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Discussion Starter #1
I am hoping someone out there has experienced the problem I describe below, and will be able to offer insight as to the cause. First, I have read many posts on cold start and start and die issues. My car, an '82 Spider Veloce always starts immediately and idles fine when just sitting (i.e., before getting underway). The car has 40,000 original miles though it did sit in its original owner's garage for about a decade. Last year, Julio my mechanic at Milano Motors in Kensington, MD did a tune up, valve adjustment, replaced all fluids, front wheel bearings, brakes, fuel pump, fuel filter, fuel pump relay, and new Interstate battery. Additionally, just before I purchased the car from the second owner, the gas tank and in-tank fuel pump was replaced. So generally the car runs fine.

Here is the problematic behavior it exhibits. Warm weather or cold the car fires right up and idles at about 950 rpm. Once underway, the car will run fine until about 20-30 minutes into the ride. At this juncture, at a stop light for example, the idle will become erratic and often the car will die. In every instance, after dying, it starts right up again. However, in some case upon restart the car will idle at 950 rpm, and in other cases the idle will be extremely erratic. Once underway the car, regardless of the restart idle condition (i.e., normal or erratic) the car may run fine for the next 20 minutes or so, or it may exhibit a drastic power loss where the car does not seem to be running on all cylinders and even with the accelerator almost fully depressed will not exceed 20 MPH, or so. In the later case, killing the engine and restarting on the fly sometimes cures the power loss problem. I have taken it back to Milano Motors where it never exhibits this behavior and all systems appear to check out. If anyone can help, I would really appreciate it.
 

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1966-2013
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This erratic idle after warmup, does it sorta rise to mabe 2000-ish RPM, then act like the fuel gets cut which causes it to drop to almost not running (or outright stall), then up again to the 2k range, then down, over and over?

If so, then you're AAV is hanging open.


Check the link in my sig for more infobits on the L-jet system and what to test/look for AFA troubleshooting and whatnot.
 

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Discussion Starter #3
Darren,

It does something very similar, though I do not believe the RPMs rise very much. I will note more carefully on the next test run. In any event, I will check out your link. Thank you very much for your assistance, and I will follow-up with posts on what I find (or not!).
 

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Discussion Starter #5
Elio, thank you. Pump and filter are about 200 miles old. However, I will check the grounds.

I did manage to test the AAV today. When unbolted, but still connected to its harness, I was surprised to hear a rattle inside. However, after a stint in the freezer, the inside opening remained partially opened in about the same position it was in when removed from the cold car. After bringing back to room temperature, I placed it in the warming drawer of my BOSCH(!) range. When removed, the opening was closed almost completely. So I guess it is functioning. Is the rattle when cold (and not attached to the cam cover) normal? Thanks!
 

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1966-2013
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No, the AAV shouldn't rattle.

***

You say pumps and filter are some 200 odd miles old.

How about the soft lines, any reason to think they may be internally faulty?
You get a flap of collapsed rubber inside there and you'll get simular failures (up to and including complete shutdown and some scary loss of power for no apparent reason while just cruising along)

This is even if the lines appear fine externally.

The only true way to check is to remove them and try to pull them straight with one end held up to a light while looking through the other to see if you can see all the way through. Barring that, running a bit of rod (coat hanger or the like) down through after they've been removed can also give you an idea if there's a partial clog going on. (don't try to rod them while still attached as it may jam whatever even more, or cram it into something you can't get it out of easily)

Blowing compressed air through is not a satisfactory alternate test compared to looking through or rodding.
 

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My guess is loss of fuel supply (at times)...
My first thought as well.
In addition to the above mentioned checks, a frozen closed fueltank vent check valve can cause a fuel loss. The fuelpumps are not designed to pull against a vacuum which can occur in the tank if the check valve is not allowing air into the tank to replace the fuel that is used.
 

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Discussion Starter #9
Have only managed to borrow a used AAV from the Alfa mechanic and replace the two old hoses leading to the AAV, check and clean the ECU ground (at the intake), check the flywheel sensors (they each read a tad over 1k ohm -- the Alfa mechanic was hinting that my problem may be the sensors). The result? Starts fine, runs for about 1-5 minutes, then dies. At least this is different behavior than before. If this means anything to anyone, clues are - again greatly appreciated. I will be going through the other checks above as time permits, and hopefully will soon epor tgood news.
 

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1966-2013
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Query:

How are the contacts at the AFM connection?

Look inside the plug and see if any of them are shoved back or loose and thus not making good (if any) contact with the blades on the AFM side of things.

Make sure the AFM flap moves freely too while you're at it, and if the plastic cover can be easily popped off the top of it, suspect tampering. (they don't come off easily unless someone has pried it off before)

Might be nothing, but worth looking into just the same.

Of course go through everything 4-5 times over checking for false air leaks too, including the short tubes that connect the plenum to the manifold.
 

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Discussion Starter #11
Unfortunately, work dictates that I go through all of the above suggestions slowly as time permits. In anticipation of doing further checks, I did remove the luggage platform and rear side carpeting to gain access to the ECUs, etc. I noticed that the altitude compensation device is missing. I went back to my Cardisc manual reproduction, and sure enough, as far as the manual's authors are concerned an '82 AR Spider is supposed to have a altitude compensation device. Since the car resides at - essentially - sea level I am not sure the device would ever be activated. However, could its absence effect the car's running condition? Thanks!
 
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