got a p304 misfire # 4 . and got a p 313 misfire with low fuel.
as far as the low fuel; are we talking fuel pressure or can these things detect each cyl.? i find the latter hard to believe. ....but hence my question. i would think fuel pressure no? the next is if this is in fact a fuel pressure ,why just # 4 ? can these detect lean condition per each cyl.? all they got is the o2 right? can i check individual injectors? don't see how. swapping to another cyl. seems a wicked pita. any thoughts appreciated.

 

Yes it can detect misfires in individual cylinders. Misfire detection is mainly detected with the crank position sensor. The low fuel literally means low fuel in the tank not the pressure. Misfires with low fuel are not uncommon and this message is there to keep you from wasting time diagnosing it. I would clear the code and see if it continues to misfire with at least a half tank of gas. If it continues, I would check the the fuel trims for lean condidtions. If so, I would look for vacuum leaks, especially at the injector o-rings. If not, check the plugs. If it happens only in two cylinders, I woiuld suspect the coil pack. If only in one cylinder, maybe an injector, but I doubt it. T he injectors are not hard to swap if it comes down to it. You can check the fuel pressure while you have the intercooler off anyway.

Don't forget that one fault does not a problem make. Keep track of the fault codes and time between them, what cylinders and your fuel trims (adaptation values) if you have access to them.

 

thx ; i didn't get any low trims or high trim codes. i've had #4 in past. i'll swap out the plugs first then the injectors . funny this happens after i/c removal. i know i looked thoroughly ; used propane . couldn't find a leak at all . had the collapsing pcv hose and all too all at once . what's the longevity of these boots? these are 3+ yrs. ?

 

some scanners have access to the fuel trims. This can help point you in the right direction. You will not get codes for them unless they are near the adaptation limmits. New boots wouldn't hurt either. how often do you get this code?

 

it just started. but here's the thing... i've got low compression on #4 due to what appeared to be rings. wet test was huge improvement over dry. so i'll swap the plugs. it's not burning any oil but it does have more blow-bye. so it may also be an intermittent lean condition. at the time i did the test it was running like a bag o' crap .now good so maybe if the injector wasn't firing well i'd get a poor seal as compared to the others. so ; when it runs like crap again i'll swap the injectors around to see if the problem moves. sound like a plan ?