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My car has been plagued with this issue for a while now. Dealer I bought it from looked at it but couldn't find what is wrong with it. They want to wait for the engine light to come on before diagnosing I got a little video that shows what's going on. This is as bad is at get's usually it doesn't hunt that long, but it is what happens every time the car sits for a day or two. Ones it settles at about 1100RPM it will sit there for a minute or two until it warms up, drop down to 750RPM and run like a charm after that. Pulls strong, and starts without any issues while at temperature. If you experienced this before or have seen it somewhere i could use some ideas as to what it might be. Dealer apparently checked for vacuum leaks and compression, it was all good. I did have a topic open a while back about it but without the actual video.
Sounds like it's running on 4 cylinders. I would connect Durametric and check the misfire counters to see if a particular cylinder is misfiring. In the video, did you hold the gas pedal or the engine was able to hold idle by itself?
I wasn't touching anything, it was hunting by itself. It is like i said, probably the worst i have seen. Will hook up a durametric in a couple of hours and see what's there. Thanks fro the niput, always helpful!
Also note the coolant temp and air intake temp to see if they correspond to the ambient correctly. MAF should read 15kg/hr or a little higher @1k rpm. What are the cam deviation angles, FRA, and RKAT values?
Thanks Ahsai, i will make sure i monitor those values. Yes, only when engine is cold. If i go for a ride, shut the car off, and start it up while still warm, no issues, sits at about 750RPM and no hunting or rough idle at all. It doesn't even have to be at full running temperature.
Also search for "Cold start stumble" for similar cases. One particular case was two leaky fuel injectors (not easy to diagnose...pretty much only after eliminated everything else).
Assuming that's a cold engine when you first start it in the video, I'm wondering why your Oil Pressure doesn't shoot up to 5... Just another observation...
Ok i did a quick check on the durametric software, no misfires. I tryed to capture some data as Ashai instructed. Unfortunately the software crapped out the first time i started the car when it was completely cold. It ran for about 30 seconds, i reset the software and tryed it again. There was no irratic running the second time around and this is the numbers i got. Let me know what you see. Thanks.
Mine always shoots up to 5 when cold on both m1 0w40 and Castrol 5w40.
LN spin on could have something to do with it but wonder what others with the spin on using same oil are getting...
I was kidding. Both 0w40 and 5w40, the oil pressure should still shoot up to 5 when cold. I also don't know the effect of the LN spin on filter but my guess is it should not have any effect because the OE filter normally will also filter 100% and only at the startup instant if the spring is weak some oil will bypass it.
I've definitely never experienced anything like that on my 40th. What muffler do you have? Likewise on mine (with muffler bypass), on a cold startup after sitting a few days, it cranks right up but has a bit of that lope when the secondary air pump is still running. It's nowhere near the severity of yours though; the tach is pretty stable and it just sounds a bit lopey.
Like you, I hooked up a durametric, found no misfires or anything suspicious, and just made an effort to drive it more. It also is a bit better when the car has been on the battery tender.
All the numbers look good. I just re-read your old thread now. A lot items have been checked already. One suggestion re the purge valve may be worth trying since it's easy. You just disconnect the fuel vapor line at the quick disconnect then seal both ends before you start your cold engine.
Another test is to verify the fuel pressure at start up, which is more involving.
Leaky fuel injectors is a strong possibility too but it's difficult to diagnose. I suppose a crude test can be like this. Park the car and leave the engine running, then remove the fuel pump fuse (c4) and let the engine die. In this way, the fuel pressure should be all bled out. Replace the fuse the next time you start the car cold. Leave the key at the last position before crank to leave enough time for the fuel pump to prime before cranking.
Doesn't look to promising, he lives not too far from me, and the dealer he speaks about is my local dealer that i took my car to. Too many things check out good, yet the car keeps running bad at every startup.
09-23-2014, 05:43 PM
Rough Startups
I got a little video that shows what's going on. This is as bad is at get's usually it doesn't hunt that long, but it is what happens every time the car sits for a day or two. Ones it settles at about 1100RPM it will sit there for a minute or two until it warms up, drop down to 750RPM and run like a charm after that. Pulls strong, and starts without any issues while at temperature. If you experienced this before or have seen it somewhere i could use some ideas as to what it might be. Dealer apparently checked for vacuum leaks and compression, it was all good. I did have a topic open a while back about it but without the actual video.
