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Discussion Starter #1
I started going throught the AROO Spica tuning procedure and ran into a snag right out of the box...

With a hot engine-
The gap at the lever was considerably more than .019" (actually about 1/4"). The instructions say that the screw under the TA should be set to a depth of 27mm (1973). If I adjust the screw to that depth, the gap at the lever is about 1/8", still a long way from .019".

Which way shold I go? Should I ignore the 27mm depth and back the screw out to get the .019" gap at the lever, or go for the 27mm depth and ignore the .019" spec?

I suppose the 3rd option is that I am missing something in this procedure.

Thanks in advance.
 

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What is the extension of your TA at 175F coolant temperature? Sounds like you might have a bad TA.

First off, I see that yours is a '73 model 1750. If still stock, the "T" number on the pump's dataplate should be "T255." Take a look at yours and make sure that it hasn't been swapped out sometime in the past for a later model. This is important because is affects the adjustment.

Assuming that it IS a T255:

1. There are 3 different types of TAs. A 27mm extension, 29mm, and 31mm. The 27mm model TA goes with a T255 pump. Later 70s models had 29 and 31mm models. Just about all the rebuilt TAs remaining are 29mm & 31mm models now. It's likely that your TA has been replaced in the past and is a 29 or 31mm model. If that's the case, then you need to put a 2mm or 4mm spacer under the TA to restore the hot extension back to 27mm.

You need to measure the extension of your TA to find out which one is installed. Heat the engine up to 175F and measure from the bottom of the flange to the tip of the piston on the lower part of the TA. It must be done at 175F. As the TA's age they may lose a slight bit of extension, which is no big deal . . . you can compensate for it with the adjustment screw in the pump body. If the TA is really going bad, the piston won't extend enough and that will cause a wide pump gap.

2. Let's say for the sake of argument that you find out you have a 29mm TA and a T255 pump. You measure the extension and it tests good at 29mm. Get a 2mm washer and put it under the flange of the TA. You might have to grind two sides a bit to clear the mounting screws. With the coolant at 175F, adjust the screw to maintain a .019" pump gap when the TA is installed. Don't let the temp vary from 175F while you do this or the TA extension will change on you. If your TA is a little weak in the extension (1-2mm), that's ok for now. Just adjust the screw to get the .019" pump gap.
 

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Discussion Starter #3
John-
Talk about instant gratification!
My car is a '73 GTV 2000, if that changes the pump #.
I understand what you're saying re shimming the TA, and will go after it tomorrow.
Thanks!
 

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Discussion Starter #4 (Edited)
Just checked, my pump is a T255, so next I have to measure the TA extension at 175F. What's the best way to do that, as it will start cooling as soon as I remove it from the pump-hot water?
Actually I just realised that I can measure the extension without removing the bulb!
Thanks!
 

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Discussion Starter #5
I just finished doing a test of my TA and it's shot for sure-it only extends 23mm when the bulb is immersed in boiling water-not enough to lean the mixture when the engine is hot. One of my AROC pals in Tulsa has a Shankle Sure Start that he's offering to give me. Since I'm chronically broke it may be the best option.
Thanks!
 

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Get yourself a "Dummy TA"

They're available (by year) to assist this adjustment. When I used to have a TA go bad (under warranty) I'd go through all the "Factory Settings," BUT once a client was "out of warranty" I'd recommend any client (with a hard starting problem) to replace the TA with a "Manual TA!" If your mechanic knew what to do; first remove the TA, then (make an open-end wrench to adjust the Barometric Compensator), loosen the BC with the engine warmed up, then get a 2' piece of wire (I know what's this for?), but crimp a female spade connector on, and now disconnect the "Positive Lead" from the BC, connect the wire you made, and find the "+Positive Junction Box" so you can "Hotwire" the BC. This forces the pump into a position it takes only during "Cranking a cold engine," adjust the BC clockwise or counter clockwise until the engine is running rich with wire connected. Once you've found that point disconnect the wire, lock the nut below the BC (all experienced Alfa Tech's have made one of these at some time), and then your ready to accurately adjust the TA, but for the TA to work correctly it must have the pin extend "x" when hot, and retract to "y" when cold (these lengths are different by year); so it was then that I'd just get the "Manual TA," (which is a glorified choke cable) to allow my clients "Easy Starting." I knew the "Midwest Service Rep," and he even had it on his own car rather than screw with it... I'll try to get the part number for the group because it was even back then a "Non-Factory Fix." But it worked!

Later,
Hank
 

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Get yourself a "Dummy TA"

They're available (by year) to assist this adjustment. When I used to have a TA go bad (under warranty) I'd go through all the "Factory Settings," BUT once a client was "out of warranty" I'd recommend any client (with a hard starting problem) to replace the TA with a "Manual TA!" If your mechanic knew what to do; first remove the TA, then (make an open-end wrench to adjust the Barometric Compensator), loosen the BC with the engine warmed up, then get a 2' piece of wire (I know what's this for?), but crimp a female spade connector on, and now disconnect the "Positive Lead" from the BC, connect the wire you made, and find the "+Positive Junction Box" so you can "Hotwire" the BC. This forces the pump into a position it takes only during "Cranking a cold engine," adjust the BC clockwise or counter clockwise until the engine is running rich with wire connected. Once you've found that point disconnect the wire, lock the nut below the BC (all experienced Alfa Tech's have made one of these at some time), and then your ready to accurately adjust the TA, but for the TA to work correctly it must have the pin extend "x" when hot, and retract to "y" when cold (these lengths are different by year); so it was then that I'd just get the "Manual TA," (which is a glorified choke cable) to allow my clients "Easy Starting." I knew the "Midwest Service Rep," and he even had it on his own car rather than screw with it... I'll try to get the part number for the group because it was even back then a "Non-Factory Fix." But it worked!

Later,
Hank
 

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A couple of observations on the above:

I think Hank is referring to the Cold Start Solenoid (CSS) and not the Barometric Compensator (BC). The BC is not electrically operated. Only mechanical via ambient air pressure.

I have never heard of this procedure and personally would not recommend it. The real fix is a rebuilt Thermostatic Actuator or mechanical Shankle Sure-Start (if you can find one). While waiting for one, it's easy to make a "dummy T/A" out of a bolt, a washer, and two nuts. Simply set the dummy T/A to 27 or 29mm (whichever is the spec for your pump. As long as the ambient temperature is not cold, the engine will probably start, albeit harder.
 

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Although others put them down, I've had good luck with the Sure Start in my '81. Works just like a regular choke. AR Ricambi advertises them in Alfa Owner magazine for 75 bucks. 800-225-2532. Their web site doesn't work.
 

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Discussion Starter #11
I have searched for the Sure Start installation instructions to no avail. Does anyone have them? Cable routing, etc.
Thanks. [email protected]
 

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71 Berlina 74 GTV 17 Giulia Q4
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Some of the best money I've spent on my Alfas is a rebuilt TA from Wes. He also did my pump, the HP, to match what I told him I'd done to the motor. The car bangs off even when it was in the 20's which is cold for here. I did put a push button on the CSS and now it's just a habit on the first cold start of the day to push it and crank. It starts so much eaiser now when hot, a bump of the key, now that it's not getting that extra shot of fuel it doesn't need.
 

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Discussion Starter #15
I'm going with the rebuilt TA as we speak. I'm shimming it a bit. The Rolex race is slowing me down!
 

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Discussion Starter #16 (Edited)
I'm getting really close...
Got the TA gap at .018" @ 175ish. Goes down to .013 right after a fast run (full hot). That's as good as I can get it. 1/2 additional turn on the long rod gives me too much gap, like .026.

I kept getting sputtering and backfiring from #3 and #4 when I cracked the throttle and when letting off from 2.5 grand or so. Throttle was very sluggish too. I had done the .002 shim adjustment on the throttle flaps but blocking the idle air valve did not affect the idle. When I blocked #4 with my hand I could feel light suction. Same on #3. Both of the fronts were fine. I adjusted the throttle screw until I had no suction. Now, the engine slows big time when I block the idle air valve. I'm sure wear on the throttle bodies made the shim adjustment technique irrelevant. It's a pretty old car.

I am going to advance the timing a tiny, tiny bit to raise the idle to 800 RPM. I plan to adjust the mixture by reading the plugs, which don't look too bad with the current settings.

Tomorrow morning will be freezing cold here, but the car is in the garage at 60F so I should be able to see how the cold starting goes. I'm doing all of this with my lever set at N. If all checks out I'll leave the car outsids and see how it starts below freezing with the lever set at C.
Thanks!
 

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Incorrect .019" adjustment ?

I'm getting really close...
Got the TA gap at .018" @ 175ish. Goes down to .013 right after a fast run (full hot). That's as good as I can get it. 1/2 additional turn on the long rod gives me too much gap, like .026.
I read that you did have the gap adjusted correctly before you started messing with the long rod.
The .019" adjust is done with the TA at about 175deg, or with a dummy TA set to 27mm like us cheap people do. The gap is only changed by turning the screw that is under the TA, ie, the TA pushes on that screw when hot.
Reading my Wes FI manual he says that when the car gets real hot,>175, the TA can extend more and will decrease the .019" gap almost to 0.
You do not adjust any gap by changing the long rod length. The long rod length is adjusted so that, after the .019" gap is achieved, it will just slide back in place without moving anything else.
 

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Discussion Starter #18 (Edited)
Paul-
I didn't adjust the rod length, all I did was check the adjustment parameters, and put it back. The long rod length adjustment is a part of the AROO procedure.
Thanks!
 

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With the long rod disconnected, the pump gap should be .019" at 175F. As the engine fully heats, the TA will continue to extend and drive the gap towards, or to, zero. That's normal.

Once that is set, reconnect the long rod and heat the engine up to normal running. Adjust the long rod to bring the pump gap back to .019." The reason for this is that .019" pump gap is where increased fuel delivery starts. If you don't adjust the long rod back to .019", then when you push on the accelerator pedal, the throttle arm on the rear of the injection pump has to move through that dead zone from zero to .019" before getting any increased fuel delivery.

Since your pump is designed for a 27mm extension TA, you need to shim a 29mm TA with a 2mm spacer (one ordinary washer), or a 31mm extension TA by 4mm (two ordinary washers). This will ensure that your cold start performance will be to spec.
 

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Discussion Starter #20
That's pretty much how it is now...it's snowing like crazy here so I'm not going for my (mixture) fine tuning test drive today.
Thanks!
 
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