Runs better with lots of advance...

[WBPDX]

I've been fine tuning my 79 2L with 1800 manifold and EMPI 32/26 for quite a while... It has always run, but has never pulled away great (Example: slowly rolling in 2nd gear and flooring it; it would take forever for the car to catch up with the throttle.) I went way richer on the idle jets in the carb; up to 65/70, which was a great improvement.

I decided to check the timing again tonight. I've been running with it at 10\12 - But it has always been smoother and pulled away much better with advance in the 20-25 range. I dialed it up to 22 tonight and took it for a spin around the block, and it was a huge improvement. The car rips right through it's rev range with the advance dialed way up.

I'm sure the solution isn't to simply dial the advance up. Did I mess something up while doing the headgasket\timing belt\etc.? I checked everything against the marks multiple times, and confirmed using the piston travel. Again, the car starts instantly and very easily. It even will putt-putt around town all day long... but without the advance dialed up, it is a painfully slow vehicle...

[htchevyii]

Is the centrifical advance in the dist working correctly? If it was I'd expect you'd get pinging, if it's not working then more initial advance might make it run better. Is it hard to start or does it backfire thru the intake when starting? Dist rotor screws too long can keep the mechanical advance from working. If you have a timing light, you can rev the engine and see the timing mark move as the ign advances. Also possible that your timing marks are off?

[Newell33]

You know, I've been going through the very same thing with my '73 1600 engine. In looking at the specs I've seen anywhere from 8 -12 degrees listed for advance. If I try to set my timing here the car will barely run, and has no power. It certainly doesn't sound or act like 8-12 degrees in my experience. I actually set my timing in the 20 to 25 range at the crankshaft. The car doesn't detonate, sounds good, doesn't run hot, and the plugs look good. I have electronic ignition. The centrifugal advance works, as well as the vacuum advance. I unhooked the vacuum advance just to be safe. I'm not sure what's wrong, but it sounds like we're in the same boat. The previous owner told me he had the top end rebuilt recently. The car definitely sounds like it has higher duration camshafts installed. My car also has a nice header, and freeflow type exhaust. I've spent a couple of weeks changing jets, tuning, and adjusting when I have time. Keeping the timing in this range is the only way my car will run properly.

I'd like to hear some opinions on this as well, so hopefully someone can chime in with some insight.

Josh

[nibbes123]

I run the advance around 20 same as you guys ,my engine is a 2litre with 1.8 head 4-2-1 exhaust , 32/36 weber carb electronic ignition ,the vaccum is disconected at the dizzy,car runs great with lots of power only thing is when idling it misses
once and awhile.
Nick

[baltobernie]

Total advance for the Fiat TC is between thirty and forty degrees, depending upon model year, emissions, etc.



Trey's suggestions are spot-on; I would only add that it is difficult to determine total advance without a "dial back" timing light. These are hundreds of dollars from Snap On and other quality manufacturers, but I got one from HF http://www.harborfreight.com/timing-lig ... 40963.html for $30. Very poorly made and fragile, but for occasional use, it's just fine. I turned the dial to 35, pulled the trigger and revved the motor. At high RPMs, the zero notch on the timing cover aligned with the crankshaft stripe.

Chasing aftermarket carburetor settings on modified engines is difficult enough without having to contend with other issues. Get your cams and ingition in time, then you're only dealing with idle jets, main jets, air jets .... (and changing one affects all the others )

[124ADDHE]

I think that maybe youur springs are worn out so that when you set the timing @ idle, there is very little centrifugal advance left for the rest of the rpm range and that would explain why you need such a high initial advance to make the engine run right @ the torque peak and above.

any pinging @ high throttle/low rpm?

[WBPDX]

The advance is working; increasing throttle increases the advance smoothly, using a timing light. I've also tested all parts of the electronic ignition, and everything is within spec.

As I stated, it is not hard to start; it probably starts faster and easier than my 2011 Tacoma...

I don't think the timing marks are off, because as I stated, I confirmed everything using the piston at TDC. I can imagine that MAYBE I made a mistake, but I don't think it is likely.

Does not miss at idle unless the advance is set down in the 5 or 8 range.

I have that exact dial back timing light from Harbor Freight. The total advance on mine is way higher than 35 if starting from 20... I will double check the exact advance:rpm ratio.

No pinging ever, but I haven't driven it much with this much advance...

[WBPDX]

RESULTS! (Not fixed, but more info!)


I was checking the total advance, and with the vac connected (from distributor to carb,) when set at 20 idle (which is where the best idle is and previously mentioned improvement under load) it will go insanely high when reved - up to 50 or maybe more (got scared and didn't rev any higher.)

I dialed the advance back down to 15, and it would still go to 40+ when reved with the vac connected.

Disconnected vac, dialed things back down to 15 - Total advance became about 35 (and unlike with vac connected, the advance doesn't infinitely increase)

Testdrove, and decided while it was VERY different in feel, it seemed to be getting too much gas. I stepped the idle jets back to 65\60... Whole new car. Tried my highway on-ramp test, and it was the FIRST time I haven't been scared. Car is WAY more responsive.

Pulling away from the stop signs on my test route, I noticed it seemed to have tons more torque; so much so, I was finally sure my clutch has been slipping... I pulled over, put it in 4th gear with my VERY weak e-brake on, and tried to take off - Nothing happened except a huge cloud of smoke errupting from my transmission tunnel... I did the same test a week ago, and the car would just stall.

Thoughts? (Other than 'I need a new clutch for sure!') Should I just leave the vac advance disconnected? What is making it over-advance?

[manoa matt]

Ditch the Harbor Freight timing lights, dial back or not. They are inaccurate right out of the box, and the dial back function makes it worse. Get a real timing light, like a Craftsman from Sears. $50 and its spot on. Buying Chinese products increases the national debt, and eliminates more American manufacturing jobs, now when we need them the most. OK, rant over.

Without a dial back light you can use a protractor or print out a degree wheel and make marks on the crank pulley for the desired total advance.

Does your 1979 2L with 1800 manifold and 32/36 carb, have any other improvements? If your compression is still stock, I'd suspect that you are still too rich on the idle jets.

[WBPDX]

Ditch the Harbor Freight timing lights, dial back or not. They are inaccurate right out of the box, and the dial back function makes it worse. Get a real timing light, like a Craftsman from Sears. $50 and its spot on. Buying Chinese products increases the national debt, and eliminates more American manufacturing jobs, now when we need them the most. OK, rant over.

Without a dial back light you can use a protractor or print out a degree wheel and make marks on the crank pulley for the desired total advance.

Does your 1979 2L with 1800 manifold and 32/36 carb, have any other improvements? If your compression is still stock, I'd suspect that you are still too rich on the idle jets.

While your misguided opinions on macro economics and international trade are extremely relevant to this topic, I'd like to point out that the timing light you've suggested, is in fact, made in China.

For the record - compression is still stock, 4-2-1 header. It may very well still be too rich.

[manoa matt]

Don't be so sure:

http://www.flickr.com/photos/bigtimes_f ... hotostream
http://www.flickr.com/photos/bigtimes_f ... otostream/

I like my tools to work correctly and accurately (especially timing advance). Keep buying that HF crap if it makes your wallet happy, it won't take away my job.

50/55 idle jets would be about right.

[WBPDX]

The dial-back models available from Sears, at this point in time, are made in china. I did not look at the standard models.

One of the models sold by Sears is exactly the same as the harbor freight version, just with a different sticker on the side.

Not that any of this is relevant.

I'll be playing with the jetting again today, and I'll put the timing gun on my truck to confirm it is accurate.

[manoa matt]

"One of the models sold by Sears is exactly the same as the harbor freight version, just with a different sticker on the side. "

Kind of like a MSD ignition control box: http://www.guy-croft.com/viewtopic.php?f=10&t=2630

[lanciahf]

Sounds like one of your cams are mis-timed and the extra timing is compensating for the mistiming. I had a similar experience.

"misguided opinions on macro economics " you are right i think this global economy is working well for the US, well at least for Wall Street and they love to share.

[opus10583]

Buying Chinese products increases the national debt, and eliminates more American manufacturing jobs, now when we need them the most. OK, rant over.

Point of order:

The current US National Debt is manifestly the result of structural deficit spending policies instituted and nurtured under the so-called conservative Reagan and several Bush administrations: Buying Chinese products helps fund those obligations.

Chinese manufacturing has largely replaced Japanese and Korean manufacturing of US-market consumer goods; Mexico and Canada are where "American" manufacturing jobs have been relocated to.

That said, buying Chinese products supports a completely corrupt and belligerent totalitarian state that engages in the violent suppression of dissent, promotes and protects abusive child labor practices, enjoys slave labor under the guise of political rehabilitation, and displays a contempt for environmental and aquacultural concerns that startles even the Japanese.