[RESOLVED] misfire help P0300 - ISC & coil results

[bboyalan]

Hey guys! I've been trying to fix this w/ my dad since Friday night, but I must resort to asking for help now as it is simply too time consuming w/ college and all...

Long story somewhat shorter [so I can explain the current situation]:
-A'PEXi dp + high flow cat installed friday noontime [nice, powerful drive home]
-installed boost/vac gauge on that friday afternoon [easy source taps]
-tried drilling through passenger footwell w/o looking
-ended up going through steering wheel boot [success!]
-key in ignition = no go for instrument cluster
-car would crank, but not start
-ends up I drilled through the wires behind and beneath the battery...
-reconnected and wrapped up wires
-car cranks, starts, but has terribly low, bogging idle [200RPM near death]
-smells like unburnt gas [not enough air in mixture for combustion?]
-checked plugs and wires
-replaced 1-month old NGK G-power platinums [toasted] w/ *new* NGK iridiums
-did the throttle SAS + BISS adjustment properly to help idle @ 400-500 RPM
-test drove and had POOR acceleration + threw p0300 code for random misfire
-erased code & grounded the brown plug for ignition timing adjustment
-boost and vac leak check
-test drove again w/ the same poor acceleration, P0300 code, but <400RPM now

SO NOW [and I apologize for the brief summary] I'm here w/ some diagnostics/results and hoping to get some good direction and recommendations. We pulled the plugs out after the code was thrown to see if any weren't firing and they all checked out okay. I also tested the ISC [Idle Speed Control] and came up with 41 Ohms on each [supposed to be 28-33]. In addition, I tested both the primary and secondaries of my coil pack. The secondary checks out within proper range, BUT the primaries were showing 11.2 for each [should be 0.70 - 0.86]. My NGK wires are 1-month old and have good resistance in them.

What should I be testing for or replacing next? I have such a terrible headache from thinking about this on the constant and I've devoted practically ALL of my study time towards searching the forum + trying out new things. If there is any other information that's needed, then I'll try my best to provide them. Any help is appreciated!

ps: this thread seems to have a similar problem minus the first half of b.s. I had went through.

 

[voodoogsx]

I was thinking about this yesterday but I don't see how the two are related. Could it be a coincidence? Or better yet, if it is related to the hydraulic system from the clutch then how can we check it? How do we verify that the system is putting out the correct electrical signal?

Tomas

Unless you crimped some wires or something while bolting the trans back on, I highly doubt this would be were the issue would originate from....think about it. The only connection you have is to the clucth release button under the dash....thats the only signal you'd get on whether or not the clutch was up or down. It only matters when you're starting unless you've already unplugged it. As far as that goes, I've yet to run into any issues after unplugging that switch on my car. Don't fixate on what you changed, trace your steps back...what could you have done that might have caused this while you were putting things back together....

 

[Artago]

Unless you crimped some wires or something while bolting the trans back on, I highly doubt this would be were the issue would originate from....think about it. The only connection you have is to the clucth release button under the dash....thats the only signal you'd get on whether or not the clutch was up or down. It only matters when you're starting unless you've already unplugged it. As far as that goes, I've yet to run into any issues after unplugging that switch on my car. Don't fixate on what you changed, trace your steps back...what could you have done that might have caused this while you were putting things back together....

Yeah I agree with that, but I don't know enough about the clutch system to be able to say for sure.

Regarding tracing my steps back. Well that's going to be tough because the problem arose when it came out of the shop after they put in the motor. So it's could be one of a million things that they touched and I just don't know about.

Tomas.

 

[voodoogsx]

Yeah I agree with that, but I don't know enough about the clutch system to be able to say for sure.

Regarding tracing my steps back. Well that's going to be tough because the problem arose when it came out of the shop after they put in the motor. So it's could be one of a million things that they touched and I just don't know about.

Tomas.

Yeah, I see your point....that does make it a bit more difficult ....regardless, I would seriously rule out the clutch system. It's a hydraulic system with no electronic components. I've got a 95 same as you. I've replaced the master and slave cyl plus added the ss line in mine. The only thing is the switch above the clutch pedal if you still start the car with the clutch in....I'll double check in the manual though shortly...

edit: actually, found this on the site....very useful
for the clutch in particular: Clutch and Clutch Release
Clutch Control
for the whole car: 2G Turbo

 

[PieEyedPiper]

Yeah, I see your point....that does make it a bit more difficult ....regardless, I would seriously rule out the clutch system. It's a hydraulic system with no electronic components. I've got a 95 same as you. I've replaced the master and slave cyl plus added the ss line in mine. The only thing is the switch above the clutch pedal if you still start the car with the clutch in....I'll double check in the manual though shortly...

edit: actually, found this on the site....very useful
for the clutch in particular: Clutch and Clutch Release
Clutch Control
for the whole car: 2G Turbo

Handy links, but it may be short sighted to rule out the clutch with all this anecdotal evidence.
Of course there are no electrical components to the hydraulic system. But when so many of us have had this issue only after clutch modification, even some of us with similar equipment or driveability issues, like Tom and I, we can't rule out that yet. For all we know the install was done incorrectly and something isn't positioned right causing an imbalance that messes with the crank position sensor's readings.
All of the electrical components rely in part on corresponding mechanical systems. If the mechanical systems are compromised then how can we expect our electrical components such as sensors or even the ECU to respond appropriately.

Glad to have you on board for the debate, but I'm not going to dismiss certain things simply because they have no electrical components.

 

[Artago]

Handy links, but it may be short sighted to rule out the clutch with all this anecdotal evidence.
Of course there are no electrical components to the hydraulic system. But when so many of us have had this issue only after clutch modification, even some of us with similar equipment or driveability issues, like Tom and I, we can't rule out that yet. For all we know the install was done incorrectly and something isn't positioned right causing an imbalance that messes with the crank position sensor's readings.

Glad to have you on board for the debate, but I'm not going to dismiss certain things simply because they have no electrical components.

Yeah like a badly installed clutch causing vibrations. My car vibrates from the engine under decel. Very noticeable. So it could be throwing off the CPS or CAS. The sensors themselves could be fine but they could be affected by something mechanical. Just my $0.02.

At this point I'm not ruling anything out. Even gremlins living under the hood are a possibility.

Tom

 

[voodoogsx]

Yeah like a badly installed clutch causing vibrations. My car vibrates from the engine under decel. Very noticeable. So it could be throwing off the CPS or CAS. The sensors themselves could be fine but they could be affected by something mechanical. Just my $0.02.

At this point I'm not ruling anything out. Even gremlins living under the hood are a possibility.

Tom

I understand your position, I was more of pointing out the clutch lines and the plate have no direct sensor connection. I do see your point with the cam and cas sensors and had considered it. I'm not convinced this would be the issue....but as you have said, it may be wise to not rule it out.

I surprised with the decel vibration and that you don't get it the whole time....thats odd.
I've seen a similar issue with an automatic, though I don't know what the resolution was or if it would solve the issue with a manual

Anyway, I did some searches and found some interesting postings in them "clutch install" was the search term.
This is with a 1g, but thought it might be of some use...
http://www.dsmtuners.com/forums/pro...-electrical-problem-after-clutch-install.html

Just a thought on the above, could be that the ground wire on the starter could have come loose?

some interesting info with some other folks with the spec clutches.
http://www.dsmtuners.com/forums/420a-drivetrain-tech/282695-vibrating-car-after-clutch-install.html

I had a gremlin under my dash....you should have seen what he did to the wiring...

 

[bboyalan]

UPDATE:

SO, after a long, long day the car IS running w/o the P0300 code!! I first checked the wiring again and discovered that there was more damage deep within the lining. It helped to fix them [blue w/ white stripe, red w/ blue stripe, & black], but not enough... SOOO I went ahead and swapped the ECUs and TA-DA! The car was running pretty damn good & normal EXCEPT for 2 things... FIRST, it was having a jumpy idle and threw a P0130 code at me [front 02 sensor]. I fixed this by trying to fix up the damaged wiring that I had a glimpse of previously [fat green one w/ the special silver fibers]. That code is gone now, BUT there's only ONE slight small annoyance. The car doesn't have as much great top end now. It reaches 11psi [BCS mod] but during 3rd&4th gears it will start to bog/shake and fall off the rpm. It can't really go passed 4-4.5k effectively. IDK how to explain it exactly, but the top-end and acceleration isn't back to normal. I'm just glad that I can drive around now normally [shifting @ 3-3.5k]. Took her on the freeway w/ my best friend and went around S.D. Well there's the update!

 

[PieEyedPiper]

Good job, bboyalan.
Glad you we able to repair the other damaged wires.

I was thinking though, what year is the ECU you used to swap? If it is not a 95/96 it may be responsible for your car acting up at around 4.5k like you mentioned. Other, later ECUs, used a different cylinder firing order. That may not be the case here, but ust some food for thought.

 

[Artago]

Good job, bboyalan.
Glad you we able to repair the other damaged wires.

I was thinking though, what year is the ECU you used to swap? If it is not a 95/96 it may be responsible for your car acting up at around 4.5k like you mentioned. Other, later ECUs, used a different cylinder firing order. That may not be the case here, but ust some food for thought.

I have a 97 ECU I'm going to swap in tomorrow. I was told you need to swap plug wires 1-4 and 2-3. Hopefully it will fix me up like it did bboyalan.

If the 97 ECU doesn't work out then I found some reman units at Auto Parts Fast at RockAuto here:
1995 MITSUBISHI ECLIPSE GSX Engine Control Module (Computer)

Does anyone know of another place (other than the classifieds) to get EPROM ECUs?

Tom

 

[bboyalan]

Thanks heh. The FUNNY thing is that I would have NEVER guessed there were more wiring damages. I only knew because the wire I was working on dislocated itself and totally came off [me: WTF?! =O]. OH!! And another hilarious thing was that it turns out my stock ECU was an EPROM . It was surprising on my part because, as far as I've read on it, they're sought after for DSMLINK right? But yeah, to answer your question the ECU that I swapped in came from a 95 non-eprom turbo dsm [thanks Eric!!]. I knew the ECU fixed everything just from startup alone; my idle skyrocketed to 2000 rpms because of the BISS adjustment and had to be screwed in from beforehand.

I've already tried grounding the brown timing adjustment thing. My only other guess for the odd 4.5K+ acceleration is that my boost tap is throwing sh*t off perhaps? I tapped right inbetween the intake manifold and the solenoid prior to the FPR.

Also, I forgot to mention that my idle sits at 1k. it will occasionally, however, bob up and down between that and 1.1k. Whatever is throwing this reading off my also be contributing to the weird acceleration. Any ideas?

Good luck to everyone else this weekend!

 

[Spades]

My code appeared when I had a new engine put in. Along with the engine came a new clutch. PieEyedPiper has pointed out (on another thread) that a lot of people experiencing this code have had a clutch job.

Wow that is a strange coincidence, I too got the P1400 code along with P0303 code after installing a new engine and new SBR clutch. I cleared the code and thought nothing of it since it was a new engine and figured maybe the computer was just "adjusting" itself. The code appeared twice and thats when I knew something was up. I removed and cleaned the contacts of the MDP and that seemed to fix it, its been good for about a month now

 

[turbosax2]

bboyalan:

As far as I know the ecu you have is from a 95 or 96, but I could be wrong. Have you done a boost leak test recently? Boost leaks can always mess with our cars. This is the very first thing I would check if I were you. Make sure it holds good to around 20 psi.

I guess you could try swapping the injector connectors (swap connector 1 with 2 and 3 with 4). This would have to be done if a 97-99 ecu was being used. This is referred to as "cas inversion" and is usually done when people with a non-95 cas use a 95 ecu. Your situation could be the opposite way.
DSMLink - FAQ

I think the "silver fibers" on the fat green wire is shielding for the o2 sensor wires. There is actually a normal insulated wire inside, then a layer of the silver fibers (shielding), then the green casing to contain it all. The lack of shielding in spots could be why you threw the o2 sensor code.

 

[super97gst]

well, i got the old alternator off this afternoon and it is obviously worn out. it doesnt spin freehanding it anything like the new one. it got dark on me though and i didnt have time to get the new one on. im gonna finish it up tomorrow. im glad you at least partially straightened yours out bboyalan. thats most likely the same thing thats wrong with mine. since ours have been doing the same thing this whole time.

anybody know where i can come up with a late model non-eprom ecu for what little cash i have left

i have no intentions of running dsmlink on mine so i dont need an eprom. and as long as i run a 97-up ecu i dont have to change anything around on the install.

 

[Artago]

Hey everyone. I need some help ASAP. I'm in the MIDDLE of a ECU swap and I'm having 1 problem.

First off. My car is a 95 TSi with EPROM ECU. I'm swapping in a 97 none EPROM ECU.

I swapped the spark plug wires like I was told to. Swapped plug 1-4 and 2-3. However the car wont start. It starts cranking and after a few cranks I heard a "thud" and then I stop cranking.

Any and all help with this would be appreciated. Sun goes down soon and if I can't figure it out then I'm going to swap in my original ECU back. Please help.

Tom

 

[Artago]

Hey everyone. I need some help ASAP. I'm in the MIDDLE of a ECU swap and I'm having 1 problem.

First off. My car is a 95 TSi with EPROM ECU. I'm swapping in a 97 none EPROM ECU.

I swapped the spark plug wires like I was told to. Swapped plug 1-4 and 2-3. However the car wont start. It starts cranking and after a few cranks I heard a "thud" and then I stop cranking.

Any and all help with this would be appreciated. Sun goes down soon and if I can't figure it out then I'm going to swap in my original ECU back. Please help.

Tom

Ok nevermind. I got it. I was swapping the wrong ignition wires. I swapped 1-2 and 3-4. I changed it around and it fired up great.

Sorry for the false alarm. Now I'll run on the 97 ECU for a week and see if the P0300 comes back.

I also, I read on another thread that disconnecting the TPS will stop the car from checking for misfire. I don't really think this is a solution but some food for though.

I'll post an update in a week or when the P0300 code comes back. Whichever comes first.

Tom

 

[Artago]

anybody know where i can come up with a late model non-eprom ecu for what little cash i have left

I can sell you the one I just swapped in after I'm done with it. But you'd have to wait a couple of weeks while I get a reman EPROM unit and then get it DSMlinked. If you are willing to wait that long then it should be no problem.

Tom

 

[super97gst]

I can sell you the one I just swapped in after I'm done with it. But you'd have to wait a couple of weeks while I get a reman EPROM unit and then get it DSMlinked. If you are willing to wait that long then it should be no problem.

Tom

that'll be fine tom. just pm me when you want to do something on it.

 

[bboyalan]

super97gst: Thanks & good luck on the alternator change finish! It's so strange how our cars have super similar symptoms huh? It's a good thing we're all headed towards the same/similar direction.

Tom: Glad to hear everything is working out. Keep us/me updated on how it turns out.

turbosax2 & anyone else: For my oddly enough situation, I can't really fix the damaged portion for the o2 sensor's wiring. The reason being, I can't pull enough wire free to work with from the the side going into the firewall grommet. MY QUESTION is.... IF I cut it apart, extend the wires, bypass the damage/grommet, and reconnect somewhere after, will it work? I'm pretty sure I can do it properly, but I'm NOT certain how important that "shielding" is. Would I be able to get away without the shielding on my extension? Please let me know what you guys think on this one so that I can try it out tomorrow.

~AL

 

[PieEyedPiper]

Dive in. Extend the wires, solder them together, wrap it in electrical tape very well, but cleanly. Mission accomplished.

I don't know how much electronics experience you have, but it shouldn't be too difficult.

But really, what are your choices?

a) run with damaged wiring
b) replace the harness (potentially $$$)
c) cleanly extend and reconnect the damaged portions of the wiring

I'd rock option c).

 

[super97gst]

Dive in. Extend the wires, solder them together, wrap it in electrical tape very well, but cleanly. Mission accomplished.

I don't know how much electronics experience you have, but it shouldn't be too difficult.

But really, what are your choices?

a) run with damaged wiring
b) replace the harness (potentially $$$)
c) cleanly extend and reconnect the damaged portions of the wiring

I'd rock option c).

option C)

the shielding wont matter much on your 02 sensor wiring. it isn't like a coax wire where the shielding is actually ground and the signal travels through the shielding in a copper electrode.

if you really want shielding on it they sell different size wire shielding, just like whats on there oem at advance auto parts. it's in the help section, but im sure oreilly's or napa would have it too.

 

[bboyalan]

Thanks for chiming in guys! The main reason I wanted to ask for opinions first is that there's no turning back after I snip the wire to go "Option C"; well, at least not any way to go back soon. Anyway, I'll post back later today. Keep it up!

 

[Artago]

24 Hour Update:

Ok so it's been 24 hours with the new ECU and here's an update.

1. P0300 is gone. (Too early to say for sure but it hasn't returned yet)
2. Accel, Decel, Idle, WOT, Cruise is all smoother. No more misfiring. Car sounds a whole lot better. Runs stronger and cleaner.
3. Some weird idle issues have been resolved, but I still have high idle when warm due to a vac leak.
4. NEW PROBLEM: It threw a new code at me P1105 (Fuel solenoid).

Now here's what I'm thinking. If this code is real then why didn't my old ECU pick it up? Is it possible that because it missed the problem is caused the car to misfire and throw the P0300 code instead?

Or is it possible that this problem is new? Or is it a false positive? I'll check the Solenoid sometime soon and get back to you all.

Tom

 

[bboyalan]

Hey Tom,

I've been having a similar situation w/ the higher idle w/ a leak going on too. I was able to eliminate my p0130 code by extending and reconnecting the front o2 sensor's wires, but I'm still getting some higher idle w/ slight surge [1k-1.1k]. My top end is still affected and sappy too. It's strange because the car was running in tip top shape before all this chaos had originally occurred. The ONLY thing that I did that dealt w/ any lines was tapping for the boost/vac gauge. As I've explained earlier, it's the line from the manifold to the solenoid NOT the solenoid to fpr. Each fitting for the T-split is ziptied so I'm not sure what else could be going on. I'm suspecting the biss screw perhaps because it doesn't have a cover on it or most likely the O-ring. Then again, can that little section really make a big difference?? Just thought I'd share.

In regards to your new code, I had the same thought about my code too. THAT in itself is weird because it IS possible to have multiple codes pop up. Why would only ONE - our beloved misfire p0300 - be the only one to show? Crazy DSMs!!

 

[super97gst]

tom, i assure you that you would know if that little bastard fuel pressure solenoid was going bad. that was the first thing i had to do to my gst when i bought it 6 years ago. the car died at every stop sign and would accelerate for crap. felt like extreme ignition retard.

anyways, i have really bad news. the alternator did nothing, and i mean nothing at all. the car still does the exact same thing, idles at only 100 rpm's. this is really getting old. i'm suppose to be starting a new job, its Goodyear Tire, within a couple of weeks and i need this car goin. oh well, i've got an old truck that i can drive i guess until i get my gst going or buy something else for a work car.

i suppose my next option is the ecu swap. you still wanting to do something on that tom?? or are you keeping the one you have or what?? just pm me and we'll work something out if you want, if not i'm sure i can always find a late model thats still good that someone's throwing away for an eprom.

 

[Artago]

Hey Tom,

I've been having a similar situation w/ the higher idle w/ a leak going on too. I was able to eliminate my p0130 code by extending and reconnecting the front o2 sensor's wires, but I'm still getting some higher idle w/ slight surge [1k-1.1k]. My top end is still affected and sappy too. It's strange because the car was running in tip top shape before all this chaos had originally occurred. The ONLY thing that I did that dealt w/ any lines was tapping for the boost/vac gauge. As I've explained earlier, it's the line from the manifold to the solenoid NOT the solenoid to fpr. Each fitting for the T-split is ziptied so I'm not sure what else could be going on. I'm suspecting the biss screw perhaps because it doesn't have a cover on it or most likely the O-ring. Then again, can that little section really make a big difference?? Just thought I'd share.

In regards to your new code, I had the same thought about my code too. THAT in itself is weird because it IS possible to have multiple codes pop up. Why would only ONE - our beloved misfire p0300 - be the only one to show? Crazy DSMs!!

So I was doing an oil change today because I sea foamed the car 2 days ago. The oil only had about 1000 miles on it but it was BLACK.

While doing the oil change I noticed my Vac lines for FPR and FP solenoid were disconnected. I used those line a few days ago for the sea foaming and I must have forgotten to reconnect them . So I reconnected the 2 lines and cleared the code. Hopefully it wont come back.

Regarding the idle. I KNOW I have a vac leak somewhere under the intake manifold maybe under the Throttle body. But I can't fine it. I also have a small vac leak around the ISC and BISS (mine also has no cover). I'll pick up as BISS and ISC O-ring soon and hopefully that will help.

But the BIGGEST leak is the one under the intake manifold that I can't find. I can't see it but I know it's there because when doing a boost leak test from TB back I can hear it loud and clear and the Throttle body -> back system will only pressure to 2 PSI (barely). I have to find this big leak fast but it's proving to be elusive.

Any thoughts or suggestions?

Tom

PS: No P0300 code yet. (Knock on wood)

EDIT: I have the exact same idle symptoms as you. I think it's just Vac leaks.