Rough idle and lean AFR!
Ok so I have an 04 EVO 8 fq330.recently the car has been struggling to idle.hanging and choking often dying out. On start up the car will rev to 2000rpm for about a min then idle down and begin stuttering as if only on 3 or less cylinders. Seems to be fouling he plugs. I've put new plugs in. I have also changed( from my mate evo 8) the coil packs. Idle control valve.maf. cam sensor! Dump valve. Checked for leaks.taken of and 're sealed the inlet manifold.the coil control unit on the bulk head. The fuel pump. Nothing seems help. The car has steel rods, 85.5 weisco pistons. Been port and polished. Bosworth head gasket. 9 exhaust manifold.hks intake and hard pipes. Forge actuator and running a greedy profec 2 boost controller (which I alsomcant work) can anyone help?
MAF still sits on a shelf in my garage and works 100% fine as it always did, hell I have even used it to help troubleshoot a locals car that was having MAF related cels. Plugged it in and car fired without cutting out as it did with their MAF, asked them if they’ve ever cleaned it, it was filthy, owner stated they have in the past with carb cleaner. Hmmmm?!?!?
Best I can say is don’t use the straw on the side of the can and concentrate the flow at the thin wire leads off the resistor inside the housing that may cause breakage of the wire other than that you’ll never damage one, its absolutely done more good than harm with all the crap I’ve cleaned out of mine over the years.
But no MAF no more and wasn’t OPs issue anyway, maybe Fab Five Freddy can add this to his line of questioning on “what’s wrong with my Evo today” posts from now on. Along with “its you’re fuel pressure” which it never is now we have “Do you use CRC MAF cleaner” it’s not to be used for Evos mafs you prob blew you’re engine hahaha!! I’m just happy I found the ignore button!!
not that anyone is still here but maybe for future refernce I am going to post my solution,
it was a combination of things...
1) terrible tune
2) a bad reading AFR this is very rare especially with AEM stuff but mine sadly is no longer reading correctly
Anyways I got my car Re tuned at RRT motorsports by Raif and he did a really good job of showing me the issues and making the car run perfect again, ended up being better than expected, hope this helps someone in the future!
it was a combination of things...
1) terrible tune
2) a bad reading AFR this is very rare especially with AEM stuff but mine sadly is no longer reading correctly
Anyways I got my car Re tuned at RRT motorsports by Raif and he did a really good job of showing me the issues and making the car run perfect again, ended up being better than expected, hope this helps someone in the future!
So your fuel pressure was wrong and you got a band aid fix by retuning it.
That happens all the time.
It'll go wrong again and you'll need to pay again to fix it again.
With another retune.
If you measured the fuel pressure.....you'd know.
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