Post your sputter, mis-fire, buck, stutter, etc...

[Sacto-Spyder]

I just bought my car 2 weeks ago (its a bone stock 96gst) and had hesitation/stuttering above 3k rpms especially after boost kicked in. The previous owner had just installed new plug wires so I assumed that the plugs where replaced also. WRONG. I checked out the plugs and they almost looked rusted where the ceramic meets the metal. I replaced these with the NGK BPR6ES plugs as suggested by a previous member and bam! No more hesitation. It still feels slow but the hesitation is completly gone! Thanks guys!

 

[NightRider97]

Hey guys,
I'm new to the import crowd. I've built numerous old american V8s. Even a 4 digit hp chevy small block.
Anyway. basically I'm saying that I don't know squat about this car.

I just bought it off of e-bay and bought it knowing that the turbo needed replaced. It has a new motor and new trans axle but the turbo was left original because it had no shaft play at that time.
Anyway, I've got a new T25 to put in the car. But I'm beging to think that there is more than just one problem.

Issues: Anytime going up a steep hill at 55mph in 5th gear and giving the car 1/2 throttle or more the car bucks like crazy.
Anytime trying to give more than 3/4 throttle in any gear the car bucks like crazy.
Anytime the car gets past 5000rpm I can't notice any more bucking.
Cruising at any speed, every now and then I can feel a little miss and the head lights will dim at that instant.
Ive got a few more problems but I'll leave it at this for now.

Please give me some advice, I don't know where to start.
Like I said the new turbo is going in in the next week. But I'm certain that not all of the problems are related to that.

 

[ddavisaf]

Everyone having this kind of problem needs to first and fore most, run a Boost Leak Test.
Secondly, you need to make sure the spark plugs in the vehicle are NGK BPR 6ES gapped at about .028". Yes, NGK BPR 7ES will work for a mostly stock vehicle, however they will foul more quickly than will the 6ES plug.
So your boost leak test came out perfect? And you've got good plugs? Alright, now it's time to check the plug wires and the coil pack.
Grab yourself a multimeter and test the primary coil's resistance and the secondary coil's resistance. HERE is a guide to help.
Okay, so boost leak test, spark plugs, and coil pack all tested good. Have you tested your plug wires yet? Ohm them out. The max resistance should be 22k. Anything less than 22k ohms is acceptable.

Still having a problem?
Well, have you checked the knock sensor? It's located on the backside of the block below the intake manifold. If you see a black "goo" dripping from the knock sensor then you'll need to replace it.
Other things to look at include:
MAS
Fuel Filter
Weak fuel pump

Hopefully this'll help more than a couple of ya out there!

 

[DallasN2O]

OK.. I'm going to jump in here and see if you guys can figure this out.

I have a rebuilt 6 bolt with 700 miles on it. I have minor upgrades. 2G pistons, 1G rods, 255 pump, stock injectors, 2G turbo manifold, stock rebuilt turbo, 3'' down pipe with 30'' glass pack dumped toward ground w/ no muffler (sounds ok), datalogger, boost controller (right now set to 15 psi), aftermarket boost gauge, etc. I'm pretty sure my mods list is updated. Anyways.

I'm getting 43 counts of knock under accelleration. Even at stock boost levels. If I put the inductive timging light on each plug wire, numbers 1 and 3 do not blink consistently like they should. It's like they skip a blink once in awhile. The car is pulling timing like hell under that extreme knock count (of course). On the logger its showing as low as 0 degree on TIMA when knock reaches its max. I checked base timing and its set to 5 degrees BTDC. I'm running 92 octane premium.

I'm wondering if the strange mis-fire could be the cause of the extremely high knock count or if its PK. It is a new knock sensor. Also, the car will only idle until its warmed up. I have to unplug the IAC to keep the car running at red lights (idles at 2k). If I plug it in.. the idle bounces from like 900 down to 400 then dies. What do you guys think could be causing the knock and the random misfire or is one causing the other? Thanks.

 

[pickens]

the misfire is causing the knock. Fix the electrical first (coils, wires, grounds, etc).

 

[DallasN2O]

I'm just about fed up with this crappy stock ignition system.. can you suggest something to replace it? I was thinking coil on plug from SBR. Does the coil on plug setup still require the stock transistor box?

 

[Kaiden]

Looks like for the foremost we all have the same problem and its taking alot to fix it.

I have a 95 Eclipse GS non turbo DOHC. Recently i had replaced the pullies in the timing system and re-timed the car and im pretty sure all that is correct. afterwards i drove it for two weeks and then it started jerking hard.

I've replaced the spark plugs with bosch platinums and bosh plug cables but that didnt fix it. I replaced the valve cover seals and the plug seals thinking oil might be getting in on the plugs. It still didnt stop so i took it to Autozone and had it hooked up to a computer and it showed up that i had an EGR valve soleniod circuit problem and a fan control relay problem. I replaced the whole EGR and it still didnt fix it and so im out of ideas.

From reading the other posts people finding they're fixes within the plugs, plug wires and coils. My plugs and wires are brand new i spent $70 U.S for plugs and wires and had my coil pack tested at autozone and they said it passed. Can someone help?

 

[DallasN2O]

update: my problem was a broken injector.. replaced with 550s and upgraded 1G mas to a 2G mas and my problem is fixed.

 

[loveTOspeed]

My car used to sputter, misfire, and bog down all the freakin time. Well I changed out my spark plugs (twice), changed the wires, but I couldn't get the coils due to money woes. Later I found out that my BAROMETRIC PRESSURE SENSOR was giving me a CEL. I replaced my Mass Airflow Sensor (which is where the BAS is located on 1g's) and now my car runs great. Try changing that if the money is available.

 

[DallasN2O]

Same experience here. I had bucking and jerking and just plain unsmooth part throttle acceleration until I switched from 1G to 2G MAS and it was like nite and day. Runs way better now. I recomend everyone with a 1G to upgrade to 2G MAS.

 

[drift_raptor]

So i fixed my sputter/hesitation problem, i found out the guy i bought the car from had put iridium plugs in. changed them back to the $2 boch OEM plugs and the car runs great now.

 

[Raptoreborn]

This is by far the best thread ever. Just found it now.

My car hesitates between 3k-4k rpm range. My neo translates this to be around 70%-100% throttle. Any where between 45%-65% throttle it will hold strong up until 110mph and will hesitate upward from there. This is w/a big 16g. Now when I had the t25 it held the same symptoms accept it would sputter real bad after 80mph. Changed spark plugs/wires (gapped @ .028), new coil, and no boost leaks. I recently just installed the
b16g and for some reason (bad wiring on my part) the afc had the motor idle @ 2000rpm . The car had no hesitation problems and pulled like a monster. Why??
Well I just figure to give it more fuel in the 3k-4k range. A little better, but still hesitates.

 

[karbon]

Rather than post a new topic that fits under this thread I'll just put my problem here:

For months, I've had a stutter that does not throw a CEL, and does not show knock. It used to only happen when I went over around 10PSI. Then it started happening out of boost, around 3500 - 4000 RPM. Not it's creeped down around 2500 - 4000 and is joined by bucking. Since this problem arose, the tach needle twitches and the exhaust burps or misses at idle. A couple times the tach needle just drops to 0 after the car warms up, but this problem is intermittent. During this stuttering, the RPM signal is a little bumpy on DSMLink, but not enough to consider it a CrAS issue. During the stuttering under boost, the O2 pegs lean, and agrees with my wideband. If I max out my fuel sliders, I can get it to be as rich as 12.5 at WOT when it starts stuttering, but it stutters whether it's 18:1 or 12.5:1. (Yes, it reches 18:1 at WOT if I use the sliders I previously tuned the car with, still no knock though).

One thing to consider that may or may not matter is that after my MSD-DISII caught on fire I was running the bypass plug on the long harness and it was zip-tied to the main engine harness. Apparently the ziptie broke or something and the harness drooped and wrapped around my axle, yanking the ignition harness out of the coil pack plug, damaging the plug in the process. I've since soldered in a new plug.

So far I have replaced:
Wires with Accel Thundersport 300
Plugs, running BPR06-ES @ .028
Coil pack wiring from known good wiring from a bad coil pack
Coil pack plug
Power Transistor (also disassembled the connector to check for weak pins/connection)
Fuel filter
CrAS (BS Belt snapped and broke the old one)

The coil pack primary and secondary resistance is still within spec.
Boost leak test showed that it held 20psi just fine, slowly bleeding off the pressure

Still having problems, though. Any suggestions on what to suspect next?

 

[karbon]

Just grabbed a log of the bucking, keeping the throttle steady to cruise in 2nd gear. Spikes at 10,000 RPM while InjOn drops to 0ms. Is this how fuel cut looks on a log? It sure feels like it. It only does this for about 5 minutes of driving when the car is cold, then slowly subsides as the car warms up.

 

[habitatguy187]

When you figure this out let me know. As I've been searching the forums since I joined and still haven't fixed my car.

 

[zack4g63s]

I have a 95 gst and the car starts fine but runs and idles like crap. When you hit the gas it takes forever to gain rpm and usually wont go above 3500. I'm kinda new to these cars as this is my first Mitsu. I'm not sure if its a vacuum leak or what. I did notice the preveouse owner used red crimp connectors on the three wires for the cps(camshaft positioning senser)so I cut them out and soldered the wires but it made it no better. IDK I'm almost to the point of sellin it.

 

[boostedinthe843]

do a boost leak test, are you throughing a cel?

 

[JEFFREYCASTGSX]

One time when i was going home from work, i decided to get on it a little...hit full boost then shifted to second and right after let off the clutch it ran fine for half a second and then completely lost ALL power and had a NASTY misfire... i pulled over checked the motor and seen one of the plug wire came undone... put it back on and then left home right as i was getting around the block it happened again.... so i jammed it in there... got home took out the coil packs brushed off all the "grime"( that i think came from a not so good contact) put them back on and i was good to go....

 

[zack4g63s]

do a boost leak test, are you throughing a cel?

I had a cel for the maf, someone wired some kind of tuner into it. Then somewhere the line it got out leaving the orange wire cut for the maf. I resoldered it and the light went out.

but yea how do I do a boost leak test?

 

[boostedinthe843]

first you make a boost leak tester, its pretty simple, search the forums for it, theres a bunch of threads about it. dont forget to use soapy water when you do the test

 

[zack4g63s]

On the stock intake between the turbo and the maf theres two hoses, the small one goes to the valve cover, but where the heck does the other one go? I pulled it out by accident and now cant find where it came from.

 

[zack4g63s]

first you make a boost leak tester, its pretty simple, search the forums for it, theres a bunch of threads about it. dont forget to use soapy water when you do the test

Ok sweet I'll try that in themorning, thanks.

 

[Detective Coating]

My worst I just got fixed today after 2 months. I had a brand new Walbro 255 that I installed with all new AN lines, used Aeromotive AFPR, FIC 650's also used and I was having a horrible sputter and break up in any heavy load in 3rd gear or higher. I changed damn near everything that was used and all the seals in my sending unit and tried 3 new ones and finally came to find out that my brand new pump was bad. I couldn't believe when I put the stock pump back in that it worked perfect!

 

[turboboy4]

So I just installed upper and lower intercooler piping and a greedy rs bov, and now the car is bucking and almost sounds like its hitting the rev limiter as fast as its sputtering. The plugs and wires are ngk's and are only a month old. I was on the interstate with the cruise on and it would surge like it couldnt keep a steady speed. Wondering if I could possibly have a fuel pump going or a boost leak. I have to let the car idle for an extended amount of time in the morning just because it is so damn cold here so i was wondering if the plugs could be fouled already. Does it on hard acceleration

 

[Detective Coating]

So I just installed upper and lower intercooler piping and a greedy rs bov, and now the car is bucking and almost sounds like its hitting the rev limiter as fast as its sputtering. The plugs and wires are ngk's and are only a month old. I was on the interstate with the cruise on and it would surge like it couldnt keep a steady speed. Wondering if I could possibly have a fuel pump going or a boost leak. I have to let the car idle for an extended amount of time in the morning just because it is so damn cold here so i was wondering if the plugs could be fouled already. Does it on hard acceleration

You have a boost leak.