2G P0300 & P0443. Ideas needed.

[spyderdrifter]

So for the past 2 weeks my GST has been bogging down at random moments while on flat, level roads, and while trying to climb certain hills (not all hills), and here and there while decending hills. I just borrowed a regular scanner from a friend this morning and it gave me the P0300 (random/multiple missfire) code, and the P0443 (evap curcuit malfunction) code. I've already read many posts about the evap code on here and have a decent understanding of what's wrong, and how to reconcile the problem, if I choose (I blocked the EGR during the rebuild). The missfire is pretty straight foward too. I want to know if the evap issue can cause the bogging if there's an issue other than the EGR being blocked. Also, can the bogging be more than plugs and injectors? I pulled the plugs out a couple nights ago and they looked better than when I put them in. Could this just be a deceptive appearance on the plugs? Also while driving up this one specific hill, that I have to drive over to get to work, I've been able to compinsate the bogging/ missfire by down shifting and trying to add more of a boost charge to raise the rpms over the point of the missfireing, and then it handles the hill better. What could that mean as far as the bogging only being during a specific rpm range? Thanks in advance

 

[gofer]

This is why your getting the random misfire P0300 CEL.

6-bolt short block swap w/ '94 CAS, 2G 7-bolt cylinder head, T-28 Turbo, Balance shaft eliminator, Topline OEM intake & exhaust valves, New OEM head bolts, Brian Crower valve springs, Ferrea valve seals, SBI valve keepers (valve locks), Crower titanium valve spring retainers, Wiseco .020 8.3:1 pistons & rings, Topline .020 Rod Bearings, Topline .020 Main Bearings, Topline 6-bolt Lower Gasket Kit, Topline 7-bolt Head Gasket Set, Felpro Turbo Mounting Gasket Set, A/C deletion, Hot tanked head and block, Decked head and block, .020 block bore and hone job, .020 crank grind job

If you've got an evap CEL then I'm guessing you pulled the emissions vac lines off the car and pulled the sensors as well? Do you have a WB o2 sensor gauge or a narrowband?

 

[spyderdrifter]

I have a narrowband, but it's not yet hooked up, was the least of concerns though. Are you saying that the P0300 code is because the CAS isn't properly adjusted?

 

[gofer]

Magnus Motorsports:1g in a 2g<--- See page 10 "Troubleshooting" paragraph about the 1g CAS in a 2g.

Here's RRE fix to the problem, quoted directly off their website.

How do I get rid of the Random Misfire studded and check engine light?

RM (Random Misfire)The ECU is flagging a misfire condition because the crank
sensor which originally drove the hyper accurate signal for the 2G ECU has now
been replaced and simulated by the not so accurate 1G CAS. The only remedies
for this symptom once you have it is:

1. Start over again and do it the original RRE way by modding the oil pump case
and keep the crank signal. RRE does not do it this way anymore, so why would
you?

2. Wire in a potentiometer on the barometric sensor wire going to the
ECU,thereby fooling the ECU into thinking you are at very high elevation (low
barometric pressure) so it doesn't check for RM. This sounds simple, but if you
don't tune the engine to compensate for the additional timing, you will end up
turning your piston's to goo which also kills your turbo. (Not a recommended
fix)

3. Cutting the TPS sensor wire. This actually appears to work for some
people,but since TPS is useful for data logging and tuning, its not a good long
term fix. This may also effect engine performance during times when the ECU uses
rapid changes in throttle position.

To be perfectly honest with you, ECMLink might be the only SAFE way of getting rid of the P0300 code. But if thats not in your cars "to do" list you can try the above suggestions from the experts.

 

[spyderdrifter]

Getting rid of the misfire code would be awesome, but I need to fix the problem associated with the code, because it does bog/ misfire. If I read your post wrong, as a way to only remove the code appearing, my bad, I'll have to go reread it.

 

[gofer]

The misfire could be a number of things and should be troubleshot like its a failing part. Random cylinder misfires can be caused by poor wiring, a failing power transistor, coil pack, or CAS. Has this been an issue ever since you did the 6-bolt swap on your 2g or is it a recent occurence?
A few things you can do.

1. Spark plugs. Replace them (NGK BRP6/7ES) and gap them to 0.28"
2. Coil pack, IPT, & CAS. Heat them up individually with a blow dryer or heat gun while your car is idling, sometimes they fail when things start heating up under the hood.
3. DSM Friend. Hopefully you've got a few and they're willing to let you swap in their KNOWN working IPT and coils with you and see if the failure disappears.​

The reason why I'm quick to assume there ISN'T a failing part is because you've got a 2g ECU, which relies on a signal from both the CPS/CAS, and its only getting an actual signal from the 1g CAS which "simulates" the CPS. The reason why ECMLink is the only "fix" is because you can tell the ECU to basically ignore the misfire the ECU basically creates so the CEL won't get thrown.

 

[spyderdrifter]

The misfire could be a number of things and should be troubleshot like its a failing part. Random cylinder misfires can be caused by poor wiring, a failing power transistor, coil pack, or CAS. Has this been an issue ever since you did the 6-bolt swap on your 2g or is it a recent occurence?
A few things you can do.

1. Spark plugs. Replace them (NGK BRP6/7ES) and gap them to 0.28"
2. Coil pack, IPT, & CAS. Heat them up individually with a blow dryer or heat gun while your car is idling, sometimes they fail when things start heating up under the hood.
3. DSM Friend. Hopefully you've got a few and they're willing to let you swap in their KNOWN working IPT and coils with you and see if the failure disappears.​

The reason why I'm quick to assume there ISN'T a failing part is because you've got a 2g ECU, which relies on a signal from both the CPS/CAS, and its only getting an actual signal from the 1g CAS which "simulates" the CPS. The reason why ECMLink is the only "fix" is because you can tell the ECU to basically ignore the misfire the ECU basically creates so the CEL won't get thrown.

That makes more sense. I didn't do the 6-bolt swap, it was already done when I bought the car, but it wouldn't start when I bought it. Fixed that issue, and within the 2 days I got to drive it before the compression went out, it drove fine. Then I did the rebuild, changed the entire engine harness, etc... I didn't even find out it was a 6-bolt until then. Right now, the engine has just over 415 miles on it, and the misfiring has only been happening since maybe 150 miles. The entire spark system is new, except the IPT. The plugs are NGKs, but I don't know what part #. I probably need new ones since even though they never fired up the car until after the rebuild, they were black from usage to try starting the car prior to teardown. They look much better now, but probably need to be replaced again. Right now, the gap is between .25 and .30, my gapping gauge doesn't have .28 on it, so I gapped them to were the .25 gauge goes through, but the .30 won't.

I want to get ECMLink (or DSMlink if that's the same thing), but I've been more focused on getting the car to run right first. I don't even know how easy it is to use since I've never used it before.

If these issues can be eliminated with ECMLink, is there any damage that can happen if I keep driving the car like this (this is my DD since my other car is sceased up)?

 

[spyderdrifter]

The misfire could be a number of things and should be troubleshot like its a failing part. Random cylinder misfires can be caused by poor wiring, a failing power transistor, coil pack, or CAS. Has this been an issue ever since you did the 6-bolt swap on your 2g or is it a recent occurence?
A few things you can do.

1. Spark plugs. Replace them (NGK BRP6/7ES) and gap them to 0.28"


​

So I just went to O'Rieley's to run the part number for those plugs and it didn't show up in their computer system. They instead gave me the usual NGKs I get that have part # BPR6EKN.
Will these be just as good so long as I double check the gapping (they said the plugs were pre-gapped, but I always double check since I've bought pregapped plugs in the past that weren't even close to being right)?​

 

[gofer]

Every spark plug in a way is pre-gapped, but to what application? Always check spark plug gap before you put it in, ALWAYS! ALWAYS! ALWAYS!

http://www.dsmtuners.com/forums/newbie-forum/336200-resolved-diff-between-bpr6es-bpr6ekn.html

 

[spyderdrifter]

Every spark plug in a way is pre-gapped, but to what application? Always check spark plug gap before you put it in, ALWAYS! ALWAYS! ALWAYS!

http://www.dsmtuners.com/forums/newbie-forum/336200-resolved-diff-between-bpr6es-bpr6ekn.html

Thanks for all the plug info. I went back and they had a set avalible. Realized that I read the part# wrong and gave it to them like that the first time oh well, got them now. I'm gonna install them next weekend along with my new sensors that finally came in and a new section of wire harness I've been wanting to swap out. I'll let you all on here know how the plugs turn out, hopefully they'll make a difference. (Great vfaq too).

However, my car is still possessed with it's bogging/ misfiring crap. I'm inclined to take your advice toward trying to get DSMlink to reset whatever needs resetting(which will come after getting this newer transmission for $250). On that note though, my car still reaks of fuel when running, and Moday morning I went out to my car and there was a puddle of liquid under the car in front of the fuel neck. I didn't check to see if it was fuel, but assumed it was due to location, and how fast it was dripping (couldn't have been brake fluid, was too thin of a vescocity). So I didn't drive my car that day and just used my fiance's car, but later came back and all the dripping stopped, and still hasn't happened since. My car reaked of fuel prior to this happening though. Could the bogging be a possibility of the pump sending too much gas since I only have stock injectors with a Walbro 255 (I might be getting some Evo VIII 550's here soon)?