[jcgoodlett2]

most likely another noob question, but after reading through the owners manual for a 81 spider, I took note on page 15 in the bottom right of the page, a warning about NEVER shifting into 5th unless the engine temp is above 175 degree Farenheit...can anyone shed light on why this is?

 

[alfabeach]

most likely another noob question, but after reading through the owners manual for a 81 spider, I took note on page 15 in the bottom right of the page, a warning about NEVER shifting into 5th unless the engine temp is above 175 degree Farenheit...can anyone shed light on why this is?

All my manual says is "Do not drive at high speed until the oil in the engine, transmission and differential has warmed up properly" I take it easy until the engine is warmed up, but go into 5th all the time cold. Of course cold in Florida is fifty.

 

[Erik]

That is certainly not written in the manuals of any of the Alfas I owned.
They have generally advised not drive the car hard until it toughly warm. This means to rev it too high (over 3000 RPM) or pressure it at low rev (below 2000 RPM).
As I remember, the general speed limit in the US then was 55 MPH; the advice might have been given, as Alfa considered 5th gear to be to high for a cold engine and transmission to pull.
Erik

 

[Zunige]

... a warning about NEVER shifting into 5th unless the engine temp is above 175 degree Farenheit...

If I take out my 1974 Spider (it's SPICA, just like jcgoodlett2's 1981) when it's cold (something like 20 degrees Fahrenheit), and shift into 5th gear when the engine is not fully warmed-up, it will turn off. Yes, it will quit running! The first time it happened, I was leaving work. I warmed the car some in the garage, but not fully, drove for about a 1/2 mile, and then got on the interstate. I brought her up to highway speed and as soon as I shifted into 5th, the car turned off. It would start and idle fine, but as soon as I would start going into a high speed, it would turn off. Once fully warmed-up, there was no issue. I did this twice, and since then I have never tempted fate and have always warmed-up the car fully.

I don't know if my 1974 manual has the same warning as jcgoodlett2's manual, but I will check it and report back. I won't be able to check until the first weekend in December, but I won't forget.

Best regards,

 

[Giovanni2000]

My 1982 manual backs up what jcgoodlett2's 1981 manual states. Now as for the "Auto-Off" function that Enrique talks about, that part has yet to be witnessed...Thank God!!!

 

[Zunige]

...Now as for the "Auto-Off" function that Enrique talks about, that part has yet to be witnessed...Thank God!!!

Yeah, you are much better off without that experience! I have to confess that after the first time it happened, I tried it a second time on a different but still cold day, just to make sure ... (Yes, I was much younger back then, and a bit impatient...) After that second "assurance" I surmised that it was akin to a car running cold. When you shift into 5th (overdrive), the fuel mixture leans out (as it should) and the RPMs drop. When a car is cold, the cold sensor kicks in and more fuel is pumped into the engine, and the RPMs go up until it warms-up. Hence, I've always thought that running a cold car in 5th was similar to trying to run a cold engine without the cold sensor, and hence without enough fuel to keep the RPMs up. The cold car will not run well without the extra shot of fuel and it will turn off, just like my cold Spider did when going into 5th...

I don't know why Alfa put that warning in the '81/'82 manuals, but obviously running an engine lean, or leaner than it should, can cause it to detonate, and that's one thing you don't want to do. If I had to guess, that's what I would say is why the manual says "never", as in "never run your engine lean"...

Best regards,

 

[jcgoodlett2]

When you shift into 5th (overdrive), the fuel mixture leans out (as it should) and the RPMs drop.

now that makes sense, for when it is cold with lean mixture you may not get the burn in total causing the shutoff...!...

 

[papajam]

...a warning about NEVER shifting into 5th unless the engine temp is above 175 degree Farenheit...can anyone shed light on why this is?

I concur with others on this. Excessive engine wear can occur if under heavy load when cold. I think Alfa is simply stating that the oils be fully warmed up before exercising the full potential of the vehicle.

If I take out my 1974 Spider (it's SPICA, just like jcgoodlett2's 1981) when it's cold (something like 20 degrees Fahrenheit), and shift into 5th gear when the engine is not fully warmed-up, it will turn off. Yes, it will quit running!

I'd be most interested in learning more about this. I can not find anything in any Alfa document I have that mentions or shows a connection between the trans and the Spica pump (or ignition) for any Spica equipped year.
OTOH, maybe we should get together and fix it, eh?

 

[Zunige]

...
I'd be most interested in learning more about this. I can not find anything in any Alfa document I have that mentions or shows a connection between the trans and the Spica pump (or ignition) for any Spica equipped year.
OTOH, maybe we should get together and fix it, eh?

I don't really think there is an actual connection, such as something that detects that when the car goes into 5th, the SPICA leans out the gas supply. Of course, I'm guessing, but I just think that when you go into 5th causing the RPMs to drop as a result of the gearing ratio, the fuel supply leans out by how the SPICA is set-up... Anyway, you are more than welcome to observe this first hand. The only problem is that the car is in OH, and while I will be driving out there this week (Wednesday), I'll be flying back (and I will be at the NJ AROC dinner! ). Of course, I'm sure another trip will be planned for some time in Feb, and you are certainly welcome to join me. And yes, I'd love to understand what's going on and fix it!

Best regards,