greenacarina Posted December 31, 2008 Share Posted December 31, 2008 So, my SPFI wagon has this horrible hesitation under load....like almost undriveable. Can't find the info in any of my manuals on how the advance works (electronic, yes....but is there some vacuum sensor involved? how does it compensate for load?). Anywho, I was thinking of plopping in a distributor from an '85 that has the vacuum advance. Good idea? Bad idea? Should I be focusing my attention on something else? Thanks! Chris Link to comment Share on other sites More sharing options...
Skip Posted December 31, 2008 Share Posted December 31, 2008 I moved you post for better coverage The distributor in your SPFI car is a CAS - Crank Angle Sensor insides shown here The 85 has a more or less conventional electronic dist. completely different. Have you changed your fuel filter lately? Link to comment Share on other sites More sharing options...
kayakertom Posted December 31, 2008 Share Posted December 31, 2008 Another possibility is the air mass sensor located by your air filter. Link to comment Share on other sites More sharing options...
greenacarina Posted March 5, 2009 Author Share Posted March 5, 2009 OK, got out today in the currently tolerable weather and played with this thing some more. Tested every aspect of the FI system to rule that stuff out of the euqation. Air mass meter is within specs, fuel pressure is correct while running and sitting for 10 minutes (fuel filter is new), throttle switch is adjusted correctly. So, the symptoms that I am dealing with- car starts and idles fine, acceleration is a bit sluggish when rolling gently into the throttle. Falls flat on it's face and backfires under hard acceleration and under load. Ignition timing is set to factory spec and appears to advance when using a timing light in the driveway. I am still totally unclear how the timing advance is controlled (ECU???) and how load is sensed (normally manifold or ported vacuum on most cars, but apparently not this one). Any insight??? The ol' Haynes book is maginal at best. Chris Link to comment Share on other sites More sharing options...
greenacarina Posted March 5, 2009 Author Share Posted March 5, 2009 Sorry, should be "equation" and "marginal" ALSO- Is my notion of putting an earlier vacuum-advance distributor (from an '85) in my car ill-advised? Thanks. Chris OK, got out today in the currently tolerable weather and played with this thing some more. Tested every aspect of the FI system to rule that stuff out of the euqation. Air mass meter is within specs, fuel pressure is correct while running and sitting for 10 minutes (fuel filter is new), throttle switch is adjusted correctly. So, the symptoms that I am dealing with- car starts and idles fine, acceleration is a bit sluggish when rolling gently into the throttle. Falls flat on it's face and backfires under hard acceleration and under load. Ignition timing is set to factory spec and appears to advance when using a timing light in the driveway. I am still totally unclear how the timing advance is controlled (ECU???) and how load is sensed (normally manifold or ported vacuum on most cars, but apparently not this one). Any insight??? The ol' Haynes book is maginal at best. Chris Link to comment Share on other sites More sharing options...
naru Posted March 5, 2009 Share Posted March 5, 2009 Your other disty won`t work. ECU calculates required advance from TPS and airflow meter inputs. Suggest you measure fuel pressure under load when the problem occurs. Link to comment Share on other sites More sharing options...
greenacarina Posted March 6, 2009 Author Share Posted March 6, 2009 Your other disty won`t work. ECU calculates required advance from TPS and airflow meter inputs. Suggest you measure fuel pressure under load when the problem occurs. OK, will give that a go. Thanks. Chris Link to comment Share on other sites More sharing options...
ThirdEyeHatch Posted March 6, 2009 Share Posted March 6, 2009 Maybe a clogged cat? Link to comment Share on other sites More sharing options...
RMVR53 Posted March 7, 2009 Share Posted March 7, 2009 Chris you should check out the thread --- EA82 looses all power ---. You just might find a similarity/solution to your situation Bill Link to comment Share on other sites More sharing options...
The Dude Abides Posted March 7, 2009 Share Posted March 7, 2009 What about vacume hoses fellas Link to comment Share on other sites More sharing options...
GeneralDisorder Posted March 7, 2009 Share Posted March 7, 2009 Probably a bad TPS. Check it through the sweep with a DMM - might have bad spots in it. GD Link to comment Share on other sites More sharing options...
greenacarina Posted March 13, 2009 Author Share Posted March 13, 2009 Problem solved!!! It was a crappy fuel pump. This was certainly a good exercise in getting familiar with the injection system, however. Now on to more mundane things- timing belts, oil pump seal, exhaust studs...the usual suspects! Chris Link to comment Share on other sites More sharing options...
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