So I changed my oil (redline 5w40 with oem filter) and cleaned my throttle body the other day, after this my car has been running rich and shuddering at lower revs at part throttle. If I give it more than half throttle the shudders stop, also they are worst from a stop. If i give the car alittle gas when at idle the revs drop really low before going back to around 1k. Im thinking it has to be the MAP just by process of elimination, however im not really that tech savie so any help in figuring this out would be appreciated. Thanks in advance.

 

hey, i recently serviced my car after i bought it as it was jumping from just starting off, similar to what you say. I changed the oil, filter and plugs for Denso Iridiums and it seems fine now Have you got any mods on the car and what fuel are you running?

 

I haven't changed the plugs, thats somthing I need to do.
No mods, just run it with the cover off the intake sometimes.
I tend to run shell however my last tank i put some other stuff in it, forgot what brand it was, its a station right by a freeway so i doubt its old gas, I put a bottle of redline fuel system cleaner in it also.

 

What octane rating is it cos you guys have different stuff to us over there right? I always run mine on Shell v-power 99 octane or if i cant get that theres a few stations do 97. I could just be a dodgy plug thats causing you the problems. Either go for NGK laser iridium or Denso iridium, they are far better than anything else.

You should invest in a few mods - filter/exhaust etc, made the world of difference to mine

 

i run 93, nothing but. I doubt its a plug, it ran just fine before i changed the oil and messed with the throttle body, and ran like crap right after.

 

Did you take the thottle body off to clean it or just spray some cleaner through it?

 

check all your vacuum lines and everything around the throttle body. And make sure everything is hooked up and correctly so.

 

Yea, i took the throttle body off, unpluged and removed the MAP while doing so. I've checked everything in the area around it already, however another check wouldn't hurt. What in particular if not connected properly would lead to these symptoms?

 

how dirty is your air filter? if you are running rich its worth a check.

 

repaced it like four months ago, looks brand new.