A question ... only experienced need reply
12-02-2005, 07:07 PM
#1
Senior Member
Thread Starter
Join Date: Jun 2002
Location: WA
Posts: 1,312
First I'll say this; I hate asking technical questions in teh 2nd gen forum because you get like 600 replies from dudes that have no idea what they are talking about, or are just plain goobers. So if you are gonna reply, atleast state WHY you think it might be the issue. Thanks!
Ok, so heres the deal. Spark plugs are fouling like crazy. 5-6 months ago the car was running fine, then one day driving it on a glorious sunny day, poof, wouldnt go above 4000rpm and started blowing blue/black smoke. I pulled into the nearest gas station to take a look. At first I thought the worst, thought I blew an oil seal completely. I park it at my friends house down the street and come pick it up early in the morning the next day to take to my garage. In the morning it ran fine ... until about 100 yards from my house.
After looking at it in my garage and doing a compression check, which yielded great results of above 110psi all around, I was a little happier. I had to leave the country like the next day, so I let the car sit for about 3 months.
When I got back I checked it out a bit more to find out that my spark plug wires were shot to hell. I replaced them, replaced the plugs and off I went. Everything was fine and back to normal! ... until...
about 3 hours of drive time when the plugs fouled up. I thought that was odd, so I took them out and cleaned them to a sprakling shine! 1 hour of drive time later, fouled up, car running super shitty.
And for a confirmation... I did it one more time, same results. So my question is... what do you figure it could be?
Cliff notes:
-------------
problems:
Car ran great
Car stops revving over 4k rpm (almost like it might have been in retard mode)
Car blows oil smoke at start (pooling oil?) but fine after warm up
Car fouls plugs faster than I can clean them (with oil and fuel)
Things I've tried or thought of and need confirmation:
I've checked the FPR to make sure no fuel was by passing and spraying down into the manifold.
I checked all ignition parts (coils are good, wires are good, plugs are good)
Engine compression is good
doesnt seem like the oil seals are broken
Fuel injectors are good
took the turbo off and no sign of leaky oil inside the turbo
rear exhaust port has a lot more oil stains than the front housing
I still have the OMP on and I'm about to go test its resistance, I'm thinking maybe one of the oil injectors on the rear is bad and is dumpping in massive amounts of oil. Is that possible? I know they are set to drip and have very small injector holes.
Anyways, anyone have any ideas on why the car would be running super duper rich with fuel and oil?
Also, I havent checked the o2 sensor yet, and I havent hooked it up to the wideband yet.
Ok, so heres the deal. Spark plugs are fouling like crazy. 5-6 months ago the car was running fine, then one day driving it on a glorious sunny day, poof, wouldnt go above 4000rpm and started blowing blue/black smoke. I pulled into the nearest gas station to take a look. At first I thought the worst, thought I blew an oil seal completely. I park it at my friends house down the street and come pick it up early in the morning the next day to take to my garage. In the morning it ran fine ... until about 100 yards from my house.
After looking at it in my garage and doing a compression check, which yielded great results of above 110psi all around, I was a little happier. I had to leave the country like the next day, so I let the car sit for about 3 months.
When I got back I checked it out a bit more to find out that my spark plug wires were shot to hell. I replaced them, replaced the plugs and off I went. Everything was fine and back to normal! ... until...
about 3 hours of drive time when the plugs fouled up. I thought that was odd, so I took them out and cleaned them to a sprakling shine! 1 hour of drive time later, fouled up, car running super shitty.
And for a confirmation... I did it one more time, same results. So my question is... what do you figure it could be?
Cliff notes:
-------------
problems:
Car ran great
Car stops revving over 4k rpm (almost like it might have been in retard mode)
Car blows oil smoke at start (pooling oil?) but fine after warm up
Car fouls plugs faster than I can clean them (with oil and fuel)
Things I've tried or thought of and need confirmation:
I've checked the FPR to make sure no fuel was by passing and spraying down into the manifold.
I checked all ignition parts (coils are good, wires are good, plugs are good)
Engine compression is good
doesnt seem like the oil seals are broken
Fuel injectors are good
took the turbo off and no sign of leaky oil inside the turbo
rear exhaust port has a lot more oil stains than the front housing
I still have the OMP on and I'm about to go test its resistance, I'm thinking maybe one of the oil injectors on the rear is bad and is dumpping in massive amounts of oil. Is that possible? I know they are set to drip and have very small injector holes.
Anyways, anyone have any ideas on why the car would be running super duper rich with fuel and oil?
Also, I havent checked the o2 sensor yet, and I havent hooked it up to the wideband yet.
12-02-2005, 07:38 PM
#2
Senior Member
Join Date: Apr 2004
Location: Garland, TX
Posts: 224
What year is the car? This would probably help the more experienced people on here.
***MY NON-EXPERIENCED OPINION***
Yes, you wanted experienced replies but the top part of my post is for that. I would check the OMP as well, I know that they dump more oil depending on throttle, so there is a chance that it is stuck at the WOT area.
Another thing is, have you checked the TPS? I remember posts on the other forum about running ungodly rich makes smoke similar to oil problems.
You say injectors are good, how did you check them? You're positive one isn't leaking?
***MY NON-EXPERIENCED OPINION***
Yes, you wanted experienced replies but the top part of my post is for that. I would check the OMP as well, I know that they dump more oil depending on throttle, so there is a chance that it is stuck at the WOT area.
Another thing is, have you checked the TPS? I remember posts on the other forum about running ungodly rich makes smoke similar to oil problems.
You say injectors are good, how did you check them? You're positive one isn't leaking?
12-03-2005, 12:09 AM
#3
Senior Member
Join Date: Feb 2003
Location: Rainy Seattle
Posts: 452
Series and induction type please?
How is your PCV system? Checked the h2o thermosensor lately?
Since you said you're going to check the OMP "resistance", I'm going to assume you've got a S5. An electronic OMP going south might explain the intermittent nature of it.
How is your PCV system? Checked the h2o thermosensor lately?
Since you said you're going to check the OMP "resistance", I'm going to assume you've got a S5. An electronic OMP going south might explain the intermittent nature of it.
12-03-2005, 12:49 AM
#5
Senior Member
Thread Starter
Join Date: Jun 2002
Location: WA
Posts: 1,312
sorry guys, the car is a 91 t2. Engine has been modified quite a bit and its running the stock ecu for the time being.
I checked the OMP and it was checked out ok as far as resistance. I didnt check the oil injectors though (which I should have, but I'll do that tomorrow)
You mentioned that the ecu runs rich when the water temp sensor goes bad? I've never run across this, however not too long ago when I was putting the engine in the car i broke the water temp sensor on the back of the water pump housing, a buddy of mine did the same with his s4 and had no ill effects, so I didnt bother with mine. Can you explain more on what happens when the ecu cant read that sensor?
I checked the OMP and it was checked out ok as far as resistance. I didnt check the oil injectors though (which I should have, but I'll do that tomorrow)
You mentioned that the ecu runs rich when the water temp sensor goes bad? I've never run across this, however not too long ago when I was putting the engine in the car i broke the water temp sensor on the back of the water pump housing, a buddy of mine did the same with his s4 and had no ill effects, so I didnt bother with mine. Can you explain more on what happens when the ecu cant read that sensor?
12-03-2005, 11:23 AM
#6
Senior Member
Join Date: May 2005
Posts: 959
Does the car still smoke at all, or is it just the plugs fouling now?
My first impression would have been the OMP was failing... as I've had a '91 NA's OMP go bad and the car wouldn't rev past 4K and smoked under 4K. The owner decided not to bother with it for another few weeks. He finally replaced the OMP, 3 months later he called me to come to his work and listen to his engine it had a "missfire"..I came by, popped the plugs out, and had NO compression on the rear rotor at all. Told him the news that his motor was done and that he needs a rebuild.
Reason for me saying this, is if your unsure what the problem is, especially dealing with the oil system, DON'T DRIVE, lol. Poor lubrication will dramatically reduce engine life. And based on the fact that you said you just put the motor in, I'm assuming you don't want to pull it back out.
An alternative for now would be to run premix. I run this in my car with standalone. I'm not 100% sure if the car will run w/out the OMP hooked up with stock ECUs, I've heard people say it will, others who say it won't. I've only done it on standalones. At least if you run premix, even with the OMP plugged in, at least you'll know your getting lubbed. I run 150:1 ratio...you could run a little less 125,100:1. If running premix yields a lot of smoke, your OMP may be working...and you could stop running premix.
Ok, i'll stop rambling...
My first impression would have been the OMP was failing... as I've had a '91 NA's OMP go bad and the car wouldn't rev past 4K and smoked under 4K. The owner decided not to bother with it for another few weeks. He finally replaced the OMP, 3 months later he called me to come to his work and listen to his engine it had a "missfire"..I came by, popped the plugs out, and had NO compression on the rear rotor at all. Told him the news that his motor was done and that he needs a rebuild.
Reason for me saying this, is if your unsure what the problem is, especially dealing with the oil system, DON'T DRIVE, lol. Poor lubrication will dramatically reduce engine life. And based on the fact that you said you just put the motor in, I'm assuming you don't want to pull it back out.
An alternative for now would be to run premix. I run this in my car with standalone. I'm not 100% sure if the car will run w/out the OMP hooked up with stock ECUs, I've heard people say it will, others who say it won't. I've only done it on standalones. At least if you run premix, even with the OMP plugged in, at least you'll know your getting lubbed. I run 150:1 ratio...you could run a little less 125,100:1. If running premix yields a lot of smoke, your OMP may be working...and you could stop running premix.
Ok, i'll stop rambling...
12-03-2005, 11:37 AM
#7
Senior Member
Thread Starter
Join Date: Jun 2002
Location: WA
Posts: 1,312
After cleaning the plugs, the car runs great. The only time it went into limp mode was back when the problem first started, and I think it was just the plug wires were shot and seemed like it was in lim mode.
It still does have a bit of smoke on start up, once warm the smoke goes away completely.
It still does have a bit of smoke on start up, once warm the smoke goes away completely.
12-05-2005, 04:44 PM
#8
Member
Join Date: Dec 2004
Posts: 75
maybe a failed o2 sensor?
when my sensor failed in my car, the car ran super rich to the point where i couldn't even get 400km of driving per full tank of gas.
your throttle position sensor might be FUBAR too.
have you checked the resistance on it?
when my sensor failed in my car, the car ran super rich to the point where i couldn't even get 400km of driving per full tank of gas.
your throttle position sensor might be FUBAR too.
have you checked the resistance on it?
12-05-2005, 06:54 PM
#9
Senior Member
Join Date: May 2002
Location: California
Posts: 22,465
Originally Posted by sidewinderx7' post='783398' date='Dec 2 2005, 10:49 PM
sorry guys, the car is a 91 t2. Engine has been modified quite a bit and its running the stock ecu for the time being.
I checked the OMP and it was checked out ok as far as resistance. I didnt check the oil injectors though (which I should have, but I'll do that tomorrow)
You mentioned that the ecu runs rich when the water temp sensor goes bad? I've never run across this, however not too long ago when I was putting the engine in the car i broke the water temp sensor on the back of the water pump housing, a buddy of mine did the same with his s4 and had no ill effects, so I didnt bother with mine. Can you explain more on what happens when the ecu cant read that sensor?
this is how the water temp sensor works
s3's (84-85 gsl-se), ecu looks at the sensor value and corrects as needed, if the sensor is unplugged it thinks its -32 degrees outside, and floods the motor, if its shorted it might not start, cause its too lean
s4's (86-88) same, but it might default to a preset value, car may or may not run ok
s5,6 (89-95) supposed to defualt to a normal value but it may or may not. we had an fd that would intermittantly flood or not start cause the sensor was going back and forth between working, shorting, and being unplugged.
long story short, it needs that sensor