Random missfire? no clue why. help?

[2gawdtsi]

Alright, so my cel has been on for awhile, but it was previously just for the IAC(not the problem right now). Today when i scanned for the codes i got P01259(Temp Closed Loop), P0505(IAC), P1105(fuel pressure fault), and P0443(Evap purge control solenoid). I have no clue where these codes came from. I also adjusted my BISS today because i was idling pretty high. On the way home my car totally took a shit on me and popped up a code for Random misfire. I waited an hour and took it out again and it was fine, until it heated up and wala. It came back. I'm lost

 

[untouchablecc]

Well temp closed loop is usually due to coolant temp sensor an if that fails it would make the car run like crap.

 

[2gawdtsi]

wouldn't i throw a code if my Coolant Temp Sensor was going out? and if it is it seems kind of at a random moment. My car was running fine until i adjusted the idle and such today.

 

[ilco187]

how are your spark plug wires,

 

[2gawdtsi]

they have probably seen better days. they are kind of cracked. Is there any way to test them? wouldnt it more likely be the coil or something like that? because all of the wires shouldn't go at once really..? And if only one went it wouldnt come up as random misfire, it would just give the cylinder. right?

 

[ilco187]

maybe they are arcing off somewhere causing a random misfire or if water or moisture gets down into the hole it can cause the boot to become soft and arc or weak spark

 

[bagged420a]

It only tells you the cylinder that misfires if it is constant not random. If your plug wires are cracked then they should be replaced anyways. A good coil with bad wires=bad spark

 

[2gawdtsi]

yeah, my problem is though that it only starts missfiring once the engine gets hot. The engine has gotten alot hotter than it has today and I havent had a problem with the wires. It was barely warmed up when it started today. How likely is it that all the wires would die at the same time? Just my train of thought at least...

 

[ilco187]

my thought would be the CAS cutting all spark then or inproper coil pack ground

also ignition module

 

[2gawdtsi]

How can i test for CAS and the Coil pack ground? I'm not even sure the Coil pack is grounded to tell you the truth...

 

[2gawdtsi]

or should i be starting elsewhere first? It said the temp closed loop set too soon or something like that, i cant remember exactly. I'm truelly worried about the fuel pressure fault though:/ and i dont have a fuel pressure gauge so i cant see what its running at. could that cause the misfire? if the psi was low?

 

[2gawdtsi]

does anyone have any ideas?

 

[ilco187]

"Closed loop" where the computer takes control and aims for what it considers optimal running conditions. Closed loop is general used during cruising where the computer tries to maintain the stoichiometrially ideal air-fuel ratio of 14.7 parts of air to one part of fuel. That theoretically allows for complete combustion of all gasoline and thus cleanest running.

http://www.dsmtuners.com/forums/art.../191516-how-read-codes-code-meanings-ecu.html

you said this code-P01259(Temp Closed Loop)

but i come back on this code-PO125 Closed Loop Temperature Not Reached(m/t)

P1105 Fuel Pressure Solenoid Malfunction (turbo)4g63t
PO505 Idle air/control Motor Malfunction
PO443 EVAP COntrol System Purge Control Valve Circuit Malfunction
PO300 Mulitiple Cyliner Misfire (m/t)

http://www.dsmtuners.com/forums/new...-pulling-random-misfire-code-help-please.html

 

[2gawdtsi]

so what do you think is the best area to start on to fix it? i plan on hooking up another coil pack and wires i have off another eclipse tomorrow when i get time, but that doesnt seem to explain why it only happens when its hot? when i turn it on and its cold it runs fine.

 

[asexton6969]

P0300 - Literally what alot of dealers do, (concerning random misfire) to check wires, coils etc. Get a water bottle and start the car. Spray the wires and coil, Dont soak the crap out of them, just get water on them. If the car misfires and almost dies. Therein lies your problem, it should react immedaitely as you spray the water. There are as well so many other issues that could throw a p0300 code so for now test for that and return with your results.

P0505 Inspect all of the wires and the harness. Report back.

P0125 Possbile casues Thermostat failure, Engine Coolant Temp Sensor Failure, as always wires and terminals as well.

P0443 Check the terminals for corrosion. I remember when I removed mine it was completely corroded. If no corrosion, check the wiring, otherwise replace the solenoid. Should be cheap, I would just pick up a used one off another dsmer.

I will upload a P1105 diagnostic guide, but it basically suggests the solenoid needs replacing. Keep in mind some codes may be caused by another part failing so all the codes you see could technically be caused by one part. Just keep that in mind so you aren't just throwing parts at it. If you need a how to, check some of these parts please let me know.

 

[2gawdtsi]

okay, i just tested the coil and wires with the water, but nothing happened... what else can i try? check engine light hasnt come back on yet, but i also havent driven it so it was hot yet.. Is there anything else i can try?? or should i run it until its misfiring constantly to do these tests?? once it starts misfiring it doesnt stop until you shut the car off and leave it for an hour or so.

 

[2gawdtsi]

where is the coolant temp sensor located? just so i can check and make sure everything is connected and looking good.

EDIT: i just went and drove it all around, pushing it really hard, the light came on. however, i wasnt misfiring.. Is there any way that random misfire can be caused by too low of an idle? cause that is the only difference between today and yesterday.

oh and the CTS works fine, its plugged in and im getting coolant temp reading on my gauges...

 

[asexton6969]

There are two sensors one for the computer and one for the gauge. The sensor for the computer is facing the firewall on the thermostat housing.

As for the P0300 , the possible causes, secondary ignition wires, fuel pump or filter, injector harness connectors, ignition coil circuit, spark plugs, mechanical engine problem, contaminated fuel, PCM power grounds, injectors, restricted exhaust, intake restriction, PCM, evap system, Egr system.

Im using alldatapro and usually i can look up dtc's and it will give me a nice diagnostic path, for these though, its giving me a diagnostic path using Mitsubishi's special tools (im not sure what their engine analyzer software is) basically like how gm has the tech 2 and vw has the VAS units. If I find more I will certainly post it up.

Are you receiving a misfire code for any certain cylinder? It would seem that if your fuel pressure solenoid is malfunction it could cause a lean condition causing that multiple misfire code. Let me know.

 

[2gawdtsi]

alright i will for sure.
Good news on one of the codes though,
i unhooked a solenoid for the evap purge control solenoid or at least i think it is. I've been having problems with it lately and there was tons of gook, earwax looking stuff in between the plugs so hopefully theres my problem on that one. The IAC im pretty sure is because of my bov previously being vented (sisters boyfriend whos a honda mechanic believes its fine either way and told me to keep it off) i finally just decided to recirculate it even though its prob hurting his feelings haha. oh btw no air was getting in through the recirculation tube while it was vented, so i dont believe its random misfiring because of a lean condition. Unless perhaps not enough fuel is getting there which isn't good either. I'm gonna drive it tomorrow and i'll report back how its going. Thanks for all the help guys.

 

[2gawdtsi]

(Problem Solved)!- acted up again tonight and me and my sister's boyfriend put a new coil on, but it wasnt the coil so we hooked up a new igniter and ran like beauty