Random burst of Performance?

[4babycar]

Oh, I did check the centrifugal advance and it seems to move quite freely and the springs appear to be in good shape but don't offer a whole lot of resistance. Is this correct or should these springs be worn and in need of replacement?

[So Cal Mark]

I realize you said the throttle cable will be replaced, but using lithium grease is not a good idea. Dirt will stick to that grease and make the situation worse. Use a dry silicone or graphite lube
An electrical problem with the ign would most likely cause a misfire, not just reduced performance. Does your car still have a catalyst on it? 15 mpg is pretty low, you could have jetting that is not right or a restricted exhaust system

[4babycar]

Thanks for the tip on the cable, I will certainly keep that in mind for future reference. Regarding the exhaust it does still have at catalytic converter. The exhaust was updated by the PO to a 4-2-1, moved to the center of the car and with a ANSA dual tip muffler. How to I test the exhaust for a restriction? Also, is there any way to see if the jetting is in the ballpark? I am a complete novice when it comes to carbs so diagnosing or repairing them is challenging to me at this time.

[htchevyii]

If you have a timing light you can use it to make sure your dist is advancing properly. With the light hooked up rev the engine and you should see the timing advance.

[4babycar]

I guess I will have to beg, borrow, steal a timing light or the horror...... buy a new tool! That way I can check the timing, what should I look for in a decent timing light? Also, is there any way that I can test for the restricted exhaust? and finally, how to I tell if I have a jetting issue?

[rlux4]

I don't know who you have out there in the way of auto parts chains, but you can usually use one for free with a deposit that you get back when you return the tool.
If you end up buying one, my method of deciding how good a tool I need to invest in is to ask how often will it get used.
My timing light consequently is just a basic inductive type.
Ron

[So Cal Mark]

the neon type of timing lights are cheap-and useless. the bulb isn't bright enough to see anything. The better lights have a device to check the amount of advance.
As for the exhaust, have someone rev the engine while you hold your hand over the exhaust pipe tip (be sure to insulate your hand). If the catalyst is restricted the exhaust will be superheated and flow won't increase as the revs go up

[mdrburchette]

I like my Mac Tools timing light. You can check the advance with a turn of the knob....but like most good tools, it's a bit expensive. I'd rent or borrow one if you only have one Fiat.

[4babycar]

Well, it looks like I should buy a nice(r) light since I am the proud owner of 2 Fiats!

[mbouse]

DENISE!! Rent a tool that you could buy??

Wowzers, Mac tools are not cheap, 'eh? But, what self respecting Fiat owner would rent what can be bought for under $100?? Craftsman carries at least 8 different models, and only two of those are over $100.00.

i use my timing light at least once per year per vehicle, usually twice. first of the season, then again when it warms up. i cannot dream of operating a Spider without a timing light....and wouldn't do without one in my tool box.

[mdrburchette]

[quote="mbouse"]DENISE!! Rent a tool that you could buy??
But, what self respecting Fiat owner would rent what can be bought for under $100??
quote]

Well, Mikey, you know Fiat owners want to keep the cost of repairs down and that's why renting or borrowing is an option. Burchette rule of thumb: If you need to borrow it more than once, you need to buy it...and if you need to buy it, might as well buy quality.
Why do you check your timing twice a season? Does it go bad?

[racydave]

I purchaced a craftsman, its junk...

[mbouse]

Dave, i'm a cheap a22 Fiat owner, times two. I'll keep my junk Craftsman timing light. Denise's suggestion of Mac timing lights are quite pricy even for me.

Denise, big change in April weather and humidity compared to July here in "Winter Wonderland". Ask Dave about the change just between his front door and mine. No, the timing doesn't change.... but the vehicle's performance during those two periods sure does, especially when the engine is cold. checking to be sure i've got the optimum settings is nice to be able to do.

Besides... owning a timing light leads to use of a timing light.

[racydave]

Mine works sometimes, its agrivating as hell! But its the only one I have, cant justify spending the cash, and besides I control mine on the computer program now. I need a cheap lap-top.

[Jim DeShon]

I've had this happen a few times with various vehicles. I usually attribute it to just the right atmospheric conditions. Humidity makes a difference to fuel mix with carburators. It affects the air density. On F.I. engines this is compensated for by the MAF sensor. ...J.D.