POLL: What injectors do you have and do you experience cold start misfires?
08-25-2006, 12:40 PM
#52
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JD...it might be the plugs imo...havent had any coldstart issues with AWE injectors (Green Giants)..
when using the plugs they supplied...NGK platinums. I switched couple months ago to Bosh Platin F5DP0R.....and the one range colder seems to cause a quick "spike" in rpms at startup (which drops down almost immediately) as well as the "occasional" misfire (like once every 2-3 weeks). I noticed it immediately once the Bosch plugs were swapped in. So.....i'm thinking its the one range colder effect...cuz once warm, she idles like a champ and no misfires whatsover. *shrugs*
Do you only get misfire codes while the engine is cold?
08-25-2006, 02:15 PM
#59
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I'm convinced that the cold start issue has nothing to do with injectors ...
- I never had this issue with my S4 when it was running the green tops (others think it is the greentops)
- AWE swithces to the green giants, then all of a sudden the cold start issue starts again
- I have their new fueling kit with the green giants on the Allroad, car is perfect for 6 months, then multiple misfires start and then very ocassionally the cold start problem
- the following list is what was wrong with my car, all of which I believe was somewhat responsible for either the misfires / cold start problem as some things were fixed first, thought the problem went away, then it came back and fixed a few more things
1) The check valve to the drivers side of the Y-pipe had a crack in it (actually a hole) - apparently from a good audi tech that found the problem, this is a common issue with the 2.7s
2) Coolant sensor was going bad, at first it wasn't throwing codes then finally started throwing codes
3) I posted this 3 weeks ago but I will say it again, the oem washers that fit over the oem injectors fit absolutely snuggly on the oem injectors but do not on the green giants. I think as a result of this, when the fuel rail / injectors are installed, I think people are possibly getting crushed washers that eventually crack. This is exactly what happend to my Allroad, the washer on #4 was cracked. My mechanic started the car and then while the car was running sprayed brake cleaning fluid on top of the location of each injector, while vag was hooked up monitoring misfires, and you could hear a massive sucking sound when he did so ontop of #4 and then the vag showed misfires. You couldn't hear the sucking on #2 or #6 but a few misfires would show up. So he took everything apart and sure enough, the washer on #4 was cracked and then he noted that the OEM washers DO NOT fit snuggly over green giants. What he did was order a set ov new washers and then use teflon tape to first wrap around each injector before he put the new OEM washers on so they would fit as snuggly as they do on the OEM injectors.
I can't say for sure but I think it is 95% likely that the cold start / misfiring issues that occur are not injector related but are a combination of small issues, some of which I have mentioned above.
There are just too many 50 cent parts on this car that can go wrong at 20psi
Hope you find the problem
- AWE swithces to the green giants, then all of a sudden the cold start issue starts again
- I have their new fueling kit with the green giants on the Allroad, car is perfect for 6 months, then multiple misfires start and then very ocassionally the cold start problem
- the following list is what was wrong with my car, all of which I believe was somewhat responsible for either the misfires / cold start problem as some things were fixed first, thought the problem went away, then it came back and fixed a few more things
1) The check valve to the drivers side of the Y-pipe had a crack in it (actually a hole) - apparently from a good audi tech that found the problem, this is a common issue with the 2.7s
2) Coolant sensor was going bad, at first it wasn't throwing codes then finally started throwing codes
3) I posted this 3 weeks ago but I will say it again, the oem washers that fit over the oem injectors fit absolutely snuggly on the oem injectors but do not on the green giants. I think as a result of this, when the fuel rail / injectors are installed, I think people are possibly getting crushed washers that eventually crack. This is exactly what happend to my Allroad, the washer on #4 was cracked. My mechanic started the car and then while the car was running sprayed brake cleaning fluid on top of the location of each injector, while vag was hooked up monitoring misfires, and you could hear a massive sucking sound when he did so ontop of #4 and then the vag showed misfires. You couldn't hear the sucking on #2 or #6 but a few misfires would show up. So he took everything apart and sure enough, the washer on #4 was cracked and then he noted that the OEM washers DO NOT fit snuggly over green giants. What he did was order a set ov new washers and then use teflon tape to first wrap around each injector before he put the new OEM washers on so they would fit as snuggly as they do on the OEM injectors.
I can't say for sure but I think it is 95% likely that the cold start / misfiring issues that occur are not injector related but are a combination of small issues, some of which I have mentioned above.
There are just too many 50 cent parts on this car that can go wrong at 20psi
Hope you find the problem
08-25-2006, 02:38 PM
#60
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I'm not convinced either... Here's my thought.
I had a lemi tweaked MTM stage 1. After a while it started to develop cold start issues. Sounded like it was dieseling and basically going to explode on a cold start. I'd shut it off, promptly re-start it and it would be perfect.
It developed this problem. So I thought it was the Coolant sensor. It helped. I then sold the ECU to another S4 owner. I put in the stock ecu, and the issue went away completely.
The new owner of the box promptly started having the exact same cold start issue that I was having. He went in, re-set the lemi-tweaks, and the cold start issue totally disapeared.
This tells me, there are settings in the ECU that cause a cold start issue, and it's not necessarilly the injectors.
Just my observations.
It developed this problem. So I thought it was the Coolant sensor. It helped. I then sold the ECU to another S4 owner. I put in the stock ecu, and the issue went away completely.
The new owner of the box promptly started having the exact same cold start issue that I was having. He went in, re-set the lemi-tweaks, and the cold start issue totally disapeared.
This tells me, there are settings in the ECU that cause a cold start issue, and it's not necessarilly the injectors.
Just my observations.