ihscout54 Posted March 7, 2009 Share Posted March 7, 2009 (edited) Ive worked out pretty much everything on my spfi swap on to my ea81, but I just cant seem to get my idle as smoothe as I had expected. It idles down around 700-800 rpm The timing fluctuates between 20-22 deg. due to the miss. After some searching I found some old posts with similar complaints, one from G.D. ended with him blaming engine internals. It made me start thinking back when I first got the car the idle quality was never consistant no matter what. I cant remember wheather I just got used to it or resolved it completely but it was smoother but also higher than it is now. Ive checked over everything, perhaps I need to readjust my valves, hasnt been that long but maybe I didnt get it right. its kinda starting to tick me off. G.D. Did the rebuild solve this on yours? Or did you find a resolutiion? Edited March 7, 2009 by ihscout54 Link to comment Share on other sites More sharing options...
Truckerman666 Posted March 7, 2009 Share Posted March 7, 2009 It sounds like the valves are tired. If it goes away at a higher speed, you will need to consider a valve job. Link to comment Share on other sites More sharing options...
ihscout54 Posted March 7, 2009 Author Share Posted March 7, 2009 Its been a while since I did a compression test, Ive been meaning to do one, and it is a possibility I have an internal issue. I was just hoping one of these boys/girls who have been through the SPFI swap might have had this problem, and found the solution. I did notice backing off the timing smoothed it out a bit, but the miss is still there. But it really impacts acceleration. Link to comment Share on other sites More sharing options...
Quidam Posted March 9, 2009 Share Posted March 9, 2009 One easy thing to do: Put a vacume gage on it and see what happens. Doug Link to comment Share on other sites More sharing options...
4x4_Welder Posted March 9, 2009 Share Posted March 9, 2009 It sounds like a vacuum leak. A leak at one end of the intake will only affect the cylinders at that end. Link to comment Share on other sites More sharing options...
ihscout54 Posted March 9, 2009 Author Share Posted March 9, 2009 Im gunna stick a gauge on it, maybe tomarrow... Link to comment Share on other sites More sharing options...
Scarpachy Posted March 9, 2009 Share Posted March 9, 2009 I don't know which motor you have in there. But if it's a single port, EA82 series. A lot of times the purge control valve on passenger side head sticks in open position. Causeing a lean condition on those two cylinders. Allowing atmosheric air to suck in on that side.Take some needle nose and pinch it off where vaccume line hooks into intake on top. See if that effects it. Also very common are cracked heads between the valves. Almost every head you pull out of those engines, is cracked. Sometimes it wont effect runnabilty. But other times the crack may have led up to the valve seat. Causing leaking compression. Other times, it can crack to where, it causes overheating issues. Or could just be low idle miss, from weak valve spring. Valve not seating from carbon build up. Or just worn rings. If older EA81. Yeah could be a tight valve you could adjust. Otherwise check the obvious, wires,plugs, vaccume lines. Intake gaskets. Spray carb clean around and see if it idles up. Plug condition could give a good indication of the condition of the cylinders. Link to comment Share on other sites More sharing options...
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