im going to be looking at my friends car tomorrow and was hoping for a little extra help of where to start looking...its a 99 maxima 3.0 automatic.

symptom:
jumpy when idling but not when in park only in drive, he said the engine is "jumping up and down" when idling and coming to a stop but idles smooth when in park?....any suggestions on where to start looking, plugs and coil packs were changed last year.


i know its not a honda thats why i posted in "off topic" just thought maybe someone could help

 

Scan for codes, could have vacuum leak, TPS or IACV valve malfunction.

 

no codes, but i was thinking maybe a vacuum leak....

 

I had a 94 , fuel injectors were a common thing on that engine. You can measure the resistance on each one pretty easy . If I remember correctly they should read some where between 16 - 25 ohm's , I think my bad ones read in the 50 - 60 ohm range. Don't take those values as absolute but you should see a noticeable difference between them if there any bad ones.