Guys,
I have an '87 Max automatic that upon startup idles terribly rough and will eventually cutoff. If I keep it revved to 1000 or 1,500-rpm then it is still rough, but it won't cutoff. Once I drive the car about a mile it warms up enough to not be a problem. During cold weather it starts and idles fine, but warmer weather makes it idle like crap until the car is running for a few minutes.

Do you guys have any thoughts? I was thinking it might be the O2 sensor, but the car should run poorly the entire time if that was the case. So now I'm thinking maybe the EGR valve?

Thanks for any help.

 

The EGR valve shouldn't cause that...

It could be the Aux Air Valve...most of the time, it fails, and affects cold-weather starts, but if it freezes in the open position, it could consevibly cause a hot-start problme...could also be the CHTS or the O2...

 

Yeah, if it was the EGR valve, you would have a bad idle no matter the engine temperature. A.A.C valve would be your first bet. Then I would start looking for possible vacuum leaks.

S

 

Thanks guys. I will check into that!

 

you might want to check the map sensor sometimes they will cause bad idle at certain temps when they start going bad

 

Ok I have had the same problem as this guy but now mine has gotten worse it misses and stalls now when it is warm. It would only do it when cold but now all the time what is wrong???

 

I have the same problem on my '83 810/maxima, rough idle then clears up after it warms up. I know what the o2 sensor is and Im going to check that but what is the A.A.C and Map sensors. Are they cheap to replace and/or check to see if they work? Thanks for helping this poor noob out.

 

Could it be leaky injectors? How could I check? For me the weather has little effect.

 

Check the Air Regulator and Mass air flow meter. Most likely though, you need a complete tune up (plugs, plug wires, fuel filter, distributer cap, etc...). That did wonders for my 88 Maxima that was doing the same thing that yours is doing now.

I replaced my Air Regulator last winter and that made my car idle up at cold start so it would stay running unitl it warmed up, but the tune up is what really fixed the performance problems.

 

Iv replaced the fuel filter and spark plugs. The the wires, cap, rotor and air filter look good. I think the wires are good, but I might replace them in the future.

Any tips for looking at the air regulator? Like I said im waiting for my repair manual. Lets hope it covers that.

And the mass air meter is 250$, screw that.