Here we go again....
03-02-2011, 09:14 PM
#21
Burning Brakes
03-02-2011, 09:31 PM
#22
Well, I also fixed a vacuum leak that may or may not have had something to do with that. The miss I heard at idle was only occasional, and not constant. I havn't even noticed it recently. I don't know what to do now. I don't have any problems with the brakes, but could there still be a vacuum leak in the booster? ECM problems? Plugged cat?
Last edited by tehcarguy; 03-02-2011 at 09:37 PM.
03-03-2011, 07:49 AM
#24
Instructor
Member Since: Dec 1999
Posts: 112
Likes: 0
Received 0 Likes
on
0 Posts
I went through a similar situation with an '85 we had years ago. We bought it used and it had been "tuned up" before we got it by one of those quick tune up places that used to be around...Milex, I think it was.
I did a lot of the things that you did troubleshooting, but what fixed it was replacing the new aftermarket plug wires with authentic GM ones.
Ran perfectly after that!
I did a lot of the things that you did troubleshooting, but what fixed it was replacing the new aftermarket plug wires with authentic GM ones.
Ran perfectly after that!
03-08-2011, 12:03 PM
#27
Racer
so if I read the posts now you're running fine and not missing at all during idle and low-load situations, but when you put a big load on it then you're missing/bucking/running rough?
High load / higher RPM problems are a lot of the times fueling related - when is the last time the fuel filter was replaced? How's the fuel pressure when it's acting up? (you'll need a gauge to monitor it).
Typically if it's a clogged converter it will seem to run OK but really struggle to get up into the higher RPM range and some times the exhaust will sound "hissy"
High load / higher RPM problems are a lot of the times fueling related - when is the last time the fuel filter was replaced? How's the fuel pressure when it's acting up? (you'll need a gauge to monitor it).
Typically if it's a clogged converter it will seem to run OK but really struggle to get up into the higher RPM range and some times the exhaust will sound "hissy"
03-08-2011, 10:59 PM
#29
Team Owner
Member Since: Mar 2001
Location: Cincinnati, Oh USA
Posts: 53,930
Likes: 0
Received 26 Likes
on
23 Posts
Pull the distributor cap and look inside for a carbon track or a crack. Look at the carbon button in the center for being in good condition. Look at the rotor, there is a hemispherical depression at its center, check that depression for a carbon track. Pull a plug wire and bring a grounded wire close to the plug boot and have someone crank the engine. You should have a snappy at least 1/2" spark. Plug wires must have good condition wire looms and the plug wires must not be touching metal, check the wire dressing. GM plug wires should measure about 5000 ohms per foot. Turn off the underhood lights and at night engine idling, look for sparks along each plug wire, there aren't supposed to be any.
03-21-2011, 01:37 PM
#30
Pulling the plugs and found #2 completely fouled. When I replaced the injectors i found one that was completely clogged, but didn't take note of wich cylinder it was for. I'm guessing it was this one. Is cleaning good enough or should I replace the plugs? Thank you all so much for the help!
03-21-2011, 03:18 PM
#31
So I cleaned that plug, and went for a very nice ride. Car runs perfectly now and idle is very smooth. Over a month of searching for this problem and it was all down to one plug...thanks again guys.
03-21-2011, 04:27 PM
#32
Racer
Good to know and even better that you let us know what the fix was!
Now... If it was black oily fouled, then your probablem may come back, but at least you'll know where to start. It may have a pooched valve seal allowing too much oil ingestion on that cylinder so it may foul again. If it does, just throw a new plug at it until you have time to do all the valve seals..
Greg
Now... If it was black oily fouled, then your probablem may come back, but at least you'll know where to start. It may have a pooched valve seal allowing too much oil ingestion on that cylinder so it may foul again. If it does, just throw a new plug at it until you have time to do all the valve seals..
Greg
03-22-2011, 02:32 PM
#33
Intermediate
Member Since: Jan 2011
Location: San ANtonio Texas
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
It sounds a lot like a coil/wire/plug issue. It will not throw a code until things get really bad.
If you have eliminated the TPS and timing issue, use a multi meter on the coil and insure it is to spec. Then get a spark tool that connects to your plug boot and visually make sure you are getting strong fire to each cylinder, especially the farthest ones from the coil. $10 bucks or less at the parts store.
Then start changing out wires with good ones. Finally, make sure you have the right plug (i.e. heat range, gap etc.) A fouled plug can be as bad as an arcing wire.
I doubt you have a cam timing issue associated with a worn or stretched timing chain. Cams can be advanced and retard a great deal without causes a miss. But if it makes you feel better, you can replace it for less than $50 bucks. Buy a Comp Cams cam plate for $4.95 from Summit that locks your cam bolts in place if you are paranoid (like me).
If you have eliminated the TPS and timing issue, use a multi meter on the coil and insure it is to spec. Then get a spark tool that connects to your plug boot and visually make sure you are getting strong fire to each cylinder, especially the farthest ones from the coil. $10 bucks or less at the parts store.
Then start changing out wires with good ones. Finally, make sure you have the right plug (i.e. heat range, gap etc.) A fouled plug can be as bad as an arcing wire.
I doubt you have a cam timing issue associated with a worn or stretched timing chain. Cams can be advanced and retard a great deal without causes a miss. But if it makes you feel better, you can replace it for less than $50 bucks. Buy a Comp Cams cam plate for $4.95 from Summit that locks your cam bolts in place if you are paranoid (like me).