Could it be the clutch?

[michaelgough]

Hi all. 1981 Spider has been running well, but all of the sudden it has seemed to lost some Punch. Lower gears at slow speeds seem pretty normal, but 4th and 5th seem odd - like the power is not getting to the wheels, especially going up hills. Is there a way to test the clutch without dropping the tranny?
Don't think this is relevant, but tach often bounces around above 3500, but I don't feel that the revs are bouncing around. Wrote it off to bad electrical connection.
Last thing - where can I get a speedo cable.
Thank you in advance

[18Fiatsandcounting]

Fuel injection, right? The FI systems are pretty good, so I suggest checking the ignition system in terms of the static timing, does the advance curve work as it should, etc. Bouncing of the tach needle can be a sign of a hiccup in the ignition, like missing.

I doubt there is anything wrong with the clutch. The classic symptom for that is to drive up a long hill in 4th or 5th gear, floor the gas pedal, and if the engine speed (tachometer) increases but the car speed (speedometer) does not, then you have a slipping clutch.

Speedometer cables are sold by the usual suspects: AutoRicambi, Midwest-Bayless, and Vick Auto. Make sure you get the right one for your model year as there are differences.

-Bryan

[michaelgough]

Thanks Bryan,
Fuel injected it is. I will execute the classic hill clutch test today. Tried this on a small hill previously, and the revs did increase, but not the speed. In fact that is where it felt like it was losing power. Once the road leveled out, it seemed to respond closer to normal.
I am not a great mechanic, but learning. Do I still check the timing with a timing light? Any other test for ignition problems? I am grateful for your insight.

[michaelgough]

Test results - not sure if it's the clutch
Drove the 81 this morning 8 miles into town and everything seemed normal. I was wondering if I had imagined things. Spent 15 minutes in the Hardware store, and when I started home the weirdness started again.

Took it to a hill for clutch test. Even on level ground in 3rd could barely get the revs above 3000. When I punched it, the pitch of the engine changed, but not the revs or speed of the car. Barely made it up the hill. Felt like the brake was on. Coasted down the hill to assure myself it wasn't a seized brake.

Driving home it was hard to get the rpms above 3000 in 4th or 5th. Again punched the accelerator - engine pitch changed but revs barely moved and no speed increase. For a moment I seemed to smell that Clutch/brake smell. When I pushed in the clutch, I could get the revs above 3500.

Puzzeled

[18Fiatsandcounting]

Even on level ground in 3rd could barely get the revs above 3000.

That's definitely not normal. It still doesn't sound like a clutch issue to me, but rather an engine that has a problem. A few possibilities:

1) Incorrect ignition timing, or the ignition advance mechanism is stuck.
2) Plugged fuel injectors or a bad fuel filter (either before or after) the fuel pump.
3) Plugged catalytic converter (if you have one) or a plugged exhaust system in general. It can happen.
4) Really worn out engine in need of a rebuild, but that doesn't sound like the case here.

-Bryan

[Nut124]

I'm confused by the reporting.

One post says that in a hill. when stepping on it, rpm increased but the speed did not. This would be a sure sign of a slipping clutch.

Later post state that one could not get the rpm to increase when trying in 3rd on level. Now, this would be sign of a dragging brake or poor engine power.

[Spider951]

From my limited experience with failure to get engine to rev above about 3000 rpm and lack of power (I had this problem about 6 mos ago), I would offer the following possibilities (start with cheapest first): 1. incorrect dynamic timing (check with timing light); 2. running rich (spark plugs heavily coated with carbon) - replace plugs and lean out setting on Air Flow Sensor (have to remove the lid to get to it - some folks frown on this, but it was easy); 3. clogged fuel injectors (kind of expensive to replace); 4. run non-ethanol gasoline (a significant difference maker in my case - possibly not an option in all places).

Your problem doesn't sound like a clutch issue to me (??).

[michaelgough]

A big thanks to you all for your insight. I apologize for the confusion on revs increasing. The pitch of the engine sound changed, but revs barely changed and speed of car had no change.

Pretty sure not a brake problem as it coasted down the hill freely.

Will follow the groups advice and start with timing, fuel filters, premium fuel and some Sea Foam injector cleaner.

Very grateful for this unselfish group. Gives me more confidence in figuring this out.

[18Fiatsandcounting]

Pretty sure not a brake problem as it coasted down the hill freely.

It doesn't sound like a brake issue, but the easiest way to check this is to feel all 4 wheels (the steel part), or the brake rotor/caliper if you can, after driving the car for a bit. They might be somewhat warm especially if you just stopped driving to check the temp, but they shouldn't be hot (let alone scorching hot).

-Bryan

[Spider951]

You mentioned maybe running premium gasoline. Premium contains the same amount of ethanol as regular (at least here in AL), so I doubt that will help (premium just has a higher octane rating to prevent knocking).
One of the things I noticed when cleaning out the fuel rail on my '81 FI system is that there was a decent amount of fine rust in the rail. Ethanol is known to "attract" water, hence the rust - the rust was possibly the cause of partially plugging the injectors. Even though the non-ethanol gas I now use in my car is lower octane, the engine runs considerably better. I noticed a difference the first time I even put half a tank of non-ethanol gas that mixed with the premium ethanol fuel that was already in the tank.