Dwell angle at the Starting points on a 1978.

[lvacordian]

My FIAT takes a few tries to start when cold, and I’m wondering if incorrect dwell on the starting points is the culprit. This problem is especially pronounced in the fall and winter months. After setting both sets (starting and running) to 55 degree dwell, and doing all the tests outlined in the factory manual (pulling relays and connecting jumpers) I’m still having difficulty obtaining the 10 degrees of advance that should be occurring at the starting points.

The factory manual suggests that the dwell be adjusted (changing point gap) in order to obtain the 10 degrees advance, but if I do that then the dwell to be outside of the 55 degrees spec. It sounds to me like there is an underlying problem, except I don’t know where to start looking. My fuel delivery checks out fine. I’m about to get the car smog tested and so I’m trying to make this right.

Should the starting points have a different dwell angle than the running points on a California 78 spider and if so what is it?

[majicwrench]

I ahve no idea what the factory suggested dwell is, sounds like you have the book. But dwell does not have to be exactly 55, and changing it a few degrees will also change the timing. So I would do as the book suggests and vary the dwell/gap.
Keith

Oh, and I really doubt that the dwell etc is causing the slow start.

[lvacordian]

Thank you for your reply. I'm thinking that the dwell angle of starting points dwell is significant for starting because the factory manual says that they are used exclusively for starting: whether hot or cold. If the dwell angle isn't adjusted properly then wouldn't that have an effect on the engine firing immediately on the first try. This could especially be true because the starting points are supposed to give 10 degrees of advance, and the dwell angle is what creates that advance for the starting points. That 10 degrees is supposed to help with easier starting, is it not? The running points do not any advance, so it appears to me that the dwell angle and point gap should be different from the running points. I'm wondering if anyone knows what the dwell should be for the starting points because it's certainly not the 55 degrees that FIAT says it should be. That would be only for the running points, right?

[seabeelt]

It's a bugger to get just right. Supposed to be 53 +/- 2 for both sets if I recall correctly. You do need to pull to the relay that switches from starting to running points and jumper the correct set of points to measure while setting the timing, otherwise the dwell looks all wrong on the meter.
R/

[majicwrench]

No reason why they couldn't and shouldn't have the same dwell and gap. But by differing the gap (dwell) you can increase/decrease the difference in advance between the two sets.
Dwell is not one of those thing that you have to be spot on. Methinks you are overthinking it, and again, a few degrees of timing or dwell are not going to cause your hard starting.

[lvacordian]

Thanks so much for all your help. Perhaps I am over thinking this. Oh the joys of California state emissions testing. Oh the joys of California state emissions testing. Every smog tech I've ever talked to says these cars never pass. How are we supposed to keep these cars on California's roads when the standards are so high, and are actually beyond the cars originally designed emissions capabilities? Many emissions testing facilities don't even have the correct equipment to properly test these cars. I'm specifically talking about the gas cap adapters to test the fuel evaporation system, yet many still want to charge for the test even though they never administer it

[sptcoupe]

Just saw this thread. The dwell should be set at 55, +/- 2 degrees. The other way to set them is to use a feeler gauge and set them at .017" when the points are fully opened (on the top of the cam lobe). So clearly this is not a precise adjustment.