for.
Shokan increases the price if you order on the phone. Gotta use ebay. Not sure how that would work shipping to Canada.
cp wrote:
Here's a Q&D vacuum leak test:
- engine idling
- remove oil dipstick
- engine should stumble and run poorly. Replace dipstick.
- open oil filler cap
- engine should die
If these conditions do not occur you have a vacuum leak that is either intermittent or being compensated for by other adjustments
and needs to be coppected.
Damn, these Audi's are so much fun :-)
Ah, so this is normal, I was wondering why the car would die when the oil filler cap was removed.
My mechanic friend however checked it out and said that the fuel pump is bad, says fuel stops coming from the (losened) fuel
filter connection before the car dies, ahhhhhhhhh I don't want to waste money on this!! What's a good place to get a fuel pump
assembly? Here in Canada the fuel pickup, fuel pump and wire harness costs about $350USD, can't I just get the fuel pump?
cp |
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Steve Sears
Guest
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| Posted:
Fri Sep 09, 2005 6:44 pm Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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cp,
No, you just need the pump. The wires just bolt on. There's lots written
up on Audifans and (probably) Audiworld about replacing the pump - most
important thing, aside from the warnings about gas fumes being
dangerous/explosive/etc.etc. is that you make sure that the orientation of
the connections to the pump remain unchanged - otherwise your gas gauge will
stop reading when the float arm hangs up on the wires/hose. BTDT numerous
times - I gave up.
Cheers!
Steve Sears
1987 Audi 5kTQ - fuel gauge won't read the last 1/8th of a tank
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)
"cp" <asdf@asdf.com> wrote in message
news:quaUe.166626$wr.119945@clgrps12...
| Quote: | hmmmmmm but don't I need the whole assembly with it? (fuel pick up and
wires)
cp
Shokan usually has a $125 US fuel pump special on ebay. The pump is
Pierburg and is good. I used one in a '91 100qm. Quiet and
works. What more can one ask for.
Shokan increases the price if you order on the phone. Gotta use ebay.
Not sure how that would work shipping to Canada.
cp wrote:
Here's a Q&D vacuum leak test:
- engine idling
- remove oil dipstick
- engine should stumble and run poorly. Replace dipstick.
- open oil filler cap
- engine should die
If these conditions do not occur you have a vacuum leak that is either
intermittent or being compensated for by other adjustments
and needs to be coppected.
Damn, these Audi's are so much fun :-)
Ah, so this is normal, I was wondering why the car would die when the
oil filler cap was removed.
My mechanic friend however checked it out and said that the fuel pump
is bad, says fuel stops coming from the (losened) fuel
filter connection before the car dies, ahhhhhhhhh I don't want to waste
money on this!! What's a good place to get a fuel pump
assembly? Here in Canada the fuel pickup, fuel pump and wire harness
costs about $350USD, can't I just get the fuel pump?
cp
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cp
Guest
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| Posted:
Sat Sep 10, 2005 8:13 am Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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Hi Steve!
Always good to hear from you!
Well, my mechanic friend took a look at the car today and says that the fuel pump works fine. He took off the fuel pressure
accumulator and a load of RUST came out (why is a "fuel pressure accumulator" needed?? (Couldn't they build up fuel pressure by
activating the fuel pump before ignition?). Should I flush out the gas tank? Supposedly, if the "fuel pressure accumulator" was the
problem then I would have trouble starting the car up after it's been sitting over night, but the car starts fine, idles OK for a
couple of minutes and then dies. And THEN I have trouble starting it, though it starts no problem when thrown into gear when the car
is moving. Any idear what this could be?
Thank you!
cp
| Quote: | cp,
No, you just need the pump. The wires just bolt on. There's lots written
up on Audifans and (probably) Audiworld about replacing the pump - most
important thing, aside from the warnings about gas fumes being
dangerous/explosive/etc.etc. is that you make sure that the orientation of
the connections to the pump remain unchanged - otherwise your gas gauge will
stop reading when the float arm hangs up on the wires/hose. BTDT numerous
times - I gave up.
Cheers!
Steve Sears
1987 Audi 5kTQ - fuel gauge won't read the last 1/8th of a tank
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply) |
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Tony
Guest
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| Posted:
Sat Sep 10, 2005 7:57 pm Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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|
Sounds like you have a problem with the coating on the inside of the fuel tank
falling off and clogging the fuel pump's intake screen. Common problem for pre
'90 T44s
Check history on Audiworld T44 forum for correction:
http://forums.audiworld.com/v8/
The recommended Audi fix is to cut off the intake screen from the fuel pump and
then replace the fuel filter.
cp wrote:
| Quote: | Hi Steve!
Always good to hear from you!
Well, my mechanic friend took a look at the car today and says that the fuel pump works fine. He took off the fuel pressure
accumulator and a load of RUST came out (why is a "fuel pressure accumulator" needed?? (Couldn't they build up fuel pressure by
activating the fuel pump before ignition?). Should I flush out the gas tank? Supposedly, if the "fuel pressure accumulator" was the
problem then I would have trouble starting the car up after it's been sitting over night, but the car starts fine, idles OK for a
couple of minutes and then dies. And THEN I have trouble starting it, though it starts no problem when thrown into gear when the car
is moving. Any idear what this could be?
Thank you!
cp
cp,
No, you just need the pump. The wires just bolt on. There's lots written
up on Audifans and (probably) Audiworld about replacing the pump - most
important thing, aside from the warnings about gas fumes being
dangerous/explosive/etc.etc. is that you make sure that the orientation of
the connections to the pump remain unchanged - otherwise your gas gauge will
stop reading when the float arm hangs up on the wires/hose. BTDT numerous
times - I gave up.
Cheers!
Steve Sears
1987 Audi 5kTQ - fuel gauge won't read the last 1/8th of a tank
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)
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cp
Guest
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| Posted:
Sat Sep 10, 2005 11:18 pm Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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| Quote: | Sounds like you have a problem with the coating on the inside of the fuel tank falling off and clogging the fuel pump's intake
screen. Common problem for pre '90 T44s
Check history on Audiworld T44 forum for correction:
http://forums.audiworld.com/v8/
The recommended Audi fix is to cut off the intake screen from the fuel pump and then replace the fuel filter.
|
Yeh, I was thinking of flushing the tank (with my mechanic friend's help of course). Is there only one filter?
Also, what could possibly go wrong with a fuel accumulator? Isn't that a relatively simple part?
Thank you Tony for your help!
cp |
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Tony
Guest
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| Posted:
Sun Sep 11, 2005 2:59 am Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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Flushing tank is fine but the pealing crud will continue so cutting the screen
from the fuel pump is important. Once that is done the crud will be trapped by
the fuel filter in engine compartment (on Passenger side fender). You will need
to change the filter more often as a result.
If the fuel accumulator check valve goes bad then you will need to crank the
starter for a longer time when starting to build pressure. I am not sure but if
the accumulator is completely non-functional you may have a no-start condition
result.
May want to check history at Audiworld on that.
Good luck.
cp wrote:
| Quote: | Sounds like you have a problem with the coating on the inside of the fuel tank falling off and clogging the fuel pump's intake
screen. Common problem for pre '90 T44s
Check history on Audiworld T44 forum for correction:
http://forums.audiworld.com/v8/
The recommended Audi fix is to cut off the intake screen from the fuel pump and then replace the fuel filter.
Yeh, I was thinking of flushing the tank (with my mechanic friend's help of course). Is there only one filter?
Also, what could possibly go wrong with a fuel accumulator? Isn't that a relatively simple part?
Thank you Tony for your help!
cp
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cp
Guest
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| Posted:
Mon Sep 12, 2005 3:32 am Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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| Quote: | Flushing tank is fine but the pealing crud will continue so cutting the screen from the fuel pump is important. Once that is done
the crud will be trapped by the fuel filter in engine compartment (on Passenger side fender). You will need to change the filter
more often as a result.
|
Yeh, took care of that.
| Quote: | If the fuel accumulator check valve goes bad then you will need to crank the starter for a longer time when starting to build
pressure. I am not sure but if the accumulator is completely non-functional you may have a no-start condition result.
|
Well, we bypassed the fuel accumulator and haven't noticed anything different, BUT the problem is SOLVED, turns out the hose from
the air cleaner to the intake was severed, now there's no problem at all. It starts fine any time and idles fine. Whew! Glad I
didn't have to replace anything, what a learning experience, I think I'll understand the whole fuel process soon! :-)
cp |
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Steve Sears
Guest
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| Posted:
Tue Sep 13, 2005 6:12 pm Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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cp,
Good to hear that you solved the problem. You might want to check all the
underhood hoses for leaks as well - heat and rubber don't really get along
too well. One method for checking for leaks is to make a cap for the
intake, and then get a regulator and supply compressed air at a pressure at
or slightly below the max boost pressure the ECU transducer will allow (say,
at 1.6 bar - sorry for the units) and then listen for leaks - or have some
real fun, and dump a bucket of soapy water on the engine compartment and
look for bubbles - kids enjoy this method and it makes car diagnosis fun for
the whole family ;-)
The accumulator is, in essence, a pressure tank for the fuel system, you may
liken it to a device that deals with water hammer in pipes. Although I have
never dissected one, I did replace the one in my 5ktq once and it sounds
like there's a large spring in there. My guess is that it cushions the pump
from the rapid changes in fuel delivery. I do believe that the check valve
Tony is referring to is mounted just above the pump in the tank.
Good luck on understanding the fuel process.....if you really get into it,
you'll realize why some have ditched the whole CIS stuff and gone with
things like 034EFI and such.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)
"cp" <asdf@asdf.com> wrote in message news:ag2Ve.236201$HI.1915@edtnps84...
| Quote: | Flushing tank is fine but the pealing crud will continue so cutting the
screen from the fuel pump is important. Once that is done
the crud will be trapped by the fuel filter in engine compartment (on
Passenger side fender). You will need to change the filter
more often as a result.
Yeh, took care of that.
If the fuel accumulator check valve goes bad then you will need to crank
the starter for a longer time when starting to build
pressure. I am not sure but if the accumulator is completely
non-functional you may have a no-start condition result.
Well, we bypassed the fuel accumulator and haven't noticed anything
different, BUT the problem is SOLVED, turns out the hose from
the air cleaner to the intake was severed, now there's no problem at all.
It starts fine any time and idles fine. Whew! Glad I
didn't have to replace anything, what a learning experience, I think I'll
understand the whole fuel process soon! :-)
cp
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Steve Sears
Guest
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| Posted:
Tue Sep 13, 2005 6:15 pm Post subject:
Re: '86 5K TQ don't want to start after air and fuel filter |
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cp,
I just realized that that pressure is absolute - so if you have a regulator
with a gauge, then you'd set the pressure at 0.6 bar on the gauge (~ 1.6 bar
on the dash)
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)
"Steve Sears" <steve.sears@SHOESsoil-mat.on.ca> wrote in message
news:bjAVe.1745$6Z1.405226@news20.bellglobal.com...
| Quote: | cp,
Good to hear that you solved the problem. You might want to check all the
underhood hoses for leaks as well - heat and rubber don't really get along
too well. One method for checking for leaks is to make a cap for the
intake, and then get a regulator and supply compressed air at a pressure
at
or slightly below the max boost pressure the ECU transducer will allow
(say,
at 1.6 bar - sorry for the units) and then listen for leaks - or have some
real fun, and dump a bucket of soapy water on the engine compartment and
look for bubbles - kids enjoy this method and it makes car diagnosis fun
for
the whole family ;-)
The accumulator is, in essence, a pressure tank for the fuel system, you
may
liken it to a device that deals with water hammer in pipes. Although I
have
never dissected one, I did replace the one in my 5ktq once and it sounds
like there's a large spring in there. My guess is that it cushions the
pump
from the rapid changes in fuel delivery. I do believe that the check
valve
Tony is referring to is mounted just above the pump in the tank.
Good luck on understanding the fuel process.....if you really get into it,
you'll realize why some have ditched the whole CIS stuff and gone with
things like 034EFI and such.
Cheers!
Steve Sears
1987 Audi 5kTQ
1980 Audi 5k
1962 and '64 Auto Union DKW Junior deLuxes
(SPAM Blocker NOTE: Remove SHOES to reply)
"cp" <asdf@asdf.com> wrote in message
news:ag2Ve.236201$HI.1915@edtnps84...
Flushing tank is fine but the pealing crud will continue so cutting
the
screen from the fuel pump is important. Once that is done
the crud will be trapped by the fuel filter in engine compartment (on
Passenger side fender). You will need to change the filter
more often as a result.
Yeh, took care of that.
If the fuel accumulator check valve goes bad then you will need to
crank
the starter for a longer time when starting to build
pressure. I am not sure but if the accumulator is completely
non-functional you may have a no-start condition result.
Well, we bypassed the fuel accumulator and haven't noticed anything
different, BUT the problem is SOLVED, turns out the hose from
the air cleaner to the intake was severed, now there's no problem at
all.
It starts fine any time and idles fine. Whew! Glad I
didn't have to replace anything, what a learning experience, I think
I'll
understand the whole fuel process soon! :-)
cp
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