Problem:
-car sounds like it has cams- it does not have cams
-only occurs when I am idling, at normal cruise speeds its okay
-huge problem when its at cold start as it cant stay idling correctly, i have to press on the gas at around 3,000 rpms and hold it..
-I did try to look up the problem and came across it having a poped vaccum hose near the dip stick as shown on this thread
https://www.evolutionm.net/forums/ev...s-do-asap.html

but my evo has a clamp on both ends and its fine.

Any other suggestions? or problems it might have?

 

do you have any modifications?
always check:
-plugs
-fuel filter
-vacuum leak
-updated fuel relays

 

Yes full bolt ons with injectors and fuel pump
Can i get these fuel relays at auto parts? if so: name brand? part number? would help.

 

anybody?

help on idle problem issue or reference on where to buy fuel relays?

 

does your intake have a heatshield? test the relays before you buy them, you can switch out the fuel pump relay for the high beam relay and see if the problem still occurs. If thats the problem, you can buy the relays from SSP

 

-what tune
-do you have a heatshield on the intake? the AC fan will make your car idle terrible

dealership or SSP

 

I have a heat shield on the vehicle. I drove it today to RRE in socal so that mike could take a look at it. Cars sputters ridiculous when in boost.i hope iys not something too serious.

 

Sounds like a very poor tune. You should also check for a boost leak and a spark plug failure.

 

oh wow, Im also having this issue. and I barely have 3300 miles on my evo. stock tune

ive replaced the Fuel pump relay with the blue one and i have the same issues even when the engine is hot. I hear some popping noises coming out of the exhaust when it idles like that. i also have the hesistation at high RPM's sometimes, it used to be all the time, but since i changed out the FPR, it does it sometimes. and i also have the cam noises aswell.

i want to take it to the dealer, but i dont want to be carless for weeks. Im wondering if it is spark plug issues or whatevs.

If anyone knows whats up with this, let us know!!!

 

Im having the same exact issue. I know its something simple but cant seem to find it.

 

If your car is idling sporadically at idle and seems okay at cruising speeds then you have one of two issues...

1: A Vac Leak...excessive air being drawn into/out...check for dry-rotted hoses or collapsed lines

2: A Fuel regulation issue...proper regulation prevents unnecessary fuel entering the combustion chamber and causing ignition failure/inadequate fuel allowed into combustion chambers causing detonation and/or higher combustion temperatures on certain cylinders impeding proper function...usually occurring at cylinders further away from the compression fitting on your fuel rail ( as the regulator/fuel pressures fluctuate the difference between pressure is typically lower towards the end of the rail ). When you increase your RPMs the demand for fuel increases rail pressure and temporarily decreases pressure fluctuations.

I'd make sure that your pump in good by performing a fuel pressure test, if you wanted to go further there are ways to check the REGULATED pressure at each cylinder but oftentimes a bad fuel regulator will show its *** in an obvious way. The best way to check your regulator without spending unnecessary funds on tools and equipment is to leave the vehicle at idle when its at operating temperatures and disconnect the vac line that manages the regulator's internal valving. If the car was running fine and you disconnected the regulator it should idle horribly if not shut off...since your car is idling horribly, a change in operation should occur...usually it operates better due to the higher rail pressures when the regulator hangs almost shut.

If all else fails...your ignition could be the issue.

At idle the ECM regulates voltage to control proper spark Ignition/timing/level of spark...under higher loads this voltage is increased to allow for a higher spark to atomize the increased amount of fuel. So

1: check the resistance in ohms...im not sure of Mitsubishis specifications; however, ignition coils typically measure good between .9-1.1 ohms.

2: Once you have measured the resistance you can then check the voltage of each coil as it fires...using a spark tester and its associated tables you can determine the level of spark or you can use a multimeter to more accurately check output voltage levels.

If all else fails...it could be, seen it before, the egr system fails to properly circulate exhaust gases keeping combustion temperatures down at low load and idle...but I highly doubt its that.

Hope this helps man...looking forward to seeing you fixed your problem...

 

I love the idea that the spark plug is somehow responsible for atomizing the fuel.

 

I had the exact same issue when I bought my X...turned out to be a cracked vacuum hose. OP, I know you said you looked it over for the clamps but did you carefully inspect the hose itself?

 

Im a little lost on your response. The fuel injector induces fuel into the combustion chamber upon compression in a fan like pattern, the ECM sends a signal to the ignition coil which fires the spark plug initiating spark and providing combustion, atomizing the fuel....so yeah, the proper spark of a spark plug is directly involved in the atomization of fuel.

 

It was actually a stretched timing chain.. Got it diagnosed at Road Race Engineering. Once we figured out what was wrong they ended up fixing the problem.