my 95 monte z34 has a ruff idle on cold start goes from 1000 to 3000 im trying to diagnose it so i can buy the part and be done with this problems i had codes pulled and said it was iac. put new iac didnt fix problem i cleaned maf sensor still didnt fix it surges until warm then check engine light is on but that goes away after one tap on the gas so i think im gunna need to buy a code reader. also i dont know if this helps but going up hill or just somtimes i hit the gas downa dn the rpms gauge doesnt move and doesnt have full power. the car has 190,000 miles to bhe more specific and i just want to solve this problem soon. i have been told it could be upper intake gaskets, coolant temp sensor, egr valve , maf sensor and ect once warm it runs great

 

Sounds to me like you have a vacuum leak somewhere. Get the code read first, it may tell you alot.