DOA

[Odoyle]

+1 to Narfire's assessment. Definitely check under the hood where the clutch cable is passing through firewall and inspect thoroughly for cracks. There is a toroid (doughnut shaped) plate spot welded to the firewall where the cable passes through, around this are will be the damage if there is any. The primary cause for this happening is because of a poor ground connection between the motor to chassis, causing the electrical system to ground through clutch cable, heating the cable to point where it begins to bind. I was having similar issues as the ones you described in my 77 and it was a cracked firewall. Inspect and report back.

[Sscottdvm]

Thanks. I won't be back to my house until Friday but will check. I've looked from where it attaches to the pedal and passes through the firewall from the inside. Looks ok. Really hope it's not cracked

[phaetn]

I concur with others:

i) That 38mm oil wrench at Amazon is a God-send. You can't fit anything close to a regular socket in there without pulling the rad otherwise on my '74 1.8. Mine is a 3/8" drive so the wrench is narrow, too.

ii) Install a ground strap from engine block to firewall/chasis. This will prevent the clutch acting as a ground and prematurely failing.

iii) Something else to consider: If your firewall is okay, as others mentioned, then check the clutch pedal since it has a fork at the top which is where the end of the clutch cable fits in and it is actuated. These forks can sometimes bend/misalign and cause the clutch cable to shift. Check if yours is okay. If it's not either it needs to get welded or you need a new pedal. It is VERY unusual that the cable just "slip" one inch of travel and then you just readjust and it's fine. Something moved and isn't right.

iv) Get a new mechanic. Someone who says the car is "old" and shouldn't go over 60mph or 3,000 isn't worth having work on your car. That's a cop-out. If properly tuned these cars are great, though they always need some upkeep and dollars thrown at them. Safety first: Start with tires and brakes, then steering linkages and bearings, then worry about engine. Also check for rust around shock towers to ensure something isn't about to collapse. I've had mine up to 100mph on a number of occasions, though I don't do it regularly and I know it inside and out and only do it when I know everything is in really good working order. I routinely hit 80+mph and have driven on long trips of 500 miles plus where it was cruising at 4200rpm for literally hours. I wind my car over 5500rpm daily on my drive to work. It's a (somewhat) dependable daily driver, but I also work on it a lot so know what to look/listen for.

Good luck! I'm glad the fuel filter sorted out the hesitation!

Cheers,
phaetn

[Sscottdvm]

I agree, there's no reason that the clutch pedal should all of a sudden go to the floor then simply taking up the slack will fix it. Hate to look for problems but better than it snapping next time I'm driving.

The car is fairly solid otherwise. Minimal rust, brakes a bit soft but otherwise ok. It was very smooth for the 30 seconds I had it at 80mph. Need to drive about 15 miles to find a highway to cruise at high speed for a bit.

[nelsonj]

That's great news about the car running correctly. I use a cheap plastic see-through fuel filter because I like to monitor its condition and see if there fuel up to the carb. I'm not sure I have a check valve anymore though....

I wouldn't do any long drives until I have that clutch figured out per the earlier comments. Remember the two most important tools for a FIAT owners are 1) a cell phone, and 2) AAA card. Don't leave home without them.

Good luck - my stats show I have, on average, something that needs sorted out (read repaired) about every 2,000 miles on average. Usually something small...

[phaetn]

I spend a lot of time wrenching because it's a hobby. The "aftermarket improvements" I have made probably add a bunch of time to upkeep. Something that should be an easy modification ends up being complicated because it doesn't quite fit or affects something else.

If you keep it stock, it tends to just run well. Also, some components were just better made 40 years ago then they are now. Like it for what it is.

I keep telling myself "if it ain't broke, don't fix it" but then keep ignoring myself.

I hope the Fiat gods aren't listening... off to a big car show this weekend and my ailing wife has agreed to come along for the first time and catch some vintage racing, too. Yay!!

Cheers,
phaetn

[Sscottdvm]

Removed the brake fluid reservoir and took a look at where the clutch cable enters the firewall. Collapsed about 1 inch. Looks like PO had spot welded the area, obviously didn’t hold. I’ll have to bring it somewhere where they can do something with this. Any ideas of the best way to repair. Does the welder have to fabricate some kind of patch. I’d like some advice before having some mechanic tell me he needs to pull the engine and put in a new firewall

[Sscottdvm]

ODOYLE. this seemed to be the exact problem you had. How did you repair it ?

[Odoyle]

This is what my firewall looked liked like, PO had also put a thick piece 90 deg angle iron in front of this try try and solve the issue lol definitely made it worse.


I drilled out the spot welds on the doughnut shaped plate first. This is one of those repairs where things get ugly before the get pretty.


I have a 79 parts car, so I cut out the section of the firewall that had an undamaged plate. If you do not have this luxury, you can most likely get away with using your original doughnut shaped plate.


Mock up with old plate, I used 18 gauge galvanized steel (which was stripped with muriatic acid before welding)


I cut out the undamaged doughnut plate from the 79 (which double skinned) and welded that to the 18 ga reinforcement plate. Then welded the whole piece over the damaged area, after I stitch welded the cracked sections inside the driver footwell area. Not perfect but had to get done, has good penetration and is way stronger than before.


Ground down the weld as best as possible and metal prepped the whole area. Definitely had some head scratching moments throughout the whole process. I did this repair at the beginning of summer when photobucket started blocking photos, so i had zero photos of examples to go off. Since this I have done quite a bit stitch welding to the front box section, framerails, door sills, interior crossmember (where the windshield bolts up too), seat frame rails (horizontal), rear panhard rod box section and a few more.

[Sscottdvm]

If only I had a spare Fiat around. That’s a job that was obviously done well. Unfortunately my budget isn’t going to allow for a full restoration of the engine bay. When I find someone around here that will attempt to fix my problem I’ll show him your pics so he can get an idea of what needs to be done. Thanks.

[Sscottdvm]

Well , got the car back. The mechanic welded a plate and fixed the firewall ( .$640) The clutch now seems to work properly. Finally took the car out on the highway. Drove between 75-80 mph for 20-30 miles, other than a slight burning odor which I’m trying to ignore it ran very smoothly.
One final annoyance. Every small bump in the road, the exhaust ( or something under the car ) makes a sharp slapping noise against the chassis.
Seemingly right under the driver seat. The mechanic thought the emergency brake was getting in the way but still thumps at every bump. Kind of scary at 75mph. I assume someone on this site knows exactly what’s making the noise. Any help would be appreciated

[RRoller123]

The sound coming from under the driver's seat is odd, the exhaust is usually the culprit, but it runs down under the passenger side. Maybe the sound is just transmitting over to the driver's side. If actually coming from under front driver's side, front suspension is likely. Lots to check there, cross member bolts, control arm bushings, tie rods, etc.

[nelsonj]

The smell of the occasional "burp" of hot oil and gasses venting from the crank is one of my favorite parts of the FIAT driving experience! It connects me to the reality of what is going on in all machinery, and you certainly won't get the same experience in a Toyota! It's a smell I only associate with drive the car and it always brings back fun driving and other car memories.

But make sure nothing is really burning - that never ends well.

Sound like the hot-start issue hasn't been a problem lately. Very good and drive safely.

[kmead]

In regards to the sound under the floor, I would look at the following:

Exhaust mount to the rear of the transmission
Rear transmission mount
Guibo, the rubber ring that transmits power and allows some elasticity in the driveline
Drive shaft bearing and mount to the body

All these are in the area of your drivers seat.