| Author |
Message |
stacy o'blenes (Stacy)
New member
Username: Stacy
Post Number: 42
Registered: 8-2001
| | Posted on Thursday, April 04, 2002 - 5:34 pm: | |
Henryk,
My car wasn't running well last fall due to a couple fouled plugs. When I put my timing light on the wires going to those plugs, it didn't light up. I think maybe if the plug is badly fouled there might not be enough voltage through the wire to trigger the inductive pickup. When I changed the plugs the light worked again.
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1988 TR (Henryk)
New member
Username: Henryk
Post Number: 13
Registered: 8-2001
| | Posted on Wednesday, April 03, 2002 - 9:48 pm: | |
Wouldn't a timing light work best to determine if a spark plug wire is bad? It must be an inductive "clip-on" type. Just watch the flashing lights. Even if a spark plug is bad, the light should still go on. |
Rob Lay (Rob328gts)
Board Administrator
Username: Rob328gts
Post Number: 1349
Registered: 12-2000
| | Posted on Thursday, March 28, 2002 - 10:34 am: | |
Well, I didn't have any problems knowing which wire went to which cylinder since the lengths are all different and the wires have a numbered band on them.
I just wanted to make sure I clicked them back on the plugs correctly and they were making contact. They must be, because it sounds and drives the same, just making sure.
Thanks! |
Richelson (Richelson)
Member
Username: Richelson
Post Number: 658
Registered: 12-2001
| | Posted on Thursday, March 28, 2002 - 9:15 am: | |
I agree that pulling plug wires is the best way but it may not be as easy to do on a QV as it is on a carb 308. The main item you want to listen for is an audible change in engine rpm. It should drop when the plug wire has been removed if the cylinder is firing properly. |
magoo (Magoo)
Intermediate Member
Username: Magoo
Post Number: 2171
Registered: 2-2001
| | Posted on Thursday, March 28, 2002 - 9:10 am: | |
Peter, the numbers on each cap go to that particular cylinder as it is stamped on the head. No. 1 on the cap to No. 1 on the stamped No. 1 on the head. They do not go according to the firing order. But if he pulled them and the length of the wires was correct before it should go back without much question. |
Greg Rodgers (Joechristmas)
Junior Member
Username: Joechristmas
Post Number: 172
Registered: 3-2001
| | Posted on Thursday, March 28, 2002 - 5:50 am: | |
I always just pull the plug wire when the engine is running and if I here a change in rpm then I know that cylinder is firing. I usually just pull them with my hand but it is much safer if you use a pair of pliers with rubber handles or plug wire pullers with cork. |
'75 308 GT4 (Peter)
Intermediate Member
Username: Peter
Post Number: 1730
Registered: 12-2000
| | Posted on Thursday, March 28, 2002 - 2:40 am: | |
You will know, feel and hear when the engine isn't running on all cylinders.
If you mis-wired your engine (a few wires) it'll run like crap. I've noticed that these QV and 328 motors have neatly trimmed, closely spaced wires, I think you'd know, based on the length alone, which wire goes where (unless you pulled the wires completely out from the cap, then you'd have to trace the firing order with cap hole sequence).
ATTENTION: The numbers on the caps (at least on my 308) do not correspond with cylinder firing order!!! If I remember, 1 and 4 are correct, 2 and 3 are backwards. If in doubt, start with number one, then going in the rotation of the rotor, the firing order (Destra: 1-3-4-2, Sinistra: 5-7-8-6) |
magoo (Magoo)
Intermediate Member
Username: Magoo
Post Number: 2169
Registered: 2-2001
| | Posted on Wednesday, March 27, 2002 - 11:42 pm: | |
Rob, I think your Dist. cap has the number of which plug wire goes where. Trace it down from the cap to the plug wire and install to the proper cylinder. Just a thought. Magoo |
Jorma Johansson (Jjfinland)
Junior Member
Username: Jjfinland
Post Number: 153
Registered: 3-2001
| | Posted on Wednesday, March 27, 2002 - 11:25 pm: | |
Rob, just let the engine idle and hold your hands in front of the exhaust pipes. If the flow is even, with no pauses, no shoting, the engine runs with all cylinders. ( warm engine ) Also if one of your pluggwires is not on the correct place, you will certainly hear it, just try. |
Rob Lay (Rob328gts)
Board Administrator
Username: Rob328gts
Post Number: 1344
Registered: 12-2000
| | Posted on Wednesday, March 27, 2002 - 9:51 pm: | |
Wow, I guess it's harder to know than I thought. I didn't take the plugs out, I just took the leads off and want to make sure I put them back on right. They clicked down nice. |
Jack (Gilles27)
Junior Member
Username: Gilles27
Post Number: 64
Registered: 3-2002
| | Posted on Wednesday, March 27, 2002 - 9:15 pm: | |
Bret,
You commendably list GV as one of your favorite drivers. His photo you see on my profile is one I took at my first Grand Prix, the '82 Long Beach race. For years I thought the negs were long gone, until they turned up last year! He will always be my favorite. Your girl isn't too shabby, though. |
Kelly J. Vince (Tifosi1)
Junior Member
Username: Tifosi1
Post Number: 175
Registered: 2-2002
| | Posted on Wednesday, March 27, 2002 - 8:26 pm: | |
Rob take the plugs out. The one that is wet is the one not running |
BretM (Bretm)
Intermediate Member
Username: Bretm
Post Number: 2070
Registered: 2-2001
| | Posted on Wednesday, March 27, 2002 - 6:29 pm: | |
It's a little harder to tell I think with a V engine. With an inline 6 I know that when a cylinder is missing it runs like a dump truck, idling rough etc. I would think there would be a slight loss of power, the quickest way to check if it's getting spark is to pull the wire and check it against the frame. |
Rob Lay (Rob328gts)
Board Administrator
Username: Rob328gts
Post Number: 1343
Registered: 12-2000
| | Posted on Wednesday, March 27, 2002 - 5:59 pm: | |
After disconnecting the plug wires to clean them, I wondered putting them back on how I could tell if I reinstalled them right.
What would be the symptoms of a cylinder not getting spark? Would it be obvious by the sound? Would it not be too obvious by sound or feel?
The car sounded and drove as it usually does today. |