Super rich on cold startup
12-29-2012, 12:32 AM
#1
Burning Brakes
Thread Starter
Super rich on cold startup
Earlier in the year when it was warmer - the car would start up fine, idle smooth - all that good stuff. But the last few times I've driven it - it was pretty cold out (for an old 911 Turbo :-) By cold I'm talking when it's mid 30's, low 40's F outside. It runs sooo rich, idles low and rough, some visible exhaust smoke, and _noxious_ exhaust fumes. For several minutes. Holy cow.
Is this just due to a "worn" WUR? I am planning to have BL do my WUR - will this solve the issue?
Other than that car seems to be running fine....
It's cold and wintery out - It's torture to be watching stupid youtube vids.. reading about cool projects...I want to go drive!!!!
Brandon
'91 911 Turbo
'01 Audi S4
Is this just due to a "worn" WUR? I am planning to have BL do my WUR - will this solve the issue?
Other than that car seems to be running fine....
It's cold and wintery out - It's torture to be watching stupid youtube vids.. reading about cool projects...I want to go drive!!!!
Brandon
'91 911 Turbo
'01 Audi S4
Last edited by urquattro20Vt; 12-29-2012 at 12:04 PM.
12-29-2012, 10:04 AM
#2
Rennlist Member
Brandon,
Go to Ebay and buy yourself a Bosch CIS pressure test kit: http://www.ebay.com/itm/Basic-CIS-Fu...671539&vxp=mtr I have this kit and it does the job.
Your going to need it for the Leask wur anyway. Then you can test your wur and see if you are in spec. The other possibility is that the cold injector valve is no longer spraying but dumping fuel into the manifold.
Go to Ebay and buy yourself a Bosch CIS pressure test kit: http://www.ebay.com/itm/Basic-CIS-Fu...671539&vxp=mtr I have this kit and it does the job.
Your going to need it for the Leask wur anyway. Then you can test your wur and see if you are in spec. The other possibility is that the cold injector valve is no longer spraying but dumping fuel into the manifold.
12-29-2012, 07:13 PM
#3
i would suggest two extensions on that pressure kit, a gate valve and a pressure pump.
you`ll need the valve to check system pressure additional to cold and warm control pressure. more important is a handpump for checking the full throttle enrichment, activated by boost pressure.
btw, the oe wur is adjustable. the steel membrane is under pressure of a double spring. the inner spring is activated by a diaphragm under boost pressure. the basis of that inner spring is adjustable due to a fine thread srew.
the ft enrichment affects the afr above 0,3 bar boost, so this is the mode that is more important than partial load.
in addition to what Paul wrote regarding that cold start issue i would check the temp switch which controls the cold start valve. leak air is another possible cause of the problem.
fritz
you`ll need the valve to check system pressure additional to cold and warm control pressure. more important is a handpump for checking the full throttle enrichment, activated by boost pressure.
btw, the oe wur is adjustable. the steel membrane is under pressure of a double spring. the inner spring is activated by a diaphragm under boost pressure. the basis of that inner spring is adjustable due to a fine thread srew.
the ft enrichment affects the afr above 0,3 bar boost, so this is the mode that is more important than partial load.
in addition to what Paul wrote regarding that cold start issue i would check the temp switch which controls the cold start valve. leak air is another possible cause of the problem.
fritz
12-29-2012, 08:52 PM
#4
Rennlist Member
you`ll need the valve to check system pressure additional to cold and warm control pressure. more important is a handpump for checking the full throttle enrichment, activated by boost pressure.
btw, the oe wur is adjustable. the steel membrane is under pressure of a double spring. the inner spring is activated by a diaphragm under boost pressure. the basis of that inner spring is adjustable due to a fine thread srew.
the ft enrichment affects the afr above 0,3 bar boost, so this is the mode that is more important than partial load.
in addition to what Paul wrote regarding that cold start issue i would check the temp switch which controls the cold start valve. leak air is another possible cause of the problem.
fritz
btw, the oe wur is adjustable. the steel membrane is under pressure of a double spring. the inner spring is activated by a diaphragm under boost pressure. the basis of that inner spring is adjustable due to a fine thread srew.
the ft enrichment affects the afr above 0,3 bar boost, so this is the mode that is more important than partial load.
in addition to what Paul wrote regarding that cold start issue i would check the temp switch which controls the cold start valve. leak air is another possible cause of the problem.
fritz
Th O.E. wur is not adjustable for cold control pressure, only for boost enrichment control pressure, which is what Brandon will need if the cold control pressure is out of spec.
12-30-2012, 12:34 AM
#5
Burning Brakes
Thread Starter
Is there a way to pressurize the intake tract on these cars? Years ago when my Quattro had a CIS turbo motor (I later swapped in a better Motronic controlled motor) I had a fitting that plugged into the hose right after the fuel distributor and I would hook up a compressor regulated to about 10-15 psi - and finding any air leaks was VERY easy, whether it was a main hose or a mall line....
One thing I always said about that motor after I yanked it was that anybody buying a car with that motor should, first thing, replace all the little braided vacuum lines. I guess I should do that with this car as its CIS...they hate vac/boost leaks. Then again this motor doesn't have quite the spaghetti mess as that motor...but still....
The thing about winter...you just think about all the stuff you _should_ do - the list gets longer and longer - whereas in the nicer months you just drive....
Brandon
'91 911 Turbo
'01 Audi S4
One thing I always said about that motor after I yanked it was that anybody buying a car with that motor should, first thing, replace all the little braided vacuum lines. I guess I should do that with this car as its CIS...they hate vac/boost leaks. Then again this motor doesn't have quite the spaghetti mess as that motor...but still....
The thing about winter...you just think about all the stuff you _should_ do - the list gets longer and longer - whereas in the nicer months you just drive....
Brandon
'91 911 Turbo
'01 Audi S4
12-30-2012, 09:56 AM
#6
Rennlist Member
When I was troubleshooting a boost leak two years ago, I tried to pressuring the intake tract on my car to no avail. I also had a wrench smoke it, which revealed nothing. In the end the crack in the injector block grew so big that I could hear it whistle under boost.
For now you should just remove the intercooler and check over everything, making sure all lines and hoses are tight and seated. Something else that you can do is replace all the worm clamps on the couplers with t-clamps. Have a look here: http://www.summitracing.com/search?k...20clamps&dds=1
You could replace the boost signal line (it tees off to the decel valve) too. Otherwise, more serious surgery will be required as in removing the intake manifold and replacing the injector blocks.
I hear you about winter projects. My car has had the garage all to itself forever (I've trained my wife to scrape her windshield every day). The driving season is so short in places where it snows that you pretty much have to pull the car apart in the winter.
For now you should just remove the intercooler and check over everything, making sure all lines and hoses are tight and seated. Something else that you can do is replace all the worm clamps on the couplers with t-clamps. Have a look here: http://www.summitracing.com/search?k...20clamps&dds=1
You could replace the boost signal line (it tees off to the decel valve) too. Otherwise, more serious surgery will be required as in removing the intake manifold and replacing the injector blocks.
I hear you about winter projects. My car has had the garage all to itself forever (I've trained my wife to scrape her windshield every day). The driving season is so short in places where it snows that you pretty much have to pull the car apart in the winter.
12-30-2012, 11:32 AM
#7
Burning Brakes
Thread Starter
That's kinda funny - my wife parks outside and both my cars get the garage. But actually I'm not a jerk - we have an old house with what I call a 1.9-car garage - so her car would just barely fit - and with young kids flinging doors open - they would hit any other car in there or the brick walls. So outside her car stays. I do try to clear it off for her on big snow days - especially if I'm hoping to get some nooky soon LOL...
Speaking of boost leaks etc. How much vacuum do these typically pull at idle?
My plan is to get a vacuum/boost gauge installed - not sure where yet - may just keep it in the glove compartment and pull it out occasionally to check/monitor. My gauges have white(silver?) faces so getting a matching clock boost gauge may be tough - plus I think you lose warning lights which I don't want to do.
Also need to mount up the AFR gauge I bought - just did a cheapy AEM - should be fine for my intended use - basically just to get the WUR adjusted once I get it - and increase boost to around .9-ish.... Same with AFR - don't need it permanently mounted - just in place so I can check it every once in a while or if something doesn't feel right. Would love to mount them in the ashtray but I don't think they'll fit....
I need to get off my butt...
Brandon
'91 911 Turbo
'01 Audi S4
Speaking of boost leaks etc. How much vacuum do these typically pull at idle?
My plan is to get a vacuum/boost gauge installed - not sure where yet - may just keep it in the glove compartment and pull it out occasionally to check/monitor. My gauges have white(silver?) faces so getting a matching clock boost gauge may be tough - plus I think you lose warning lights which I don't want to do.
Also need to mount up the AFR gauge I bought - just did a cheapy AEM - should be fine for my intended use - basically just to get the WUR adjusted once I get it - and increase boost to around .9-ish.... Same with AFR - don't need it permanently mounted - just in place so I can check it every once in a while or if something doesn't feel right. Would love to mount them in the ashtray but I don't think they'll fit....
I need to get off my butt...
Brandon
'91 911 Turbo
'01 Audi S4
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12-30-2012, 01:11 PM
#8
Rennlist Member
My plan is to get a vacuum/boost gauge installed - not sure where yet - may just keep it in the glove compartment and pull it out occasionally to check/monitor. My gauges have white(silver?) faces so getting a matching clock boost gauge may be tough - plus I think you lose warning lights which I don't want to do.
Also need to mount up the AFR gauge I bought - just did a cheapy AEM - should be fine for my intended use - basically just to get the WUR adjusted once I get it - and increase boost to around .9-ish.... Same with AFR - don't need it permanently mounted - just in place so I can check it every once in a while or if something doesn't feel right. Would love to mount them in the ashtray but I don't think they'll fit....
Also need to mount up the AFR gauge I bought - just did a cheapy AEM - should be fine for my intended use - basically just to get the WUR adjusted once I get it - and increase boost to around .9-ish.... Same with AFR - don't need it permanently mounted - just in place so I can check it every once in a while or if something doesn't feel right. Would love to mount them in the ashtray but I don't think they'll fit....
Attached is where I put my gauge, in the center console where the cubby usually is:
12-30-2012, 06:34 PM
#9
Burning Brakes
Thread Starter
ha! definitely not implying _you_ are a jerk - but I'm pretty sure you knew that.
That is a good place for a gauge - that cubby is not all that necessary.
Well I was able to sneak in a small drive today - after tip-toeing out of the snow/ice covered alley then onto the main roads which are clear. Snow coming agin tomorrow so at least I got that one little drive to tide me over....I'll take what I can get.
Brandon
'91 911 Turbo
'01 Audi S4
That is a good place for a gauge - that cubby is not all that necessary.
Well I was able to sneak in a small drive today - after tip-toeing out of the snow/ice covered alley then onto the main roads which are clear. Snow coming agin tomorrow so at least I got that one little drive to tide me over....I'll take what I can get.
Brandon
'91 911 Turbo
'01 Audi S4
