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Re: Making my '74 a good daily driver
Posted: Tue Feb 15, 2022 10:18 pm
by 18Fiatsandcounting
FiatRunner wrote:The car always starts up with less than 5 or 6 seconds of cranking, unless it’s been sitting for upwards of two weeks or it’s very cold outside. Once it’s been warmed up, and sitting for less than an hour, all I have to do is bump the key.
That sounds like it's not getting enough fuel. Try pumping the gas pedal a few times, waiting a few seconds, pump some more, then try to start. 1970s spiders typically don't start right away under all conditions, unlike modern cars. It's part of their charm.
-Bryan
Re: Making my '74 a good daily driver
Posted: Tue Feb 15, 2022 10:58 pm
by Nut124
I'm with Bryan here.
A carbureted engine, when cold, i.e. not at running temp, needs some enrichment, encouragement to start -> choke.
In the absence of a functioning choke, one pumps the gas pedal a few times on a cold engine while cranking.
A hot engine is the opposite, floods easily and needs open throttle to dry out and start.
Re: Making my '74 a good daily driver
Posted: Tue Feb 15, 2022 11:03 pm
by FiatRunner
18Fiatsandcounting wrote:Try pumping the gas pedal a few times, waiting a few seconds, pump some more, then try to start.
This has always seemed to work for me.
My typical startup procedure involves 3 or 4 pumps of the gas pedal, and half choke. More pumps if it’s been sitting longer than a week.
If a lean condition was the case, how would I resolve it? Just some fatter idle jets?
I’m not sure if this means anything, but the car won’t run or start on full choke. I always put it about halfway, and if I ever get past 3/4, it starts to die.
Re: Making my '74 a good daily driver
Posted: Wed Feb 16, 2022 10:36 am
by 18Fiatsandcounting
FiatRunner wrote:If a lean condition was the case, how would I resolve it? Just some fatter idle jets?
I’m not sure if this means anything, but the car won’t run or start on full choke. I always put it about halfway, and if I ever get past 3/4, it starts to die.
Don't change the idle jets as that will mess up your (hot) idle. It sounds like your choke is not working quite right. There is a circuit called the "choke unloader" and it's almost always broken on these old carbs. Its function is to automatically pull open the choke plates slightly when the engine fires, so that the engine doesn't starve for air.
You could try pulling the choke all the way on and then immediately when the engine fires, push it in a bit so that it doesn't stumble. You essentially become the choke unloader.
But if it doesn't fire at all when the choke is fully on, there could be something else going on like a weak spark.
-Bryan
Re: Making my '74 a good daily driver
Posted: Wed Feb 16, 2022 11:41 am
by FiatRunner
18Fiatsandcounting wrote:You could try pulling the choke all the way on and then immediately when the engine fires, push it in a bit so that it doesn't stumble. You essentially become the choke unloader.
But if it doesn't fire at all when the choke is fully on, there could be something else going on like a weak spark.
Okay. I'll try this as soon as I can. At this point, I've gotten very good at managing the manual choke. If it makes any difference, the carb on the engine is a Weber DHS. I'd rather not mess with it too much, as it runs very well (once it's started), and in a couple years I'd like to try out a dual IDF conversion. If I can leave the carb alone for a couple years, that's great.
I honestly don't mind letting the engine crank for a few seconds, my car came with a amazing battery made by a company called AntiGravity Batteries. It's a lithium-ion battery that weighs about 1/4 the weight of a normal battery, and still delivers 600 cold cranking amps. (maybe more- I don't remember exactly) It has a backup power mode for when you accidentally leave the lights on, and it works with a normal alternator. Frankly, it's awesome, although I do believe they're quite expensive.
As for the weak spark, I wouldn't think that's the case. The car has a Pertronix electronic ignition, and I replaced the plugs and wires when I bought the car last fall. I grounded out one of the plugs and watched the spark as it cranked over, and it was a very bright blue spark. I've never had a spark-related issue.
Re: Making my '74 a good daily driver
Posted: Wed Feb 16, 2022 12:59 pm
by 18Fiatsandcounting
FiatRunner wrote:Okay. I'll try this as soon as I can. At this point, I've gotten very good at managing the manual choke.
That might be the trick. I've always had to play with the manual choke, accelerator pumping, and throttle position to get my (older) engines to start after sitting for days or weeks. The optimal method also depends a lot on ambient temperature. Zero degrees F takes a lot more work than 50 oF.
I also have a sneaking suspicion that gas is not as volatile as it was decades ago, for emissions reasons. Less volatility = less evaporation loss into the atmosphere but also harder to start. However, this is total conjecture on my part, and I can't point to any evidence. Perhaps not an issue for a modern car, but for a 4 or 5 decades-old carburetted Fiat, maybe the gas makes a difference?
-Bryan
Re: Making my '74 a good daily driver
Posted: Wed Feb 16, 2022 2:27 pm
by FiatRunner
18Fiatsandcounting wrote:I also have a sneaking suspicion that gas is not as volatile as it was decades ago, for emissions reasons. Less volatility = less evaporation loss into the atmosphere but also harder to start. However, this is total conjecture on my part, and I can't point to any evidence. Perhaps not an issue for a modern car, but for a 4 or 5 decades-old carburetted Fiat, maybe the gas makes a difference?
I haven't been around long enough to have an opinion on gas volatility vs. time, but when I raced go karts as a kid, it was always obvious who was running race gas and who wasn't. I also built racing engines in my spare time, and it was always interesting to see the tuning and power differences depending on what fuel you were running.
I also wonder how a modern go kart or dirtbike carburetor would compare to our Weber IDF's and ADF's. Many new dirtbikes come with carbs that have progressive jets and circuits, to more accurately dispense fuel and air. I think it would be interesting to see a side-by-side comparison.
Re: Making my '74 a good daily driver
Posted: Fri Mar 11, 2022 10:08 am
by FiatRunner
Couple of small updates.
I was able to get the car out and on the road last weekend, and it was great, but it's since snowed twice and the car probably wouldn't make it out of the driveway.
However, I did clean the 48 years of dirt and dust out of the trunk, and I'm getting a new tire for the spare wheel. The old one looked original and didn't hold air for more than a few hours. I'd like to paint the trunk with some sort of rust preventative paint or sealer. There isn't any rust, but the trunk is dirty and a mix of the original color and the poorly resprayed one, and it doesn't look good at all. Any product recommendations?
As soon as it's warm outside, I will be replacing all the steering links/joints. It needs it, badly. Speaking of the steering, I'd like a new, but stock steering wheel. Mine has multiple large cracks. More importantly, I was wondering about a spacer for the steering wheel. I am very long-legged and short-armed, and my knee hits the wheel when I try to heel-toe downshift. If I could space the wheel a couple inches further back, that would be amazing. Are there any vendors that sell a spacer?
I've also ordered many small items, including a coolant bleed tee, new emblems for the hood and trunk, new transmission oil and gasket, and battery hold down. I've been slowly cleaning all the car's nooks and crannies, and clearing out the engine bay .The little details make me the happiest!
Re: Making my '74 a good daily driver
Posted: Sat Mar 12, 2022 6:23 pm
by redcars
If you find spacers for the steering wheel please post as I have the same problem.
Re: Making my '74 a good daily driver
Posted: Sun Mar 13, 2022 11:21 am
by 18Fiatsandcounting
FiatRunner wrote:...I was wondering about a spacer for the steering wheel. I am very long-legged and short-armed, and my knee hits the wheel when I try to heel-toe downshift. If I could space the wheel a couple inches further back, that would be amazing. Are there any vendors that sell a spacer?
I'm curious about this spacer as well. One of the jokes about Fiat spiders when they first came out is that the driving position was built for orangutans: Longer arms and shorter legs. So, it's not you. The pedals are just too close and the steering wheel just too far away for most drivers. Except for the orangutans, of course.
-Bryan
Re: Making my '74 a good daily driver
Posted: Sun Mar 13, 2022 11:37 pm
by FiatRunner
18Fiatsandcounting wrote:
I'm curious about this spacer as well. One of the jokes about Fiat spiders when they first came out is that the driving position was built for orangutans: Longer arms and shorter legs. So, it's not you. The pedals are just too close and the steering wheel just too far away for most drivers. Except for the orangutans, of course.
Does the stock steering wheel use multiple small bolts or one big center nut on a splined shaft? I wonder if I could use one of the wheel adaptors/spacers that are available from some of the online vendors.
Something like this:
https://autoricambi.us/hub-adaptor-1972-85/
I guess that buying an aftermarket wheel would solve my issue, but I do like the look and feel of the stock one. I'm not totally opposed to buying an aftermarket wheel, but that would be another expense that could've been used for a more urgent or more important fix.
Re: Making my '74 a good daily driver
Posted: Mon Mar 14, 2022 12:07 am
by 18Fiatsandcounting
FiatRunner wrote:Does the stock steering wheel use multiple small bolts or one big center nut on a splined shaft?
Both, depending on model year. My recollection is that from '68 through '78, the steering wheel was attached via the center hub to the splined shaft of the steering column and held in place with a big center nut. From 1979 onward, there was again a splined hub held onto the steering column shaft with a nut, but the steering wheel bolted to this hub with 6 bolts with recessed Allen-head screws.
The challenge would be the turn signaling canceling mechanism and horn setup. Turn signals were one design from '68 through '72, and then a different design onward. The center horn button was one design up through '78 but then different after that.
What I would do is call AutoRicambi or the like and see if they have ever dealt with this modification before. Surely someone has extended the steering wheel to be closer to the driver. Maybe one of the vendors even sells a kit for this.
-Bryan
Re: Making my '74 a good daily driver
Posted: Mon Mar 14, 2022 9:46 am
by FiatRunner
18Fiatsandcounting wrote:The challenge would be the turn signaling canceling mechanism and horn setup. Turn signals were one design from '68 through '72, and then a different design onward. The center horn button was one design up through '78 but then different after that.
What I would do is call AutoRicambi or the like and see if they have ever dealt with this modification before. Surely someone has extended the steering wheel to be closer to the driver. Maybe one of the vendors even sells a kit for this.
This makes me wonder if I could move the entire steering column and wheel towards the driver. If it only requires a longer steering shaft, I would think that it would be possible, but this might pose other challenges such as the wiring being too short, or finding a way to mount the whole thing.
I'll call AutoRicambri and possibly Allison Automotive and ask if they've ever done something like this. I also agree, I can't be the first person to ever want a spaced steering wheel.
Re: Making my '74 a good daily driver
Posted: Mon Mar 14, 2022 11:23 am
by 18Fiatsandcounting
FiatRunner wrote:This makes me wonder if I could move the entire steering column and wheel towards the driver.
I think there's enough slack in the wiring to do this, but my concern would be modifying the geometry of the steering column universal joint so that it wouldn't collapse like it should in a frontal crash. You don't want your steering wheel to be your air bag...
I think extending the steering wheel hub will be your easiest option, but let us know what you find out.
-Bryan
Re: Making my '74 a good daily driver
Posted: Mon Mar 14, 2022 2:01 pm
by FiatRunner
18Fiatsandcounting wrote:I think there's enough slack in the wiring to do this, but my concern would be modifying the geometry of the steering column universal joint so that it wouldn't collapse like it should in a frontal crash. You don't want your steering wheel to be your air bag...
I think extending the steering wheel hub will be your easiest option, but let us know what you find out.
Changing the crash geometry definitely wouldn't be ideal. The car isn't exactly safe in the first place, and I'd rather not do anything to make it even less safe.
It makes me wonder if I could use a steering wheel that is slightly smaller in diameter, small enough to make room for my knees, but still big enough to provide the necessary leverage the manual steering requires.
Either way, I'll still be calling AutoRicambri and Allison after my classes today. I appreciate the imput!