[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.

 

[super97gst]

anybody gotten anything done yet?? i got a new CAS and CPS ordered yesterday morning from Extreme PSI. should be here monday, ill get the CAS swapped out sometime monday and post back. if these 2 sensors end up not narrowing our problem i think we need to start looking into the MAS. i haven't tested mine, but i have a feeling it could have something to do with this. but you would think if the MAS goes bad you could unplug it and it wouldn't make much of a difference. i cranked my gst yesterday and unplugged the MAS just to see what it would do and it just died so maybe that has nothing to do with it.

also, i thought it might be worth noting that i replaced my coolant temp. sensor and that made no change as well. the dealership thought that was the problem when all this first started a couple months ago. i called and talked to one of the mechanics at the dealership a couple days ago and told him that did nothing and he said it was most likely the CPS then. then the guy got to talking bout crankwalk, so i quit listening. anyways, ill post back results later.

 

[bboyalan]

Heeey guys,

Sorry for not updating. We've only been able to work on the car during the evening [busy schedules], BUT I'm glad to say everything is ALMOST put back together. The sensors have been swapped, new accessory belts, cleaned up the area, engine mount back on, timing marks okie dokie, checked plugs, and yeahhh. I'm going downstairs to put back the wheel well covers, rim/tire, connect the sensor harnesses and battery then *cross my fingers, hope to die, stick a needle in my eye* start her UPPPPPP.

I'll be back in a few moments to post results.

ps: I've also changed my water temp sensor not too long ago. Removing the cam gear bolt = headache as always [supertight].

 

[Artago]

Thanks for the update.

 

[bboyalan]

UPDATE:

So.... I want to cry right now Startup was fine, idle was fine, clutching in was alright, throttle response was good, but acceleration and timing is still P0300 code came back right around the corner and my heart just sank into a pit. WHAT THE MOTHER EFF?!?! I had such high hopes that THIS would work. So much work and late nights... What else could it be?! MAF? ECU? Why can't I/we just drive our beautiful cars problem-free......

Anyone in Socal want to lend me their maf and ecu? heh.

 

[Artago]

^^ Damn... sorry to hear that.

 

[PieEyedPiper]

Next you should try borrowing a MAF/CAS/TPS and lastly an ECU. Sorry that it wasn't the CPS sensor I had a feeling that when those go bad the car stops altogether (like when the sensor is damaged or destroyed by crankwalk). But it would certainly be plausible that it could have been the culprit.

Don't get discouraged, you're near the end, only a few things to try before the giant sledge hammer at the end of this road.

I've got to figure out why mine has seemingly gone away on its own. I changed my CAS and I got the code a few more times for a few weeks and then nothing... no codes for another few months and then I got one CEL for it. Up until even now, a few months later, there is no trace of it. But I know it lingers in the depths of darkness that is my car's evil psyche.


Maybe go through that wiring again and see if anything else was damaged?

 

[super97gst]

ok, im about sick now. my CAS, CPS and knock sensor are supposed to be in monday and now there most likely not gonna fix the problem. im outta money now, so it figures it wouldn't be those things. i think the MAS might be the next thing we need to go to checking. i'll run a check on mine today. sorry bboyalan, sucks doesnt it.

did your car crank up and idle fine though once you got those sensors on it?? cause my car will barely even idle. im still giving a little hope for the sensors ive got on order.

and also, i dont think its gonna have anything to do with the wiring. i have the same problem with mine and i havent drilled through any wiring. sooo....... i dunno.

 

[bboyalan]

Yeah, I definitely feel you on the money part. I just wanted to post a recap of what's been done to keep other browsers up to date:

__readjusted SAS & BISS
__replaced 1-month-old NGK Platinums w/ NEW NGK Iridiums
__grounded timing adjustment [brown thing]
__boost & vacuum leak check
__NEW higher cranking Duralast battery
__swapped in a 1997 GSX's coilpack
__cleaned PCV valve
__cleaned MAS
__cleaned TB elbow and a little bit of the TB itself
__swapped in a 1993 transistor
__replaced & installed NEW accessory belts
__replaced & installed NEW Duralast CAS & CPS sensors

things tested:
__battery
__coilpack
__spark plugs
__ignition wires
__transistor
__TPS
__ISC
__CPS
__CAS

The car DOES startup and idle wonderfully now. It's just driving that's sappy as hell atm. A member on the boards has offered to lend me a 95 ECU to see if that will solve my problem. IF that doesn't work, I'm going to try changing the MAF. After that, and hopefully there won't be an "after that", I'll be clueless, sad, and insane in the membrane. Replacing the sensors is such an incredible task. I'd most definitely recommend having a buddy help. All those belts... tight areas... and putting it back together w/ timing marks... oh boy! Have fun removing the lower timing belt cover =] Mine ended up in 3 pieces because of ONE bolt that I couldn't find!

PS: I now have an extra 1994 Eclipse non-turbo TPS and a 1999 Eclipse turbo ISC if anyone's interested. I'm going to assume my coilpack is still okay since the testing results were similar; I just swapped it to see if it would make a difference.

 

[turbosax2]

The ecu is on its way! I hope that fixes your problem

 

[PieEyedPiper]

ok, im about sick now. my CAS, CPS and knock sensor are supposed to be in monday and now there most likely not gonna fix the problem. im outta money now, so it figures it wouldn't be those things. i think the MAS might be the next thing we need to go to checking. i'll run a check on mine today. sorry bboyalan, sucks doesnt it.

did your car crank up and idle fine though once you got those sensors on it?? cause my car will barely even idle. im still giving a little hope for the sensors ive got on order.

and also, i dont think its gonna have anything to do with the wiring. i have the same problem with mine and i havent drilled through any wiring. sooo....... i dunno.

Whoa whoa whoa.
Your problem is entirely separate from his. Yes you're trying to solve a similar issue but just because a new sensor didn't fix it for bboy doesn't mean it can't help you.

You have to go through all the same steps as we have ( and sounds like you are ) to find what does and doesn't work for you.

Just no sense in getting all busted up because your parts may not fix it. The parts you have coming? They've always been at the same status. They might fix it.

That hasn't changed.

You might consider making a thread of your own, to log progress, if you haven't already. Fire a link my way and we'll get things started.

Yeah, I definitely feel you on the money part. I just wanted to post a recap of what's been done to keep other browsers up to date:

__readjusted SAS & BISS
__replaced 1-month-old NGK Platinums w/ NEW NGK Iridiums
__grounded timing adjustment [brown thing]
__boost & vacuum leak check
__NEW higher cranking Duralast battery
__swapped in a 1997 GSX's coilpack
__cleaned PCV valve
__cleaned MAS
__cleaned TB elbow and a little bit of the TB itself
__swapped in a 1993 transistor
__replaced & installed NEW accessory belts
__replaced & installed NEW Duralast CAS & CPS sensors

things tested:
__battery
__coilpack
__spark plugs
__ignition wires
__transistor
__TPS
__ISC
__CPS
__CAS

The car DOES startup and idle wonderfully now. It's just driving that's sappy as hell atm. A member on the boards has offered to lend me a 95 ECU to see if that will solve my problem. IF that doesn't work, I'm going to try changing the MAF. After that, and hopefully there won't be an "after that", I'll be clueless, sad, and insane in the membrane. Replacing the sensors is such an incredible task. I'd most definitely recommend having a buddy help. All those belts... tight areas... and putting it back together w/ timing marks... oh boy! Have fun removing the lower timing belt cover =] Mine ended up in 3 pieces because of ONE bolt that I couldn't find!

PS: I now have an extra 1994 Eclipse non-turbo TPS and a 1999 Eclipse turbo ISC if anyone's interested. I'm going to assume my coilpack is still okay since the testing results were similar; I just swapped it to see if it would make a difference.

You need to get rid of those spark plugs already. I'm not going to lie to you and tell you that they're the cause of your issue. But they certainly could be and could easily be exacerbating your symptoms. It's just kind of silly to continue on this search when we're not checking the rocks that are right beneath our feet.

 

[bboyalan]

I went ahead and ordered a set of NGK BPR6ES spark plugs. Kinda sad that DSMparts.com only had the 7's and up.

 

[super97gst]

Whoa whoa whoa.
Your problem is entirely separate from his. Yes you're trying to solve a similar issue but just because a new sensor didn't fix it for bboy doesn't mean it can't help you.

You have to go through all the same steps as we have ( and sounds like you are ) to find what does and doesn't work for you.

Just no sense in getting all busted up because your parts may not fix it. The parts you have coming? They've always been at the same status. They might fix it.

That hasn't changed.

You might consider making a thread of your own, to log progress, if you haven't already. Fire a link my way and we'll get things started.



You need to get rid of those spark plugs already. I'm not going to lie to you and tell you that they're the cause of your issue. But they certainly could be and could easily be exacerbating your symptoms. It's just kind of silly to continue on this search when we're not checking the rocks that are right beneath our feet.

pieeyedpiper, i did start a thread on this. about 5 minutes before bboyalan. noone replied. thanks though.

 

[Artago]

Hey all. A little progress on my part. I managed to find a ECU I can borrow to swap into my car. Another tuner member, funguy, has offered to loan me his spare ECU to test. Hopefully I'll pick it up asap and try swapping the ECU. I'll keep you updated on my progress.

Tom

 

[super97gst]

Hey all. A little progress on my part. I managed to find a ECU I can borrow to swap into my car. Another tuner member, funguy, has offered to loan me his spare ECU to test. Hopefully I'll pick it up asap and try swapping the ECU. I'll keep you updated on my progress.

Tom

i just find it really hard to believe its the ecu causing this po300 code. ive done a lot of work repairing circuit boards and usually when a resistor, or power supply or an interface between networks goes down is doesn't do it intermittently. it just fails. maybe thats completely wrong though.

btw, does anyone know what the 2 wires are for that go into the bottom of the brake fluid reservoir? is there some kind of low brake fluid dummy light in the instrument cluster? i was checking for broken wires yesterday and the connector that holds those wires was in pretty bad shape, one wire was pulled out. just wondering what those wires do exactly.

 

[bboyalan]

Yeah, I agree the ECU swap is questionable, but there are reasons behind why we're trying it out. My main reason is that the ECU picks up all the signals from all of our sensors and, thus, creates output depending on what's going on. If our sensors appear to be good, or in many cases, changed, then there MUST be something going wrong. In my case, for example, a lot has been swapped out for new or better conditioned parts, YET my fuel is still not burning correctly and/or on time. In short, INPUT = should be good & OUTPUT = garbage.

BUT YEAH... in regards to your question for the brake fluid, YES it is used to sense the level of fluid I believe. The light will go on when you're low on fluid, and THAT usually results from low, wornout brake pads.

 

[Artago]

i just find it really hard to believe its the ecu causing this po300 code. ive done a lot of work repairing circuit boards and usually when a resistor, or power supply or an interface between networks goes down is doesn't do it intermittently. it just fails. maybe thats completely wrong though.

btw, does anyone know what the 2 wires are for that go into the bottom of the brake fluid reservoir? is there some kind of low brake fluid dummy light in the instrument cluster? i was checking for broken wires yesterday and the connector that holds those wires was in pretty bad shape, one wire was pulled out. just wondering what those wires do exactly.

Yeah I know it's a long shot but I managed to find a ECU so I might as well try it. I may get lucky.

Tom

 

[PieEyedPiper]

pieeyedpiper, i did start a thread on this. about 5 minutes before bboyalan. noone replied. thanks though.

Odd, I've looked through all my PM's and scoured your post. I didn't see a link to it?

Bring it back to life, and log your own progress. If you link me I'll be all over it, and I'm sure Tom will stop by too.

 

[Artago]

...and I'm sure Tom will stop by too.

You know it.

Little update.

I got a spare ECU now but it's from a 97 so I have to swap plug wires 1-4 and 2-3. Hopefully I'll get around to swapping the ECU out this weekend. I'd do it sooner but it's raining a lot here and I don't feel like work right now.

Also, I got my JM Fab Heat shield for the FP Manifold. It's pretty and very shiny.

Tom

 

[bboyalan]

Oooh, I didn't know there was a necessary change when using the 97 ECU. At least you'll benefit from having no speed limiter - not that we should be going 130+ on the streets. Anyway, it looks like we'll both be trying out the swap this weekend. Mine's coming in on Friday [thanks Eric!] and HOPEFULLY it works because my birthday is on Saturday! Now THAT would be a birthday wish come true

 

[super97gst]

Odd, I've looked through all my PM's and scoured your post. I didn't see a link to it?

Bring it back to life, and log your own progress. If you link me I'll be all over it, and I'm sure Tom will stop by too.

umm... well, i dont know. i never pm'd you though. i didnt state the title of the thread as being a po300 code thread, thats probably why noone replied. i'll find it later and pm the link to you. i've gotta get back to work right now.

i got those three sensors in yesterday as well, the CPS, CAS and knock sensor. i went ahead and installed the CAS since its so easy to do. and of course it did nothing. anyways, i'll post back later tonight.

Blake

 

[Artago]

umm... well, i dont know. i never pm'd you though. i didnt state the title of the thread as being a po300 code thread, thats probably why noone replied. i'll find it later and pm the link to you. i've gotta get back to work right now.

i got those three sensors in yesterday as well, the CPS, CAS and knock sensor. i went ahead and installed the CAS since its so easy to do. and of course it did nothing. anyways, i'll post back later tonight.

Blake

I thought 7-bolt's don't have knock sensors. Or do you have a 6-bolt swap????

Tom

 

[super97gst]

i've still got the 7 bolt. buy yea, its got a knock sensor on it. i cant speak for other year models though. its right underneath the intake manifold on my 97.

i also think it might be worth mentioning, i had to crank my gst yesterday to move it out of the way and the battery was dead. well i put the charger on it and cranked it up. with the battery charger still hooked to the battery on high the car ran a little better. as soon as i unhooked the charger leads the car almost died. probably just because the battery was almost dead from sitting there for so long now. maybe the ignition system wasnt able to get enough juice to operate.

 

[Artago]

i've still got the 7 bolt. buy yea, its got a knock sensor on it. i cant speak for other year models though. its right underneath the intake manifold on my 97.

i also think it might be worth mentioning, i had to crank my gst yesterday to move it out of the way and the battery was dead. well i put the charger on it and cranked it up. with the battery charger still hooked to the battery on high the car ran a little better. as soon as i unhooked the charger leads the car almost died. probably just because the battery was almost dead from sitting there for so long now. maybe the ignition system wasnt able to get enough juice to operate.

Oh that reminds me. I remember reading a thread where a guy claimed that swapping out his alternator fixed his P0300. Something about the old one dying and putting out a unsteady current flow.

Maybe we should look into this.

Does anyone have a spare alternator they can throw in and try? Can anyone get one?

Thanks,

Tom

 

[PieEyedPiper]

Oh that reminds me. I remember reading a thread where a guy claimed that swapping out his alternator fixed his P0300. Something about the old one dying and putting out a unsteady current flow.

Maybe we should look into this.

Does anyone have a spare alternator they can throw in and try? Can anyone get one?

Thanks,

Tom

Bah! I was gonna say that!

I was actually thinking about that very post in a dream or something this morning. Yeah, I know. I'm weird.

I thought 7-bolt's don't have knock sensors. Or do you have a 6-bolt swap????

Tom

You're probably thinking of how only 1g's have the ability to log knock, and that the only option for 2g's really is DSMlink, AEM or something if we want to see the knock count. Turboglenn also has some unique setup to make better use of a knock sensor.

 

[Artago]

Bah! I was gonna say that!
I was actually thinking about that very post in a dream or something this morning. Yeah, I know. I'm weird.

Don't worry. You're not the only one who dreams about problems with his DSM.

Regarding the alternator. Is anyone willing to give it a shot? Any spare alternator's lying around?

Tom