1979-1993 & 94 Conv [Subscribe to Daily Digest] |
this would explain your single cylinder missing for a while.. ??.. but your car is the same as mine i think.. just the basic CIS system no electronics..
if u bridge the fuel pump relay.. this gets the pump going without the engine spinning.. pull the injectors then lift the airflap.. fuel should squirt out of all the injectors in equal amounts.. the flap lifts a piston in the fuel distributor that lets more or less fuel thru to the injectors depending on its ride-height.. this being governed by the air-flow going past it which in turn is governed by the throttle valve position..
this is all pretty simple really.. the more u lift the flap the more fuel gets to the injectors.. the piston works four tapered slots.. one for each injector.. the injectors are simply nozzles..
the main fuel (distributor) pressure works against a back pressure.. this back pressure is governed by the warm-up valve.. the main distributor pressure is governed by a pressure release valve in the distributor body.. this main pressure minus the back-pressure provided by the warm up valve is the actual working pressure that powers the fuel squirting out of the jets.. when cold the warm-up valve lessens the back pressure which has the affect of increasing the working pressure of the fuel being fed to the injectors which in turn richens the mixture to facilitate a richer cold start..
i would be wary of taking the main distributor apart unless u really have to.. i cant see any way that it could be responsible for your miss at start up.. its the kind of thing that either works or it dosnt and isnt adjustable.. however i think the basic back-pressure provided by the warm up valve is adjusable.. this would enable basic mixture adjustments to be made thru-out the engines rev range.. lowering the back-pressure would richen the mixture thru-out the entire range.. increasing it would have the opposite affect.. i think there is an adjuster screw in the warm up valve to enable adjustment.. i have yet to pull mine apart to see thow.. he he..
contrary to what most folks think.. the adjuster screw that works on the air valve flap.. only affects the mixure at idle not thru the entire range..
anyway i dont think your problem is the main fuel dsitributor.. but bridgeing the pump relay and lifting the flap is the way to test things.. nothing will come out of the injectors unless u lift the flap.. and the fuel pump needs to be running.. the injectors will not work off of the residual pressure in the system..
trog100
posted by 62.254....
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
![]() |
![]() |
![]() |
![]() |
![]() |