80 Quattro KK engine won't start

Mike671 · 24-05-12, 11:13 PM

Right ok it's been sat for awile matey I got it off reckon he last started it one year ago though. Spark is lovely that's all there, compression is nice and strong around 13 bar per cylinder, so I'm guessing it's fuel well you crank it over first time and you have pressure of around 130-140 psi on line out the pump, but no fuel out the metering head on crank, is this correct? the cold start valve spits fuel but it doesn't even hesitate to start. So then I placed fuel pressure guage on line out metering head no pressure on crank, but lift metering head flap slightly first time of cranking you have no pressure let off the key pressure builds to around 30 psi then turn key again and you have around 60 psi. Can someone help me out? As k jet is doing my head in I would love to hear it run :-( and yes it has fresh fuel in it

8690q · 24-05-12, 11:44 PM

Seized fuel pump ?
Not sure how safe it is but I've run 12v right to the pump and it freed it off and the car started.

Mike671 · 24-05-12, 11:47 PM

Pump pumps fuel lovely on crank, pressure on end of line is approx 140 psi so that's working

msh · 25-05-12, 05:30 AM

Putting manometer at the end of the fuel line can do two things - to check if pumps backflow valve doesn't let the fuel back, which isn't important to you currently, and also it can blow apart rubber fuel hoses at the pump

You need to measure system pressure, without interrupting system, if you have such manometer, of course.

Although it would be better to remove main injectors and see what they are doing. And the best way how to get pump running is by shorting two fuel pump relay terminals, because starter sound could prevent you from hearing something

P.S. I'm wondering - KE-jet has small sieve in incoming fuel line bolt, clogging of which could cause interesting things, maybe K-jet has the same?

Mike671 · 25-05-12, 06:45 AM

Yep this also has the small sleeved gauze in the incoming fuel line which I cleaned out but seemed ok anyway, yes my fuel guage was inline which on feed side of meterin head I have around 140 psi, what number is that relay? Also when I come off crank the pump stops running what out of interest keeps the pump running when the engine starts?

Many thanks

90 B2 quattro · 25-05-12, 07:08 AM

Sounds to me like the fuel pump relay, i had the exact same problem, took the relay out and plugged it halfway in and car started, pushed in all the way it would stall at random or not start at all. I took the cover off it and found the solders had come apart on the cicuit board.
Easy fix but bloody frustrating to find the cause. Hope this helps?

urS6 · 26-05-12, 09:19 PM

Only starting problem I ever had with mine was after I pressure washed the engine bay. I presumed the lack of starting was due to some water in the ignition bits, so I dried it thoroughly and let it sit for a day in sunny weather. It still wouldn't start. Then I prodded around and found a vacuum hose had come off. Put it back on and all was well.

Check your hoses (although if you're getting odd fuel pressures, that obviously needs to be sorted out).

Have you tried a small dose of starting fluid? Don't do it too often as apparently its not good for your rings, but it will prove that the spark and compression side of things is OK, leaving fuel as the only culprit.

On the four cars with K-Jetronic that I had, I found it to be a superbly reliable system.

Mike671 · 05-06-12, 05:51 PM

It runs woohoo!!!!

urS6 · 05-06-12, 06:36 PM

What fixed it?

Mike671 · 05-06-12, 06:46 PM

Going right back to basics had compression spark and some fuel so guessed one of these must have been out, after finding where timing marks where found cam advanced around 80 degrees round! Took belt off timed up flicked key fired straight up sounds lovely turned off ready to order new belt!

24-05-12, 11:44 PM	#2
8690q Grown up member Classic Audi Club Member Join Date: Jun 2009 Location: Coalsnaughton Posts: 190	Seized fuel pump ? Not sure how safe it is but I've run 12v right to the pump and it freed it off and the car started.

24-05-12, 11:47 PM	#3
Mike671 Grown up member Join Date: May 2012 Posts: 50	Pump pumps fuel lovely on crank, pressure on end of line is approx 140 psi so that's working

25-05-12, 05:30 AM	#4
msh 4 ring whore! Join Date: Jun 2008 Location: Rucava, Latvija Posts: 3,816	Putting manometer at the end of the fuel line can do two things - to check if pumps backflow valve doesn't let the fuel back, which isn't important to you currently, and also it can blow apart rubber fuel hoses at the pump You need to measure system pressure, without interrupting system, if you have such manometer, of course. Although it would be better to remove main injectors and see what they are doing. And the best way how to get pump running is by shorting two fuel pump relay terminals, because starter sound could prevent you from hearing something P.S. I'm wondering - KE-jet has small sieve in incoming fuel line bolt, clogging of which could cause interesting things, maybe K-jet has the same?

25-05-12, 06:45 AM	#5
Mike671 Grown up member Join Date: May 2012 Posts: 50	Yep this also has the small sleeved gauze in the incoming fuel line which I cleaned out but seemed ok anyway, yes my fuel guage was inline which on feed side of meterin head I have around 140 psi, what number is that relay? Also when I come off crank the pump stops running what out of interest keeps the pump running when the engine starts? Many thanks

25-05-12, 07:08 AM	#6
90 B2 quattro Grown up member Join Date: Mar 2011 Location: Dunedin, NewZealand Posts: 168	Sounds to me like the fuel pump relay, i had the exact same problem, took the relay out and plugged it halfway in and car started, pushed in all the way it would stall at random or not start at all. I took the cover off it and found the solders had come apart on the cicuit board. Easy fix but bloody frustrating to find the cause. Hope this helps?

26-05-12, 09:19 PM	#7
urS6 Grown up member Join Date: May 2010 Location: Worcestershire Posts: 115	Only starting problem I ever had with mine was after I pressure washed the engine bay. I presumed the lack of starting was due to some water in the ignition bits, so I dried it thoroughly and let it sit for a day in sunny weather. It still wouldn't start. Then I prodded around and found a vacuum hose had come off. Put it back on and all was well. Check your hoses (although if you're getting odd fuel pressures, that obviously needs to be sorted out). Have you tried a small dose of starting fluid? Don't do it too often as apparently its not good for your rings, but it will prove that the spark and compression side of things is OK, leaving fuel as the only culprit. On the four cars with K-Jetronic that I had, I found it to be a superbly reliable system.

05-06-12, 05:51 PM	#8
Mike671 Grown up member Join Date: May 2012 Posts: 50	It runs woohoo!!!!

05-06-12, 06:36 PM	#9
urS6 Grown up member Join Date: May 2010 Location: Worcestershire Posts: 115	What fixed it?

05-06-12, 06:46 PM	#10
Mike671 Grown up member Join Date: May 2012 Posts: 50	Going right back to basics had compression spark and some fuel so guessed one of these must have been out, after finding where timing marks where found cam advanced around 80 degrees round! Took belt off timed up flicked key fired straight up sounds lovely turned off ready to order new belt!