Timing issue - hard to start

[normark]

Alright, I have a somewhat strange timing, or something else, issue.

When I have 10 degrees BTDC static timing according to the timing light gun it runs absolutely great with no sign of pinking at high load and nicely looking plugs - but it's almost impossible to cold start. I have to crank nearly forever, and when it's about to start the engine almost stops entirely for a brief second and then it shudders and starts with the help of a little throttle. The idling is not perfect however. The RPM fluctuates somewhat and it misses or something once in a while.

When I put static timing at 0 it starts fine but it only runs alright, not as great as before. Idling OK.

It starts quite alright when the engine is hot in any of these settings though.

Where should I go from here?

It's a 1969 1438 and according to my Haynes manual it should be 10 BTDC.
It's not the original distributor. Now I have a cam mounted converted to electronic (Pertronix LR-1). I know that some people are quite reluctant towards electronic. But I would appreciate some advice whether this could be timing related, timing advance related?, or perhaps carb related?

I have considered that the crank timing mark might be off so I'm not getting the correct reading. But then why does it run so good at 10 TBDC?

[georgeramos]

Sounds a bit like my issue although i am experiencing pinking under load. I have been changing the cam timing slowly each n
Morning and i am currently at 15 to 16 degrees btdc and its running better with less backfire (im reluctant to say NO backfire until i rin it cold again) . The advice given to me was to change the timing and note the difference. Id recommend you start with the same as its easy and free.

Best of lick and please let us know what happens.

[normark]

Well, next step might be to actually confirm that the cams are in the right location.

I forgot to mention before - When I use the timing light I can see that the timing mark jumps around quite a lot. Most of the engine revolutions it's steady at 0 or 10 or whatever I want, but it can jump back and forth quite a bit

[normark]

Resolved:

Turns out this is no timing issue - it's a cold start issue. The butterfly valve for the automatic choke does not close. If I remove the air filter and close it manually then the car starts perfectly!

It's somehow a mystery that this issue started as soon as I swapped dizzy...

[toplessexpat]

Best of lick and please let us know what happens.

That's certainly a novel approach. Although don't let your significant other catch you getting that intimate with what is, at best, an inanimate object...

... but I digress. If the crank mark is in doubt, check it, that's going to stuff your timing efforts. FWIW, I run at 10 degrees just fine, with Mark's Computronix dizzy-less ignition which gives me about 35/36 degrees of total advance.

... oh and check your timing light isn't doing something "interesting". Some of the fancy ones get all upset when you're using a modified ignition.

[bradartigue]

I have considered that the crank timing mark might be off so I'm not getting the correct reading. But then why does it run so good at 10 TBDC?

Tune it by ear. Simply turn the distributor until you achieve the highest point of smooth operation in between 0 and 10. Set the idle back to 850 and repeat. Make sure the carburetor idle speed linkages are set correctly (can cause poor cold starts if not). Throw the Haynes manual away and get a FIAT shop manual for your model year; the Haynes books have some errors and dumb procedures in them.

[majicwrench]

You guys need to read the OP's posts, he resolved the problem, it was not a timing issue.

Setting timing by ear is like target practice blindfolded. You might get lucky, but odds are you are gonna be way off.

[racydave]

There have been times in the past where I opted to set the ignition timing by the seat of my pants. And for various reasons. But I would like to think I am qualified to do so, being a life long professional tech, formerly fully ASE certified, and with the performance tuning test also. I would not suggest it on newer systems, but I would on our cars. The earlier days of achieving pollution standards left a lot to be desired. I control my ign timing completely thru my system, and it is one of the best improvements I have. I would suggest a good timing light with the advance feature. Know the total advance and then the base timing. Always check the vac advance, centrifugal advance, and bushings on the advance plate. If I ran my 79 spider on the stock set up, it would still be a dog. Just my qualified opinion. But I don't know everything, I'm still learning!

[bradartigue]

You guys need to read the OP's posts, he resolved the problem, it was not a timing issue.

Setting timing by ear is like target practice blindfolded. You might get lucky, but odds are you are gonna be way off.

Missed it. Thanks for the correction.

[toplessexpat]

Yeah ... me too... I was too busy being smart-arsed on "licking"