924Board.org

russward · Joined: 07 Oct 2003 Posts: 44 Location: Germany

Can anyone let me know how to get the timing to the best setting for correct idle etc. What position should the air adjusting screw be to start - all the way in or out, where should throttle adjusting screw be positioned etc. What order do you make adjustments between dizzy, air intake and throttle adjustment.

Thanks

Russ

Lizard · Posted: Wed Feb 11, 2004 9:30 am Post subject:

ok here it goes, if the vehicle runs dont touch the air fuel mix,

first set the timing with a timing light, set to 6 deg BTDC,
next try to start if no then make sure the fuel pump comes on,

as per the air fuel mix though, here is what I found though,
jumper the fuel pump relay so it is always on, then turn the air fuel mix screw all the way lean, then turn to rich slowly, you will here a psshhhh this is the fuel leaving the fuel dizzy, then keep turning to rich till you hear another noise it will be more a ppppppssssshhhhhhhtttttttttttt this is the fuel escaping the injectors (another option is to pull the injector and watch the fuel begin to escape), then turn the screw to lean just until this sound stops, there done, now try to start the vehicle, however I warn again if you can get the vehicle running without touching this LEAVE IT ALONE, you will cause yourself a headache once you have this done then use the CO screw on the throttle body to set the idle time and voila,

it really isnt that easy though
_________________
3 928s,

John Brown · Joined: 07 Nov 2002 Posts: 903 Location: Leesburg VA

That procedure is along the same lines as that described in Haynes. However, the Haynes is probably a little more likely to keep excess fuel out of the cylinders as the visual indication of fuel is likely to be more easily and quickly seen.
_________________
John
80 931 - #931 44Cup
99 Escalade - tows track cars
gone but not forgotten: original 924.org car - 82

russward · Joined: 07 Oct 2003 Posts: 44 Location: Germany

Sorry guys, I didn't make myself clear - the car starts and runs ok - I believe the fuel air mixture is good, yet when accelerating it seems to bottom out or the engine gives nothing more than 4500 rpm in fourth or fifth gear - can't red line it even if I wanted to. I thought this was all to do with the setting of the Dizzy (distributer), the CO screw on the throttle body and the throttle cable adjusting screw.

Is this clearer - sorry if not

Russ

Lizard · Posted: Thu Feb 12, 2004 5:11 am Post subject:

first set the ign timing to 6 deg BTDC and try again.
_________________
3 928s,

Alex Roy · Posted: Thu Feb 12, 2004 11:05 am Post subject:

Check all your vacuum hoses. The timing is supposed to be advanced by the vacuum created by the engine as a function of rpm and throttle position. With the age of these cars, I'd just recomend replacing all vacuum lines with new lines anyway.

augidog · Joined: 03 Mar 2003 Posts: 1360 Location: New Jersey

Lizard · Posted: Thu Feb 12, 2004 2:45 pm Post subject:

I dont think so, That is what I set the 931 to and it was fine, I cant say what the 924 runs at I just do it by ear shall we say, also if you do a search I do believe that is what vaughan suggests too
_________________
3 928s,

924RACR · Posted: Thu Feb 12, 2004 11:48 pm Post subject:

Yeah, it runs pretty sweet around that mark.

The throttle cable should never be adjusted - it's set from the factory. Idle speed adjustment is a different screw on a boss in the front of the throttle body.

But that may not be your issue at all. If you're running out of steam - have you replaced the fuel filter recently? Almost sounds like the engine may be getting choked up (though I don't think you'll get it to redline it 5th gear, I don't recall these being rev-limited for top speed).
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype