My 92 occasionally will idle really rough when I first start it cold in the morning.

I did recently replace all the plugs in the car but I have no idea what could be causing this.

 

if you just did the plugs i'd check those and your wires, i've had problems with that in the past on my truck, just go through and make sure all the wires are on nicely and go from there

 

Well would wires cause it to just do it on occasion? And it's not always when it is cold.

 

They could. So could cap & rotor. Changes in humidity can affect weak components like this.

 

Well I know that the cap and rotor are not too old but I think that the best thing to do would be to check the wires first and then what?

 

A sticking EGR valve, dirty injectors.

 

Well I also may have forgot to mention that the car won't pass smog either. The guy that did the smog said that it may be due to 1. The plugs or 2. The 02 sensor.

Well I have replaced the plugs and it does have more power and they didn't look too bad but I have yet to replace the oxygen sensor. Could this be a problem?

While I was driving home from school today I noticed that it would for some odd reason just spike itself up to 2000 RPM and not idle until I took it out of gear and gave it some gas. When i first started it, it idled just fine.

Also the injectors have a pretty good shaped spray so I doubt that is the problem. But I may be wrong?

 

check for vaccum leaks

 

Where would I check for the vacuum leaks at?

 

anywhere there is vaccumm (hate to be obvious) just fiddle with it and you can normally find them pretty eassy, the loud sucking noise gives it away lol, and i just ran into this recently too. My car has been jerking lately and we just had rain here in az, and a temp drop, so it will just jerk whenever it feels like it, i just replaced my alternator and plugs and wires today, and its got a rough idle now, i might have moved my dist. while messin with it i dunno im gonna check it in the morning. DOnt forget the check that egr too, if its sticking you wont pass, that was my problem

 

Well this will probably sound like a stupid question but where is the EGR valve? I checked the plug wires and one of them seemed to be loose but I may as well check the EGR since it may not pass again.

 

ok news flash! i just had this issue and i fixed it!!!!! After i bought my car a few months ago, i set the timing to 0 where its supposed to be, then last week, i bought new plugs, wires, and an alternator cuz mine was shot. So i instailled the plugs, and it got late, so i drove home and waited on the wires, the next day i put in my alternator, ran fine, then i put in my wires and the car went to crap, rough idle, high speed miss, the whole nine yards.....frustrated out of my head i went back and thought about what the problem could be. Then it hit me, i went outside and ohmed out my old wires and the resistance was insanely high, so peicing it together i grabbed my timing gun and checked it.....13 degrees advanced!!! Then i thought over it, and becasue my old wires were, old, the resistance raised making it harder for the current to flow, so when i adjusted it, it was fine, but after putting on new wires where the resistance isnt retardedly high, it was over advanced!

I bet if you check your timing its up WAAAAYYYY past zero.

Oh and the EGR vavle its behind your throttle body, and infront of your distributor its the round thing sittin like diagnoly towards the passenger side, its fun getting it off, just make sure you have a new gasket or some rtv for when you go to put it back on

 

No RTV on the EGR valve. It takes a special high-temp gasket.

 

Well thank you all for the suggestions. I am going to try and adjust the timing today and see where it is at. If not then I guess I will need to try and replace that oxygen sensor. Would the timing have anything to do with it smelling like it was or is running rich?

 

that dunno about, im used to having an air/fuel mixture screw but most of my work has been on imports, or carbed engines, but dont forget to disconnect the little plug before you time it! Its about and inch long and its on the passenger side by the firewall, its got a brown wire running to it, just disconnect it and time it, plug it back in when your done, if you dont the timing will reset after 1 drive cycle

 

Well I guess I may not be looking hard enough but I do not see what plug with a brown wire you are talking about?

 

Well I did find that plug after all, I just somehow overlooked it.
But I re adjusted the timing and it has more power and all the other problems have been fixed.

 

Something to keep in mind for the future is if you have a bad throttle angle position sensor you will get a real rough idle, not wanting to run, situation too.

 

good deal, glad you got it fixed, but just for reference, im holding the printed alldata instructions in front of me and it says: Initial timing 6~BTDC so if the last timing doesnt work just push it to 6, but my question is when i looked under my hood, it said to time it to 0. The only problem is at zero mine runs worse....so just trust alldata from now on?

 

Well I followed what the timing spec under my hood and that was 0. It ran sort of sluggish but when I unplugged that plug and retimed it and it runs great.