| Author |
Message |
'75 308 GT4 (Peter)
Intermediate Member
Username: Peter
Post Number: 2093
Registered: 12-2000
| | Posted on Saturday, October 19, 2002 - 11:45 pm: | |
Popping on decel. and shifting are at points when the throttle is closed and thus highest vacuum in the intake. Check for air leaks around the throttle shafts and carb bases (happened to me not long ago). This extra air is what leans the mixture out. |
Paul Newman (Newman)
Member
Username: Newman
Post Number: 603
Registered: 12-2001
| | Posted on Saturday, October 19, 2002 - 8:01 pm: | |
I had a slight popping on decel and found richening the idle mixture screws got rid of it. The popping is most likely lean mixtures but ignition timing being too far advanced will also do this. This can be base timing or stuck advance weights. Checking with a timing light will tell you both timing functions are right or wrong. |
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 268
Registered: 5-2001
| | Posted on Saturday, October 19, 2002 - 7:43 pm: | |
I had the crane cams XR700 system in my 78 308 and gapped at .034. No popping, in fact I did get some popping (miss) and it was because the mechanic inadvertently set the gap at .025.
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Sean Higgins (Sean_higgins)
New member
Username: Sean_higgins
Post Number: 13
Registered: 9-2002
| | Posted on Saturday, October 19, 2002 - 5:31 pm: | |
I changed all the spark plugs and gapped them to the correct gap, seeming the old ones were at .044 and the new ones are gapped at .026. The popping went away on acceleration, but now it still pops just a bit on deceleration or when shifting. Nothing super loud, but more like a tiny backfire. Does this mean the mixture could be too rich or too lean? Thans for everyone's help, this message board has been awesome with everyone putting in suggestions and a helping had to all that use it. I'm glad I found it a few months ago!! |