LT1 Gremlins! Need help!
12-14-2007, 07:56 AM
#1
TECH Resident
Thread Starter
Join Date: Feb 2006
Location: Panama City Florida
Posts: 934
Likes: 0
Received 0 Likes
on
0 Posts
LT1 Gremlins! Need help! I am having some serious problems that are about to put me in an asylum. Here is the deal. My 95 TA is doing some weird things. 1'st off it is running real rough, I mean sputtering, backfiring and blowing black smoke. I changed the wires, plugs, and opti. When I did this it ran fine for about 1 mile and started up again. When I changed the plugs the 1st time all of the plugs on the passenger side were fouled out and black - all of the plugs on the driver side were fine. When hooked to a scanner no codes come up except for it says that it is running lean on the passenger side - even though the plugs on that side were fouled out! I need your help! Any ideas would be greatly appreciated. I am leaning towards o2 sensor on the passenger side reading wrong and putting too much fuel on that side. I have not tried it yet because I need your opinions 1st before I dump more money into this!!!
12-14-2007, 07:59 AM
#2
I am having some serious problems that are about to put me in an asylum. Here is the deal. My 95 TA is doing some weird things. 1'st off it is running real rough, I mean sputtering, backfiring and blowing black smoke. I changed the wires, plugs, and opti. When I did this it ran fine for about 1 mile and started up again. When I changed the plugs the 1st time all of the plugs on the passenger side were fouled out and black - all of the plugs on the driver side were fine. When hooked to a scanner no codes come up except for it says that it is running lean on the passenger side - even though the plugs on that side were fouled out! I need your help! Any ideas would be greatly appreciated. I am leaning towards o2 sensor on the passenger side reading wrong and putting too much fuel on that side. I have not tried it yet because I need your opinions 1st before I dump more money into this!!!
12-14-2007, 09:07 AM
#4
Probably not with those gaskets. I'd definitely check the 02s, but heres the deal, they will scan for free @AutoZone and when the 02s are bad you get a code, forget the # but everytime I scanned when mine would run rough (always ran rich) it would throw a code for whichever 02 bank, I'd replace it and was good to go. I had 02 simms after-CATs and would only replace the pre-CAT 02s.
12-14-2007, 09:42 AM
#5
12 Second Club
iTrader: (5)
Join Date: Jul 2006
Location: Tampa, Fl
Posts: 583
Likes: 0
Received 0 Likes
on
0 Posts
Is the car behaving this way when it is cold as soon as it starts up, or only once it warms up?
How does it behave under WOT?
If you are going to replace O2 Sensors, you might as well replace both. And on that note, if you are replacing O2 Sensors, only purchase the AC Delco sensors. Quite a few members in the past have used Bosch O2s found at a Local DAP and have had issues with them. The Bosch O2s don't relay readings quickly enough to the PCM for the car to run well in closed loop.
I would try unplugging the O2 sensors and seeing how the car runs. It will most likely take a couple of hours of driving for it to throw a code, but if the car runs better with them unplugged, then that is your culprit.
Double check your plug wires for burns and cracks, and with the car running super rich, it wouldn't hurt to replace the plugs while you're at it.
Also try running the car at night (with the lights out) with the hood open and see if you see any sparks. Sometimes lower quality plug wires will ground on other metal objects under the hood.
How does it behave under WOT?
If you are going to replace O2 Sensors, you might as well replace both. And on that note, if you are replacing O2 Sensors, only purchase the AC Delco sensors. Quite a few members in the past have used Bosch O2s found at a Local DAP and have had issues with them. The Bosch O2s don't relay readings quickly enough to the PCM for the car to run well in closed loop.
I would try unplugging the O2 sensors and seeing how the car runs. It will most likely take a couple of hours of driving for it to throw a code, but if the car runs better with them unplugged, then that is your culprit.
Double check your plug wires for burns and cracks, and with the car running super rich, it wouldn't hurt to replace the plugs while you're at it.
Also try running the car at night (with the lights out) with the hood open and see if you see any sparks. Sometimes lower quality plug wires will ground on other metal objects under the hood.
12-14-2007, 11:01 AM
#6
TECH Resident
Thread Starter
Join Date: Feb 2006
Location: Panama City Florida
Posts: 934
Likes: 0
Received 0 Likes
on
0 Posts
Is the car behaving this way when it is cold as soon as it starts up, or only once it warms up?
How does it behave under WOT?
If you are going to replace O2 Sensors, you might as well replace both. And on that note, if you are replacing O2 Sensors, only purchase the AC Delco sensors. Quite a few members in the past have used Bosch O2s found at a Local DAP and have had issues with them. The Bosch O2s don't relay readings quickly enough to the PCM for the car to run well in closed loop.
I would try unplugging the O2 sensors and seeing how the car runs. It will most likely take a couple of hours of driving for it to throw a code, but if the car runs better with them unplugged, then that is your culprit.
Double check your plug wires for burns and cracks, and with the car running super rich, it wouldn't hurt to replace the plugs while you're at it.
Also try running the car at night (with the lights out) with the hood open and see if you see any sparks. Sometimes lower quality plug wires will ground on other metal objects under the hood.
How does it behave under WOT?
If you are going to replace O2 Sensors, you might as well replace both. And on that note, if you are replacing O2 Sensors, only purchase the AC Delco sensors. Quite a few members in the past have used Bosch O2s found at a Local DAP and have had issues with them. The Bosch O2s don't relay readings quickly enough to the PCM for the car to run well in closed loop.
I would try unplugging the O2 sensors and seeing how the car runs. It will most likely take a couple of hours of driving for it to throw a code, but if the car runs better with them unplugged, then that is your culprit.
Double check your plug wires for burns and cracks, and with the car running super rich, it wouldn't hurt to replace the plugs while you're at it.
Also try running the car at night (with the lights out) with the hood open and see if you see any sparks. Sometimes lower quality plug wires will ground on other metal objects under the hood.
12-14-2007, 12:25 PM
#7
GREAT TIP!!! I thought that was some old-school BS when a buddy told me after I replaced an OPTI that was actually just fine...turned out to be a #5 plug wire resting on a header and burned...but sure enough at night it looked like a Blue Northern rolling into the panhandle, lightning everywhere.
Trending Topics
12-14-2007, 01:32 PM
#8
TECH Resident
Thread Starter
Join Date: Feb 2006
Location: Panama City Florida
Posts: 934
Likes: 0
Received 0 Likes
on
0 Posts
GREAT TIP!!! I thought that was some old-school BS when a buddy told me after I replaced an OPTI that was actually just fine...turned out to be a #5 plug wire resting on a header and burned...but sure enough at night it looked like a Blue Northern rolling into the panhandle, lightning everywhere.
12-14-2007, 11:48 PM
#11
Staging Lane
Join Date: Oct 2007
Posts: 65
Likes: 0
Received 0 Likes
on
0 Posts
for ***** and giggles, try and get your hands on another maf to see if that might have something to do with it...when mine went bad i thought it was bad gas for a while and just ran like crap
12-15-2007, 01:13 AM
#12
TECH Senior Member
iTrader: (3)
Join Date: Oct 2006
Location: Decatur, TN (N-W of Athens)
Posts: 7,564
Likes: 0
Received 3 Likes
on
3 Posts
I agree on bad gas. I'd do these thee things: Fuel Filter (cheap, $10-15), O2 Sensors (Both, or all three, don't just hope for the best with 1 or 2. The post-cat is less important, so at minimum the bank ones), after those two pull the plugs and clean them since not being that old they should clean off nicely and then make sure they're gaped right. Then go get a tank of quality gas. Or at least top it off with 92/93oc.
If you're still having problems, check the IAC, TPS idle-WOT voltage (.52-.58v - 4.0-4.5v), PCV valves (cover and side of intake). With the TPS, make sure your throttle is returning back to "0" and that it's not sticking, which would cause a bad TPS reading. Lube up both sides of the shaft (with the RPS off and throttle linkage side). Last I can think of would be the coil and spark control module (that finned thing next to the coil). Do them both at the same time and while you're there, use about 3-4 washers and space the SCM (ESC Electronic Spark Control) away from the head AND USE THE WHITE PASTE THAT COMES WITH IT! That is thermal compound and helps speak the heat to that heatsink (finned part).
After all that, all that comes to mind then is a vacuum leak, a bad/wonky MAF (trade a friend or run w/o it quick, since it'll run on MAP which is no problem), or a stuck open EGR.
(Sorry if I dumbed anything down too much, trying to cover everything and any possible mistake)
GL
PS Last thing I can think of, if you have an old cat let it run/idle for about 30mins (if I can), preferable at night as well, and see if the cat gets red. If so, it's plugged and time for a new one/straight pipe.
If you're still having problems, check the IAC, TPS idle-WOT voltage (.52-.58v - 4.0-4.5v), PCV valves (cover and side of intake). With the TPS, make sure your throttle is returning back to "0" and that it's not sticking, which would cause a bad TPS reading. Lube up both sides of the shaft (with the RPS off and throttle linkage side). Last I can think of would be the coil and spark control module (that finned thing next to the coil). Do them both at the same time and while you're there, use about 3-4 washers and space the SCM (ESC Electronic Spark Control) away from the head AND USE THE WHITE PASTE THAT COMES WITH IT! That is thermal compound and helps speak the heat to that heatsink (finned part).
After all that, all that comes to mind then is a vacuum leak, a bad/wonky MAF (trade a friend or run w/o it quick, since it'll run on MAP which is no problem), or a stuck open EGR.
(Sorry if I dumbed anything down too much, trying to cover everything and any possible mistake)
GL
PS Last thing I can think of, if you have an old cat let it run/idle for about 30mins (if I can), preferable at night as well, and see if the cat gets red. If so, it's plugged and time for a new one/straight pipe.
12-15-2007, 03:48 AM
#13
Fuel filter is not going to cause sputtering or fouled plugs on only one side. I know this is cheap, but it does not apply to every situation. 
There are only 2 sensors on his car (and all pre-96, except for cali 95 cars).
I would tend to agree that O2 sensors might be your issue though. Either that or an exhaust leak or some other condition only affecting that side.
One thing you can try is to unplug one of the o2 sensors, if it runs better, then that is likely the problem.
I would tend to agree that O2 sensors might be your issue though. Either that or an exhaust leak or some other condition only affecting that side.
One thing you can try is to unplug one of the o2 sensors, if it runs better, then that is likely the problem.
Last edited by infinitebird; 12-15-2007 at 04:14 AM.
12-15-2007, 05:50 AM
#15
TECH Senior Member
iTrader: (3)
Join Date: Oct 2006
Location: Decatur, TN (N-W of Athens)
Posts: 7,564
Likes: 0
Received 3 Likes
on
3 Posts
People buy cars from all over. Doesn't hurt to cover all the bases. That, and my friends 94 Vette has post cat O2.
12-15-2007, 02:35 PM
#16
TECH Resident
Thread Starter
Join Date: Feb 2006
Location: Panama City Florida
Posts: 934
Likes: 0
Received 0 Likes
on
0 Posts
Thanks everyone! I will try out all the advise everyone hear is saying, I just replaced the o2 sensors and still have a problem. I guess on to the next suggestions . Formula 350 - I need things dumbed down a little at this point so explanations are much appreciated! Any other advise will be appreciated in that it will give me more things to try and resolve the issue.
I guess on to the next suggestions . Formula 350 - I need things dumbed down a little at this point so explanations are much appreciated! Any other advise will be appreciated in that it will give me more things to try and resolve the issue. 
12-15-2007, 03:16 PM
#18
TECH Resident
Thread Starter
Join Date: Feb 2006
Location: Panama City Florida
Posts: 934
Likes: 0
Received 0 Likes
on
0 Posts
New info that might help some one help me. The car does this at start up and seems to get slightly worse when warmed up. I dont think it is bad fuel because I filled up with a fresh tank of 93 and and the plugs were fouled only on the passenger side. I wonder if I should try to reprogram my cars computer. I also noticed that everything seemed to be fine right before I had the stall converter put in. I noticed it after I got the stall and it got real bad a couple of days after I ran a few passes at the local track. (not sure if any of this matters). Some one told me I could of burnt a valve and it could be the cause of my problems - I think that does'nt make any sense. Any thoughts on this as well?
