Car runnin kinda crappy.... and 10mpg.. help

[Datsunboy]

Guys, my car when cold idles like poo. The idle fluctuates like it wants to die. When warm it still idles rough. When its warm it idles like a lumpy cam would.

I am also getting 10mpg on the highway on a stock 85gn. Any ideas as to possible problems? It was a pretty windy day, and i like boost.. is 10 normal? I didnt spend that much time on the throttle! What are you guys getting for milage??


Thanks guys - Evan

 

[crazygn]

I get more then 10mpg with all my mods, i would make a check list and go over the hole car.

Check for vac leaks , exhuast leaks , cam sensor , tps , and check the plugs and plug wires to makesure every thing is on the money.

 

[tim87tr]

To start with, it may need a new O2 sensor, and reset the IAC per instructions on www.gnttype.org in their tech section (Bad O2 sensors cause poor mpg). Many useful fixes for a variety of common TR problems can be found there. If possible borrow a scantool to check the car for knock, O2 milivolts, IAC readings, etc. If using a scanmaster II, check the cross counts and that should tell you if the O2 sensor is bad, they should cycle about 40 counts if good.

 

[FJM568]

Needs the 86/7 ecm upgrade to use Scanmaster on an 85...

 

[Datsunboy]

Thanks guys, this site is very helpful. I am a buick newbie but not a turbocar newbie. I have a turbocharged datsun 240z. but since i used aftermarket FI, i dont have great factory EFI troubleshooting skills.

Ill look into the stuff you mentioned

Looks to me like i need to start with plugs and wires, they are pretty nappy lookin.

02 sensor seems easy to get too so maybe I should snag one of those too. Can you guys give me an idea as to what millivolts i should be seeing? I can put my multimeter in the car with me and take measurements and check if its bad.

Thanks again guys - Evan

Ps.. I am planning on doing the 87 upgrade sometime soon. Really need to fix the rough idle first though, its annoying!