Backfiring

[blurple124]

Hi,

I just bought my spider and noticed that it will backfire sometimes when I let off the throttle at a mid-range rpm (between 4 and 6 grand). This didn't seem to happen when it was well warmed up, but perhaps it is just a coincidence that it didn't. I wouldn't know for sure because I have not driven it much yet.

Is this more likely to be a fuel system issue or a timing issue? I was thinking that perhaps the timing advance is out of tune (these do have timing advance, don't they?).

[DougC]

What year is your spider? Electronic ignition? FI? More details are needed...

[majicwrench]

Backfiring in the exhaust?? All engines came equiped with "stuff" to keep that under control, a lot of that "stuff" is removed by people. A certain amount of backfiring is not cause for concern, but you don't want to blow your exhaust apart. To backfire, you need air in the exhaust, usually from an exhaust leak.
Keith

[blurple124]

Oh, yea, sorry. It is a 1978 with a carburetor. a 1.8L I4.

[DougC]

Oh, yea, sorry. It is a 1978 with a carburetor. a 1.8L I4.

Could be ignition timing, but also check your point gap.

[blurple124]

Well after further inspection I decided that the dry-rotting in every single fuel and air hose in the engine had maybe, just MAYBE been the reason for the backfiring.....just a hunch. Needless to say, they have all been replaced.

Now if I can only get the starter motor to work, I can know for sure!!!

[124JOE]

is the key not working?

[blurple124]

Something very Italian is going on between the key and the starter solenoid....I'm not sure what yet. Investigation continues.

[124JOE]

IF ITS ALL BOLTED UP AND WIRED
then you may need a new ING they go bad as heat burnt and dirty contacts sometimes works sometimes dont
it gives power to the coil,starter,harness and other stuff

i would get a new one with key

[blurple124]

Well I'm going to run around with a DMM and see if I can't narrow down the problem that way.