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Originally posted by hunker7
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Not likely. It's brand new. -
doesn't mean it can't be kaput.
'93 Audi 100 Avant - R.I.P
'92 Audi UrS4 Avant - SOLD
'93 Audi UrS4 Avant LPGComment
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I had a dead lambda on this car once, it's completely different... I had no power and the car was very lazy. Under light load it stuttered while the lambda was cold.Last edited by RichLV; 26 April 2016, 08:53.Comment
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In that case try clearing codes, and then go for a drive, and see what comes up then.Originally posted by RichLV View Post
http://wiki.ross-tech.com/wiki/index.php/00561'93 Audi 100 Avant - R.I.P
'92 Audi UrS4 Avant - SOLD
'93 Audi UrS4 Avant LPGComment
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Does it start any quicker if you give it a little throttle while cranking? Just thinking there may not be enough air getting to engine via ISV on startup...Comment
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It did start faster once I touched the pedal.Originally posted by mike74 View Post
The disconnected N80 did not help. What other options could I have? I'll probably pull the rail out on Saturday, check if the injectors aren't leaking. And I'll fit a fuel pressure gauge as well.
Presumably I have a leaking injector/injectors, what would be the symptoms? Black smoke, fuel stink, reduced boost, sooty spark plugs, increased fuel consumption?
Gave it WOT run in third, goes like hell, almost 1,1 bar on the gauge.Last edited by RichLV; 26 April 2016, 07:48.Comment
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It's possible that N71 is sticking when cold, and when it heats up it works properly. Try cleaning it with WD40, don't use carb cleaner as that can dry it out.Originally posted by RichLV View Post
When I had leaking injector, I got blue smoke on start up, and when it failed while driving I also had massive blue smoke coming outta back
So if it is leaking, you will get some kind of smoke outta back, as I assume you don't have oil leaks after such a rebuild 
Does it run as it should then? Because I am getting full boost currently, but she isn't running correctly.
'93 Audi 100 Avant - R.I.P
'92 Audi UrS4 Avant - SOLD
'93 Audi UrS4 Avant LPGComment
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N71? I can remove and clean it, but that's about it. Also, I can struggle starting a very cold car, start it, shut it off immediately and start it again immediately with no issues. N71 is still cold at the time.Originally posted by hunker7 View PostIt's possible that N71 is sticking when cold, and when it heats up it works properly. Try cleaning it with WD40, don't use carb cleaner as that can dry it out.
When I had leaking injector, I got blue smoke on start up, and when it failed while driving I also had massive blue smoke coming outta back So if it is leaking, you will get some kind of smoke outta back, as I assume you don't have oil leaks after such a rebuild
Does it run as it should then? Because I am getting full boost currently, but she isn't running correctly.
I have no smoke, no smell, no leaks. But I strongly believe that something is wrong with the startup mixture. It starts easier with throttle pressed, as it let's additional air inside the manifold it leads me to believe that it evens out the mixture.
It's either too rich or too lean on startup. I'll have the fuel gauge installed on Saturday and I'll monitor for pressure changes in the fuel rail. I'll also swap the FPR, I don't trust the one I have now.
It runs like a dream once it starts. The torque is very nice, a kick in the back once it comes on boost and overall very nice feeling considering it's stock save for the exhaust manifold. The idle is rock solid around 900 rpm. It wobbles and fluctuates idle shortly after the start, but once it normalizes the mixture the issues just vanish.
I'm thinking like this -> leaking injector, bad FPR or pump check valve will lead to a pressure drop in the fuel rail, right? Priming the pump directly from the relay does not help. Disconnecting N80 for the case of uncontrolled fuel vapor leaking does not help. What's left?Last edited by RichLV; 26 April 2016, 11:29.Comment
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To test if its too rich (or not enough air) on startup, try pulling a vacuum pipe or two off before you go to crank it. The extra air might be enough to start it properly and point you in the right direction....
By the sound of things giving the ISV a good clean wont do any harm either wayComment
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The small ones, which are connected to BPV, FPR, etc.?Originally posted by mike74 View PostTo test if its too rich (or not enough air) on startup, try pulling a vacuum pipe or two off before you go to crank it. The extra air might be enough to start it properly and point you in the right direction....
By the sound of things giving the ISV a good clean wont do any harm either wayComment
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Don't remove the one that goes to FPR, but you can remove one for BPV and 2nd one at the back of mani.Originally posted by RichLV View Post'93 Audi 100 Avant - R.I.P
'92 Audi UrS4 Avant - SOLD
'93 Audi UrS4 Avant LPGComment
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Yup, or even pull the ISV so its almost out of the hose underneath itComment
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Fixed it! Fuel pressure regulator was at fault. Swapped it for a new Bosch unit and now it starts with half of a key turn.
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Nice oneOriginally posted by RichLV View PostFixed it! Fuel pressure regulator was at fault. Swapped it for a new Bosch unit and now it starts with half of a key turn. I need to dig out my low mileage one and stick that it 
'93 Audi 100 Avant - R.I.P
'92 Audi UrS4 Avant - SOLD
'93 Audi UrS4 Avant LPGComment
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Good for you. That did NOT work for me.Originally posted by RichLV View PostFixed it! Fuel pressure regulator was at fault. Swapped it for a new Bosch unit and now it starts with half of a key turn.
RS2'd 93 UrS4 5 spd sedan
94 UrS4 V8 6 spd manual avantComment
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