Low idle and stalling

[jmatyas]

So this morning I get up to go to work and the second I start my car I immediately notice that it does not sound right, almost like someone installed a heavy cam the night before. I check my tach and I notice I'm only at 350-400rpm, which usually it never goes below 700ish. When I rev the car it runs like normal and everything seems fine...at first. Once I start heading to work I get to a stop light and pull the car out of gear to coast to the light and my car dies, started up just fine but still had the very low idle. Make it to work and pop the hood and I notice a odd rattling sound coming from the timing belt area. Anyone have any ideas what to look for first? Thank you for any input.

Mods list:
Evo 3 16g
PR FMIC
1g crushed bov circulated
AEM boost gauge

 

[XiKeiyaZI]

If you say that you noticed a rattling from the timing belt side then what it makes me immediately want to suggest is to check your timing and make sure that you didn't have some sort of mechanical failure causing your timing belt to slip. Hopefully if something like this did occur then it wasn't enough to kill your valves.. which since you were able to continue driving it's not likely but still a major possibility. Choppy idle, poor power, poor idle, and dying at stops are all symptoms of a cam/the crank being off a single tooth or two. More would ultimately lead to valve-piston impact.

So, go ahead and pull the timing cover and check your mechanical timing. Just ensure that you are still in mechanical time. If you are, try to find the rattling. Figure out what it loose and set that aside in your mind. Afterwards proceed to perform a boost leak test, compression test, check your TPS/BISS/ISC adjustment, and so on.

 

[Abe'sGST]

Definately check your timing, and if you have never replaced your timing belt, it may be time to go ahead and do it. Try not to drive it until you fix it.

 

[Jesse2012]

Just a thought - this happened to me one time and one of the spark plug wires had come loose. Not necessarily your problem, but it made a noise near the timing belt too, so it can't hurt to check

 

[colemoney1]

I'm with these guys, try not to drive it till you check the timing and make sure you haven't jumped, I destroyed my engine this exact same way. It's not worth the risk of driving it, take the bus

 

[Mitsubishiown]

I have a very similar problem any results? I am throwing an o2 code and a transmission selenoid code not sure if that matters.

 

[RayBan GST]

open the cover and check the timing belt , check if all is alligned , if yes move forward to boost leaks, ignition and other stuff. if the belt is not alligned DONT drive the car.

 

[92boostinawd]

had the same problem check your ISC and of course the timing!

 

[Mitsubishiown]

Whats the part number on the ISC?

 

[jmatyas]

Hello all and thank you for your info so far. Sorry it has taken me a few days to get back on here with an update. After taking the timing belt cover off and doing a good inspection we found out the rattle was thankfully not a knock or tap of any kind, yet the harmonic balancer went bad and was tapping the cover.

After replacing the balancer the car is now nice and quiet, but sadly this did not fix the idle issue, I knew in my heart it probably would not but hey, it's good to hope from time to time. The next step I took was a smoke test to see if a vacuum line had a leak or an intercooler pipe had come loose, after a full text no leaks we're found anywhere.

So now I'm stuck with a surging idle after the car gets warm with no CEL codes of any type. Any ideas on what to try first? I checked the tps and other sensors and they all say they are ok. I'm absolutly lost at this point and any help would be much appreciated. Thanks.

 

[filabob1]

Could it be a bad cam positioning sensor?

 

[moronthr33]

A smoke test is ok but what you need to do is a boost leak test to put so pressure in the system. If you don't know the correct way to do this search the fourms.

 

[jmatyas]

Boost leak test has been done already, sorry I didn't mention it. Built my boost leak tester last year, one of the most important tools in my toolbox.

I did notice today that when I start my car it will stay around 500ish rpm, but once I start driving and it warms up it stays between 900-1100 rpm. Don't know if this helps any but I thought I'd throw it out there.

Also another thing to note is that my car has NEVER thrown a CEL code, even after I switched my ECU to an EPROM ECU it still never threw a code. Kind of odd.