this can't be healthy

[Ottoman]

I've included a pic, to better describe what i mean

basically everyday when I start up and warm my car, i can sit next to the exhaust and watch all kindsa black carbon/soot/ maybe oil? forming on the ground... the water vapor carries it out... and there'd be lotsa white smole (cold mornings assumed it was just moisture condensing)

the other day i started the car during a sunny afternoon and still white smoke

when I rev the car there's black/greyish smoke puffing out... (I think I puff between shifts as well)

and if i bacl up near a wall and rev, I leave huge black spots on the wall..


I'm guessing i'm running retardly rich (car has no fuel mods, don't see how this could be an issue)

my Turbo is shot and needs to be changed..

the car's performance is deffinately less then stock..

so what do u guys think it is?

 

[25psi]

A bad o2 sensor will make you run really rich even on the stock fuel system.

 

[rowlex]

that stuff on the wall...is it wet or dry?? Yesterday I noticed my car does the same thing although not as much. Just a good size black spot after idling for 7-8 mins (warm up)

 

[GTM]

A bad o2 sensor will make you run really rich even on the stock fuel system.

Yes, you are right. Also a temp sensor thinking the engine is cold, high fuel pump pressure, bad spark plugs and wires, leaking injectors, and a bunch of other things.

Has he checked for any codes? The bottom line is he has to investigate and give us more info.. Has gas mileage decreased? Is this new condition or existing.

Cheers,
GTM

 

[Ottoman]

Thanks for the input.

I change the spark plugs at every oil change NGK BRP6ES gapped to .028 etc....

I do notice they get covered in carbon and get "blacK' within the same day (after driving 10-15 miles I pulled the plugs and they were blackish around the threads already)

I'm using MSD 8.5mm spark plug wires as well...

the "spot" starts wet, and becomes "dry" and stays there... almost like a powder..


I have no CEL's... I thought when the O2 sensore craps out, it throws a CEL. my A/F gauge cycles back and forth normally like it would at cruising speeds (tho it never pegs full rich, only lights up the first "green" bar of rich after stoich never all the way tho

My gas mileage is kinda crappy (tho having no base of comparison I wouldn't know what it was "supposed" to be)

I've only owned the car for 3 months or so... it's been this way since i bought it...

car idles fine...

i do notice gurgling and some popping like backfiring when i'm rolling to a stop in gear... thought it was just the by product of having 2.5 inch exhaust with no cat's...

also the car does seem to "burp" and shudder while sitting idle.... (i know it's a missfire cuz i can feel a slight vibration in the car when it happens and not just a regular backfire)

 

[rowlex]

Sounds like its just unburnt fuel, since there's no oil-residue..

Reason: No cat

 

[Ottoman]

Sounds like its just unburnt fuel, since there's no oil-residue..

Reason: No cat

I dunno man, I don't think it's that simple... (i know i'm not the only guy here running no cats i hope they can comment too)

and it still doesn't explain the lack of performance and the missfires...

I'm starting to wonder if I have a few thigns happening at the same time

 

[GTM]

I dunno man, I don't think it's that simple... (i know i'm not the only guy here running no cats i hope they can comment too)

and it still doesn't explain the lack of performance and the missfires...

I'm starting to wonder if I have a few thigns happening at the same time

Here in Calif these cars are classified as gross polluters though newer have fewer probs. The carbon / soot you mention on the ground is not uncommon. That doesn't mean it's right but not for sure impending doom.

It takes a lot more mile than you think to burn it off spark plugs and just a few min of driving for sure won't do it. Overtightining plugs can cause them to drop 1/2 heat range. Too wide a gap will make them burn hotter(cleaner?), get better gas mileage but poor acceleration and the converse is true.

Yes, it is entirely possible you do have more than one problem. The only way to sort this out is to go over some of the previously mentioned items including timing.

Cheers,
GTM

 

[Ottoman]

Here in Calif these cars are classified as gross polluters though newer have fewer probs. The carbon / soot you mention on the ground is not uncommon. That doesn't mean it's right but not for sure impending doom.

It takes a lot more mile than you think to burn it off spark plugs and just a few min of driving for sure won't do it. Overtightining plugs can cause them to drop 1/2 heat range. Too wide a gap will make them burn hotter(cleaner?), get better gas mileage but poor acceleration and the converse is true.

Yes, it is entirely possible you do have more than one problem. The only way to sort this out is to go over some of the previously mentioned items including timing.

Cheers,
GTM

I didn't quite understand ur 2nd paragraph... What i meant was, I put brand new white plugs into my car, and with only a short mileage on the car, the threads are all black...
I gapped the plugs correctly to 0.028" and wondered if that was normal, How do I know how much tightness is TOO much? I usually hand tighten them until they don't turn freely

I have a 2g so timing is ecu controlled.. I can't do anything about that... though i did buy a timing gun, and at idle it's around 9*

could it be the coil pack? anyway I can test it, without just replacing it?

 

[GTM]

I didn't quite understand ur 2nd paragraph... What i meant was, I put brand new white plugs into my car, and with only a short mileage on the car, the threads are all black...
I gapped the plugs correctly to 0.028" and wondered if that was normal, How do I know how much tightness is TOO much? I usually hand tighten them until they don't turn freely

I have a 2g so timing is ecu controlled.. I can't do anything about that... though i did buy a timing gun, and at idle it's around 9*

could it be the coil pack? anyway I can test it, without just replacing it?

2nd paragraph should have been it takes a lot more miles than you might think to burn the soot/carbon off the plugs. I presume you are talking about the threaded portion exposed in the combustion chamber and not all the way up the threads.

When inexperienced a torque wrench is used though I've seen printed instructions that give a specific percentage of a turn once the gasket contacts the seat. A guess would be in the 12-15 ft lbs. range but I don't have manual.

Yes and no, the CAS can be moved for initial timing.

Certainl a failing coil pack could cause this, testing will have to come from the manual's instructions. You really need a repair manual to test some of the things suggested for I'm getting too old to be a walking encyclopedia.

Cheers,
Gene

 

[sweetjumper32]

I'm having this same exact problem right now. I have everyone of these symptoms, and I'm fairly sure it is an o2 sensor. I have no CEL on, nor have I ever had a CEL (which leads me to believe the bulb may be removed/also, I've heard o2 sensors may not throw a CEL if the sensor is sporatically working), BUT, I took my car to Knechts and they pulled codes for me, one read, fuel trim malfunction bank 1, or something of the sort. I've decided to replace the o2 sensor before the cat. I am almost 100% positive this is my problem. Symptoms:

-13-16 mpg.
-Hesitant acceleration
-Powder like yours out my exhaust
-Backfires on decel.
-Horrible fuel smell, even inside the car.

My spark plugs also become carbon covered after just minutes, I've yet to find out if this could be related to a bad o2 sensor. I have one on the way right now, if it fixes my problems similar to yours, I'll let you know. Good Luck.

 

[Ottoman]

I'm having this same exact problem right now. I have everyone of these symptoms, and I'm fairly sure it is an o2 sensor. I have no CEL on, nor have I ever had a CEL (which leads me to believe the bulb may be removed/also, I've heard o2 sensors may not throw a CEL if the sensor is sporatically working), BUT, I took my car to Knechts and they pulled codes for me, one read, fuel trim malfunction bank 1, or something of the sort. I've decided to replace the o2 sensor before the cat. I am almost 100% positive this is my problem. Symptoms:

-13-16 mpg.
-Hesitant acceleration
-Powder like yours out my exhaust
-Backfires on decel.
-Horrible fuel smell, even inside the car.

My spark plugs also become carbon covered after just minutes, I've yet to find out if this could be related to a bad o2 sensor. I have one on the way right now, if it fixes my problems similar to yours, I'll let you know. Good Luck.

I keep pondering over this...

o2 sensor was one of my suspicions Tonight I'm gonna try unplugging the sensor and see if anything changes at all... if not, then it's probably a good sign that it is...

i'm also thinking:

CEL is disabled
Fuel pressure regulator
Leaky fuel injectors..
coil pack


My DSM is an import in this part of the world.. so spares are hard to come by.. I generally have to order from the states.. I'd hate to replace things that don't need replacing for nothing.. I'm saving up for a DSMlink+ECU so I don't wanna shell out for a pocketlogger that i wont use for very long...


Please let me know what happens... i'd really appreciate it

 

[GeneralChaos]

o2 sensor shouldnt be the only problem causing this. when I bought my car the o2 sensor before the cat wasnt working so a CEL light was on and it never threw out soot like that.

Id suggest pulling some codes because someone may have removed the bulb or just disabled it.


and isnt a lot white smoke out of the exhaust usually mean a gasket (like the head gasket)?

as for the horrible fuel smell, I used to have that in my car....and BAD. I would get high and smell like gas in my car, wasnt very safe in there. I removed the back seat and opened the plates and took off the stuff holding in the fuel pump and gauge level. on the fuel pump side the black rubber ring seal/gasket wasnt on correctly, after putting it on right and then airing the car out, its been smellin nice and fresh.

 

[suicidal2af]

o2 sensor shouldnt be the only problem causing this. when I bought my car the o2 sensor before the cat wasnt working so a CEL light was on and it never threw out soot like that.

Id suggest pulling some codes because someone may have removed the bulb or just disabled it.


and isnt a lot white smoke out of the exhaust usually mean a gasket (like the head gasket)?

as for the horrible fuel smell, I used to have that in my car....and BAD. I would get high and smell like gas in my car, wasnt very safe in there. I removed the back seat and opened the plates and took off the stuff holding in the fuel pump and gauge level. on the fuel pump side the black rubber ring seal/gasket wasnt on correctly, after putting it on right and then airing the car out, its been smellin nice and fresh.

The o2 sensor before the cat doesn't serve the same purpose.

 

[GeneralChaos]

The o2 sensor before the cat doesn't serve the same purpose.

I thought they were referring to the one before the cat

 

[Ottoman]

here's an update:

first off, i took a pic of one of my plugs to show u guys and u can tell me if u think it's fouled, running rich or alright...

2nd:

I decided to pursue the o2 sensore theory.... I first unplugged the MAS, and checked.. the CEL did come on.. so I know the CEL is working... i plugged the mas back in, CEL went off...

I then proceeded to unplug the primary o2 sensor located in the DownPipe... nothing seem changed, I looked and there was NO CEL...

I took the car out for a test drive.. and noticed an Immideate improvement... running start in first made me lose traction, and a hard chirp into 2nd...

the car was running faster with NO o2 sensor plugged in

i started pondering.. and remembered the problem associated with the "blue wire mod"

when I purchased the car, it came with an Autometer Boost and A/F gauge... I always wondered where the A/F was tapped in.. cuz i had removed the ECU once to check for an Eprom and none of the ecu wires were tampered...

Turns out the previous owner had tapped into the 02 right after the o2 plug of the harness side... I disconnected the A/F wires and left the o2 sensor plugged in...

tire squeeling effect still stayed...

the car seems to pull better now.. but i still feel it's dying from 3rd gear on.. and the gears feel really long... (my speedo doesn't work so i only can go by how "fast" i finish gears and the authentic butt dyno) another thing i noticed when I was turbo timing was the idle had gone down another 100rpm or so... 600-650ish i'm guessing.. car wasn't shuddering or vibrating excessivily.. seemed smooth....

when I drive the car tommorrow to work and around town, i'll see if the A/F gauges removal made a permanent diff or just a coincidence... (i notice the performance is AWEFUL during the day, lotsa hesitation, would feel like timing was being retarded ALL the way and stuff... and i'll check the exhaust for more carbon clouds)

one other thing.... I have a European DSM (amber tail lights, big side mirrors, no emmissions control etc.)

I noticed on my car, the o2 sensor's wire reachs up and over the heat shield down under the head near the exhaust cam side and attaches there to the block above the tranny, and attaches to the harness... (the heat shield is OEM and it comes with 3 "clips" to route it over itself so i know it supposed to be that way)

The US spec's o2 sensor doesn't cross over the exhaust shield, i dunno where your guys goes.. maybe it's diff... *shrug*

 

[GTM]

here's an update:

first off, i took a pic of one of my plugs to show u guys and u can tell me if u think it's fouled, running rich or alright...

Did anything get resolved with this?

I did get a look at the plug picture and notee a couple of things which may be meaningful.

The plug is sooted from cold and rich running, I don't know how many miles it took for insulator to burn clean but some of that is normal but too rich.

What I don't like is the eyebrow I see on the porcelain unless that's a camera shadow. I _rarely_ ever maybe never see this on fuel injected cars. Yes with carbs but not efi, it's caused by raw fuel when the valve starts to open hitting in the same place and leaving small deposits that never burn off. I use to be able to look at a plug and tell you what gas you were buying by the color of that eyebrow.

I don't know if this has always been common with your car for just that cylr or if it's part of the problem you were having. This could be a symptom of an injector problem, too cold a plug, cold start temp measurment or the engine not getting up to proper temp. Tell me it's a shadow...

Cheers,
GTM

 

[sweetjumper32]

Well I posted above, with my listed problem, and I'm happy to say. EVERYTHING IS BETTER! Changed my o2 sensor, and immediately noticed the difference. No backfire, no fouled spark plugs, no smell of gas inside my car, and best of all, no 14 mpg!! (got 25mpg after a 160 mile drive). I should note that my car did throw a Fuel Trim Malfunction Bank 1 code for this problem. Hope this helps.

 

[Silver2GST]

GTM, I'm trying to set the timing on my 2G (1995) GST. I have a 6-bolt motor installed so i CAN adjust my timing, But my laptop got stolen so no datalogger.

I have read that there is a plug on 95/96 cars to stop the ecu from adjusting timing, allowing you to use a normal timing light gun to set the timing.

any ideas? my car is running pretty nasty so i want to rule out timing.

 

[GTM]

GTM, I'm trying to set the timing on my 2G (1995) GST. I have a 6-bolt motor installed so i CAN adjust my timing, But my laptop got stolen so no datalogger.

I have read that there is a plug on 95/96 cars to stop the ecu from adjusting timing, allowing you to use a normal timing light gun to set the timing.

any ideas? my car is running pretty nasty so i want to rule out timing.

You are pushing your luck with my knowledge of specifics such as this. If you don't get an answer to this in the next day or so send up a red flag and I'll draft some more help.
...............

That said, the CAS is slotted on a 1G but I don't know what rewire or ECU mods/change were done to make it work for your installation. Were it not for this and the knock sensor you would be home free.

I have no idea of the claims I see for other cars on eBay for example. Some are charging as little as $1 for a resistor to be installed in a specific location which fools the ECU into thinking it has different running conditions. I would do my best to not change anything on the knock sensor since this is a fail safe device unless you KNOW exactly what you are doing. You just don't want to know how fast you can melt a hole in a piston on a high performance engine. I don't do mods for a variety of reasons including reliability and the problems they can add when troubleshooting a problem.

Did that help any?

Cheers,
GTM

 

[Silver2GST]

I won't do anything to the knock sensor. I just wanted to know if you knew how to set the base timing with a timing light. on a 1G you ground the plug on the firewall, this disables any ECU advance so you can set the true base timing with a timing light.

I read that you can do this on 95/96 DSMs but haven't had any luck. If you know anyone with a 6 bolt swap into a 95/96 ask if they know whats up with setting the base timing with a timing light. thanks