Knock... What do I do???
#1
Knock... What do I do???
My build thread: https://www.miataturbo.net/forum/t27300/
My 'other issues' threads: https://www.miataturbo.net/forum/t32703/, https://www.miataturbo.net/forum/t33106/
So, I have been having idle issues and found an air leak around one of the injectors. I removed all the injectors to find a cracked o-ring on one of them. I replaced all the o-rings and no leaks at this point, using the brake cleaner technique recommended by Braineak (thanks again).
The idle is great now, I still get CELs but that's not the main problem.. the problem is I hear knock between 4000 and 5000 rpm under load. Stephanie sent me two maps, one rich and one regular map and both still allow some knock. She recommended I change the fuel filter... so I did, still knock is present! She had suggested before that I change the fuel pump if the knock is still there, but I don't want to do that if it just a hunch or a process of elimination. With how messy the fuel filter change was, I would probably have someone do it for me and it would probably cost 5-600 dollars
I really don't think it is the fuel pump, because I don't hear any knock above 5000 rpm or below 4000 rpm and I would guess engine load is higher above 5000 rpm than in exactly that range?!
Any ideas? I have XEDE if anyone has any different maps for a 2002 Miata...
My 'other issues' threads: https://www.miataturbo.net/forum/t32703/, https://www.miataturbo.net/forum/t33106/
So, I have been having idle issues and found an air leak around one of the injectors. I removed all the injectors to find a cracked o-ring on one of them. I replaced all the o-rings and no leaks at this point, using the brake cleaner technique recommended by Braineak (thanks again).
The idle is great now, I still get CELs but that's not the main problem.. the problem is I hear knock between 4000 and 5000 rpm under load. Stephanie sent me two maps, one rich and one regular map and both still allow some knock. She recommended I change the fuel filter... so I did, still knock is present! She had suggested before that I change the fuel pump if the knock is still there, but I don't want to do that if it just a hunch or a process of elimination. With how messy the fuel filter change was, I would probably have someone do it for me and it would probably cost 5-600 dollars
I really don't think it is the fuel pump, because I don't hear any knock above 5000 rpm or below 4000 rpm and I would guess engine load is higher above 5000 rpm than in exactly that range?!
Any ideas? I have XEDE if anyone has any different maps for a 2002 Miata...
#4
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It's impossible to tell without knowing what kind of timing you are running or knowing what your air:fuel ratio's are like. If you want to know if the knock is fuel related, buy a wideband.
#6
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Yeah, do that. Once you know if you are getting enough fuel, you can rule out your fuel pump. FWIW, my fuel pump was weak and my tune was getting leaner and leaner. I replaced it and now everything is rich. Walbro255 is what you want.
#9
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Don't you have a wideband gauge? If not; you should seriously consider installing one. FWIW, I had some fueling issues myself a few months back (in my particular case it was the fuel filter but I only found out about it after I had purchased a 255 Walbro fuel pump and a new O2 sensor) and it was my wideband gauge that saved my motor then. My car was going lean when going into boost and I was able to notice it just by looking at the gauge. I even took my car to a dyno to doublecheck and found that my WB sensor was working properly and my car was indeed going lean when boosting. Just a heads up.
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