YACT: So my check engine light came on yesterday...

[cavemanmoron]

Originally posted by: Ornery

While I see your point of view and I myself love older cars I find working on the new cars rather easy. The same rules of mechanics apply to the basic stuff and if the problem is electronic in nature I can use a scanner to have the car tell me what is wrong with it in a matter of minutes. I have gotten so used to the newer computer controlled EFI engines that I am completely updating one of my 66 Mustnags with all new drivetrain from a 93 EFI car.

Swell. My son's '95 G. Marquis stalls when it's first started, but runs fine after a restart. It throws no code. Now WTF am I supposed to do with that? Start throwing $50.00 parts at it, one after another? Let a mechanic throw parts at it for $75.00 per hour, plus the inflated price of parts? Pisses me off...

First I would replace the fuel filter,then second;
replace the mass airflow sensor.
They are a common problem,
newer cars are nice when they run good,but a real pain when they act up.

 

[Ronstang]

If the car runs great with great mileage other than it dying on a cold start then I would be comfortable in saying that it isn't an injector/filter/pump and it is more than likely the idle speed control unit. You can clean it but that may not solve the problem. If cleaning helps in anyway I would suggest you replace the unit if problems persist.

 

[Aftermath]

Originally posted by: Ornery

While I see your point of view and I myself love older cars I find working on the new cars rather easy. The same rules of mechanics apply to the basic stuff and if the problem is electronic in nature I can use a scanner to have the car tell me what is wrong with it in a matter of minutes. I have gotten so used to the newer computer controlled EFI engines that I am completely updating one of my 66 Mustnags with all new drivetrain from a 93 EFI car.

Swell. My son's '95 G. Marquis stalls when it's first started, but runs fine after a restart. It throws no code. Now WTF am I supposed to do with that? Start throwing $50.00 parts at it, one after another? Let a mechanic throw parts at it for $75.00 per hour, plus the inflated price of parts? Pisses me off...

It might not be of any help, and I know you know more about cars than I do, but I thought I would offer this: My '91 Grand Marquis had the same problem. Turned out to be a sticky butterfly valve. A $2 bottle of carburetor cleaner and five minutes of time to clean it down solved the problem beautifully.

 

[dmurray14]

Heh, you haven't seen anything. My father has a BMW 745Li, and the whole thing is a big computer. For a while, the car was running very rough, and when you shifted into gear it would jump a bit. Sure enough, they stuck a CD in the dash and updated the software and fixed it. This is the case with 80% of the problems he goes in for...they just pop in a CD to fix it..

Dan

 

[Ornery]

It's $45 at Autozone, and $50 - $55 everyplace else. My wife says I might as well just replace it as long as I have it apart. I asked how long it takes her to earn $50, and she shut up.

I succesfully cleaned the MAF sensor in my car with some brake cleaner, which saved me $60.00. I'm willing to try to clean the IAC valve before buying one. I'm cheap, I admit it!

Edit: Thanks Brandon, I'll try that first!

Edit II: I forgot to mention that it was Quixfire who clued me in to cleaning the mass air flow sensor earlier this year:

"As for the MAF I'm thinking it has dirt on the wires that could be cleaned with electric part cleaner..."

 

[glenn1]

Or you can do what I did with my Integra once I realized the check engine light comes on around every 10k or so for no apparent reason, since I keep my car well-maintained. Namely locate the little button under the steering column which turns off the "check engine" light and ignore it.

 

[Toastedlightly]

lol, in my car, if that light goes off... i gotta get a new bulb.

 

[Ronstang]

DO NOT spray brake or any cleaner inside of the throttle body!! It has a special coating that is designed to inhibit buildup of gummy deposits and any cleaner you use except ones specifically for the purpose will deteriorate the coating and cause a bigger problem than you have now. You can use a little Wd-40 on a paper towel to wipe it clean if you like but just don't soak it as you want to keep any solvent from being on the coating too long.

 

[Ornery]

Hey Brandon, I owe ya! Before and after! Starts and idles perfectly now!

Edit: Used throttle body & air intake cleaner by STP.

 

[Ornery]

Shoot! Thing worked great till this morning when it stalled on the first start. Hasn't done that since the morning of the 17th, and had been doing it consistently when cold up till then, for a couple weeks.

Even after cleaning the throttle body, which I'd like to do a little more thoroughly, it would rev up to a higher RPM on startup, than I would think is acceptable. Within a second of the high rev, it would settle down to a normal idle (if it wasn't doing the stall thing). I told my son I'd be cleaning the wires in the mass air flow sensor, and now I'll probably check into cleaning the idle air control valve. Wouldn't hurt to pull the throttle position sensor, and clean it as well. Dang, I forgot about the fuel filter. Sounds like a couple hours of work ahead of us...

 

[thomsbrain]

Originally posted by: SuperTool
On my Maxima, you don't even need a scanner. You just turn a screw on the ECU and it blinks the error codes with the check engine light. You can also reset it with that screw.
I had an evap system code last week, but then when I came back from a plane trip this weekend, it went away

it's similar in my 91 accord. there are combinations of error lights and numbers of flashes that let you diagnose what is wrong. i was able to correctly diagnose a faulty vehicle speed sensor this way.