Feels Like a Part Throttle Miss

[ed1948]

-86SS, 305, stock, all emissions in place.
While cruising today around 40mph I noticed it feels like an intermittent miss every few seconds but not steady - every 100 or 200 feet. At that speed the torque converter is locked. I thought it may be roughness on the road. Idle seems smooth, no CEL, 1/2 tank - just noticed that today. I actually have not peeked under the hood yet. Has lots of power at WOT. Plugs were gapped and cleaned perhaps 500 miles ago.

 

[airboatgreg]

I would look at a plug wire or a cracked spark plug porcelain. Spray soapy water on plugs and wire boots at night while engine is idling to see if you have a miss

 

[melloelky]

I would look at a plug wire or a cracked spark plug porcelain. Spray soapy water on plugs and wire boots at night while engine is idling to see if you have a miss

why @ night?

 

[ed1948]

While dark it's easier to see wire or plug arcing. I sprayed the wires, dist and plugs with water mist= no blue arcing or snapping sound heard. I just returned from a test drive and I don't think I felt any miss. The weather is dry - no humidity to cause electrical problem.

 

[airboatgreg]

While dark it's easier to see wire or plug arcing. I sprayed the wires, dist and plugs with water mist= no blue arcing or snapping sound heard. I just returned from a test drive and I don't think I felt any miss. The weather is dry - no humidity to cause electrical problem.

May have had a piece of carbon or some trash. Hopefully it is gone

 

[pontiacgp]

Like you said it could have been the road...

or it could be

 

[Dayzedandkonfuzed]

Had a similar issue with the 305 in my malibu. Would come and go, usually under heavy load. 2 or 3 of the 8 new plugs I put in were cracked.

 

[malibu79]

Check definitly the plugs and wires...i had issues after installing new wires and got 2 of them crossed what he obviously didnt`t like Also had one or two plugs missing under load at 40-60mph and new plugs fixed it! Your problem is 95% ignition related, Check or change plugs and/or wires and you´re fine...

 

[pontiacgp]

we had a problem with an intermittent miss on our G body (metric) circle track car and it turned out to be the ignition module