My car has been running crappy for the last week. When i push in the clutch to come to a stop it will go back down to idle then the rpms will jump up to almost 2k then it will drop to about 500 and then jump back up to 2k and then drop to the point that it will die. When this started I got a p0300 CEL and so I'm guessing this has something to do with it. If I put the car in neutral while coming to a stop it seems to drop back to idle fine it is more common when I leave it in gear and just push in the clutch and apply the brakes. My mods are, full bolt ons, full cooling mods, meth and 2.6, tuned by Shaun

 

you should probably find out what the CEL means first. I believe that p0300 is multiple cylinder misfire

 

Yes that is the code has anyone experienced the jump in rpms or the motor shutting off??

 

check the plugs then check for vacuum leak

 

Not sure who Shaun is but i would get together with your tuner and have him take a log to see whats going on.

 

first i would check the plugs, then clean your MAF and throttle body. if that doesnt work make sure you have no leaks. could also be the tune but i have a feeling your MAF/ throttle body might be dirty.

 

lol shaun is over on the r e d l i n e forums and he is good tuner

 

if it just started doing this and its not something that happened right after it was tuned i wouldnt suspect anything withthe tune. first thing id do is check the misfire counters, see if one cylinder is much worse than the others. if thats the case, swap the coil from that cyl to another, see if the missfire follows. check your plugs too

next check for vacuum leaks. generally a vacuum leak will also set a p0171, but not always. keep in mind that a vacuum leak is anything between the mass airflow sensor and the cylinder head. the best way is to use an un-lit butane tourch (propare or accetelene works too) and barley turn it on, wave it around any connections, vacuum lines, etc. if the engine smooths out or picks up, you found your leak.

if nothing has turned up, do a compression test, make sure your dont have mechanical damage.

 

good advice

 

Yeah i was tuned back in may and have not had any problems since so i dont think that it is the tune at all. it started happening when i was on my way home from the extreme dimensions open house a couple of weekends back and i have only driven the car a total of 50 miles since that day. I have also noticed that i have been going through meth like crazy since so tomorrow i am going to check that system for leaks. I will also check codes again, plugs, and for vacuum leaks. Idk its wierd because it will just fluctuate the rpms and then get so low that it will die.

 

where is your meth nozzle located? if its after the throttle body and your check valve failed it will be sucking meth all the time, especially at idle. this will tend to flood the motor and cause a misfire.

unhook your meth line and see if there is any vacuum on the hose side of the check valve. also try plugging it and see if the engine smooths out.

 

Ok I will try that, I have the aem meth kit so I believe the check valve is built into the nozzle. I will b checking all of this today and ill have an update later

 

Ok I think I have found part of the problem if not the whole problem, I took my nozzle out and pushed the test button so it starts spraying but once the pump shuts off fluid continues to flow a little bit so when the pump turns back on it takes a second or two for fluid to actual start spraying so the fluid between the pump and nozzle is leaking out the nozzle into the intake. Does anybody have a suggested solution. I'm probably going to order a new nozzle from aem. I'll post a video of the nozzle spraying.