SC running problems
12-29-2003, 12:29 AM
#1
Instructor
Thread Starter
SC running problems
Hi,
My '82 SC has developed a stumbling / hesitation problem. The car runs well cold, but as it warms up it begins stumbling terribly at lower rpms. It feels down on power as well, but I generally think that this is because the bucking makes acceleration somewhat difficult
The problem is worse the more throttle I give it- ie. by feathering the throttle very carefully & accelerating v. gradually I can avoid it. At higher rpms I can get away w/ more throttle, but I still get stumbling at WOT. It seems worse after rain, or when damp, but again it doesn't happen when cold, only once the temp gets above 160 or so.
I pulled the plugs & they were black, figured maybe this was because I'd just driven around the block cold, so warmed it up running at 3500 under load then cut it off checked again & they were white.
At warm idle pulling down & pushing up the sensor plate make the idle worse, so I would assume mixture is in the ballpark? I would think ignition, but can't see why things go so well when cold??
Any suggestions?
Andrew
My '82 SC has developed a stumbling / hesitation problem. The car runs well cold, but as it warms up it begins stumbling terribly at lower rpms. It feels down on power as well, but I generally think that this is because the bucking makes acceleration somewhat difficult
The problem is worse the more throttle I give it- ie. by feathering the throttle very carefully & accelerating v. gradually I can avoid it. At higher rpms I can get away w/ more throttle, but I still get stumbling at WOT. It seems worse after rain, or when damp, but again it doesn't happen when cold, only once the temp gets above 160 or so.
I pulled the plugs & they were black, figured maybe this was because I'd just driven around the block cold, so warmed it up running at 3500 under load then cut it off checked again & they were white.
At warm idle pulling down & pushing up the sensor plate make the idle worse, so I would assume mixture is in the ballpark? I would think ignition, but can't see why things go so well when cold??
Any suggestions?
Andrew
12-29-2003, 01:55 PM
#3
Instructor
Thread Starter
Thanks Loren. I will order a CIS tester & check that out. I've also noticed shorting in 1 or 2 of the OE plug wires when damp. I think it would be worthwhile to replace these w/ magnecors? Would I be right in hypothesising that if the mixture is too lean when warm that the hesitation would be worse when wet because of a weaker spark?
thanks!
thanks!
12-29-2003, 02:12 PM
#4
The spark energy from the coil should not be any weaker/less when a damp
condition exits. The problem occurs when moisture causes bad plug wires and/or
the dist. cap to breakdown (short to the engine). Any ignition voltage breakdown
is real problematic for a good running engine.
Check out this website (www.systemsc.com) on the Diagnostics page under
Poor Running for some additional info.
Have Fun
Loren
'88 3.2
condition exits. The problem occurs when moisture causes bad plug wires and/or
the dist. cap to breakdown (short to the engine). Any ignition voltage breakdown
is real problematic for a good running engine.
Check out this website (www.systemsc.com) on the Diagnostics page under
Poor Running for some additional info.
Have Fun
Loren
'88 3.2
