[Marc L]

Started our 88 spider the other day and after running just fine the day before it now has a very noticeable miss at idle and lower RPM,seems to clear up around 3000 rpm.We checked for vacum leaks,checked the plugs,wires,cap and rotor...and it still is running rough..What am I missing ???????????

 

[ghnl]

Remove the oil fill cap while the engine is idling. If the idle does NOT deteriorate then it is likely there is an intake air/vacuum leak. (Removing the oil fill introduces an air leak. If there is already an air leak removing the cap won't make it worse.)

 

[jbane]

Started our 88 spider the other day and after running just fine the day before it now has a very noticeable miss at idle and lower RPM,seems to clear up around 3000 rpm.We checked for vacum leaks,checked the plugs,wires,cap and rotor...and it still is running rough..What am I missing ???????????

I had a very similar experience this past Saturday morning. I had driven the Spider (an 89) to work a couple of days earlier in the week, before it got too hot to enjoy it and it ran great. We had a big rainstorm on Friday, followed by very humid, hot weather. My Spider spent that time under a carport and under a Noah car cover. When I cranked it up Sat. morning to take a ride, the car stumbled at idle and at every gear change. However, after running on suburban streets for about 10-15 minutes, it smoothed out. I drove it again yesterday and today and it is running smoothly. My conclusion (I'm far from knowledgeable) is that maybe some moisture worked its way in a critical electrical connector (fuel injection controller?) and caused poor contact. Once the engine compartment heated up, the moisture evaporated and contact was restored. Other theories are welcome from forum experts.