Attention: TDR Forum Junkies Last weekend I was out looking at my pump after reading in the archives about the Diaphram and start wheel and decided to do a little adjustment. Old School had great info about the Diaphram and how it works. His post said to turn it from 12:00 o'clock to 3:30, with 12:00 being at the top of the Diaphram by the valve cover.
Upon reading more and removing the diaphram, it is easy to see that the shaft is "tapered" and non concentric as you move down the shaft. Think of it as being shaped like a Dunce cap, but with one side or area of the cap being "shallower" than the other. I know this sounds totally ridiculous but you will need to have the wording out there with you when you are looking at it. Inside where this shaft sits is a pin that moves in and out as the throttle is engaged (you give it the gas). This pin is on the same plane as the crankshaft. With the diaphram out, move the throttle and the pin should come out. You can push it back in gently with a small screwdriver. Now realize that the diaphram shaft being tapered has a "shallow" side and a "deep" side ( I know it is not square but work with me here on this one). To get the most affect from moving the diaphram, turn it so that the shallow side of the shaft is pointing towards the pin that comes out as you engage the throttle. You want this pin to be able to move as much as possible to get the most fuel flow. I found mine to be set at almost the maximum "deep" side of the tapered shaft, thus limiting the pin movement to minimal travel and decreased fuel flow. I also turned the star wheel (which sits under the diaphram) clockwise one turn. I also, based on old schools writings, went two turns in on the smoke screw (located under the tamper proof metal cap). I get just a whisper of smoke on start up where as before I would get a nice little cloud whether the engine was hot or cold. I did not have time to test another half turn on the start wheel but will later.
Realize that my truck has the stock 21cm turbine housing, but boy did this little adjustment wake up the old ghost!!! It actually will break the tires loose from a dead stop with a little power brake. I have a 16cm housing sitting in the garage but not enough time to get it on (I know, I know excuses excuses). My PW injectors are also still in the box next to the Turbine housing ddddddooooooohhhhhhhhhhh!!!!!
I hope no one takes this explenation as an Algore talking down to you explenation, but until I found the info in the archives and printed it out and had it as reference while working all the explenations did not make sense to me. I'm not the sharpest knife in the drawer, but fairly lethal with good instructions!!!!! Hopes this helps.
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92 Ext. Cab, Auto trans. , 3. 54 Non-LS, Isspro Tach and Pyro (pre-turbo), 210,000+ miles, straight pipe,old and abused but still running strong!!!!
[This message has been edited by Shrimpy (edited 12-03-2000). ]
Upon reading more and removing the diaphram, it is easy to see that the shaft is "tapered" and non concentric as you move down the shaft. Think of it as being shaped like a Dunce cap, but with one side or area of the cap being "shallower" than the other. I know this sounds totally ridiculous but you will need to have the wording out there with you when you are looking at it. Inside where this shaft sits is a pin that moves in and out as the throttle is engaged (you give it the gas). This pin is on the same plane as the crankshaft. With the diaphram out, move the throttle and the pin should come out. You can push it back in gently with a small screwdriver. Now realize that the diaphram shaft being tapered has a "shallow" side and a "deep" side ( I know it is not square but work with me here on this one). To get the most affect from moving the diaphram, turn it so that the shallow side of the shaft is pointing towards the pin that comes out as you engage the throttle. You want this pin to be able to move as much as possible to get the most fuel flow. I found mine to be set at almost the maximum "deep" side of the tapered shaft, thus limiting the pin movement to minimal travel and decreased fuel flow. I also turned the star wheel (which sits under the diaphram) clockwise one turn. I also, based on old schools writings, went two turns in on the smoke screw (located under the tamper proof metal cap). I get just a whisper of smoke on start up where as before I would get a nice little cloud whether the engine was hot or cold. I did not have time to test another half turn on the start wheel but will later.
Realize that my truck has the stock 21cm turbine housing, but boy did this little adjustment wake up the old ghost!!! It actually will break the tires loose from a dead stop with a little power brake. I have a 16cm housing sitting in the garage but not enough time to get it on (I know, I know excuses excuses). My PW injectors are also still in the box next to the Turbine housing ddddddooooooohhhhhhhhhhh!!!!!
I hope no one takes this explenation as an Algore talking down to you explenation, but until I found the info in the archives and printed it out and had it as reference while working all the explenations did not make sense to me. I'm not the sharpest knife in the drawer, but fairly lethal with good instructions!!!!! Hopes this helps.
------------------
92 Ext. Cab, Auto trans. , 3. 54 Non-LS, Isspro Tach and Pyro (pre-turbo), 210,000+ miles, straight pipe,old and abused but still running strong!!!!
[This message has been edited by Shrimpy (edited 12-03-2000). ]
