Help I have a 92 sho and have a problem

[CSTYLESONE]

I own a 1992 SHO. I am having a problem where my car runs fine and every now and then the check engine lite comes on and the idle rpms drop. This problem has caused me to replace my cats because i was told the car is running to rich. I had read on shotymes that the thermostat maybe stuck open and that causes the car to run rich . well i replaced that. I still have the same problem. I have changed the o2 sensor and still can not figure this out. can some one please help . I don't want to spend money and not fix the problem.

 

[AutoSHO]

Does the car completely stall? Does it restart directly after this? Does the tach falter and then drop or does it completely drop as soon as the CEL comes on?

 

[CSTYLESONE]

The car does not stall at all.The rpms at a idle or even when i'm driving. Its funny because the car will run as if nothing is wrong and then with out any notice it drops it's rpm and runs differently , sounds different as well .

 

[Mr Anonymous]

Step 1: Read your codes. There are links in my signature to three sites with instructions on how to do so, and you can use something as simple as a paperclip or short piece of wire. Report back to us what you find and we can suggest the next course of action.

 

[CSTYLESONE]

One problem, when the problem doesn't happen it reads everything is fine, when problem happen it says that the fuel pump is not working right .

 

[CSTYLESONE]

What i don't understand is why would the car run normal and out of the blue start going bad and the go back to normal and then start trippin?

 

[masho95]

Well the first thing you should have done before replacing parts was to pull the codes. This is the best place to start while trying to diagnose a problem with the car. Although it won't always say "replace this part" it's always a good place to diagnose a problem... especially with the CE light coming on! Who told you that your car was running rich and what was their reasoning behind that? Start with checking the codes and go from there.
http://dalidesign.com/hbook/eectest.html
http://www.midwestsho.com
Both of those links are excellent places to start learning about checking codes.

 

[CSTYLESONE]

I did just that , I had sho shop in orange county check it out, they told me the crank shaft position sensor needed to be replaced the voltage was not strong enough going to the spark plugs.
I took it to another repair shop, they told me that the fuel was not working properly.

 

[CSTYLESONE]

I was told i may have a lack of compression or to much compression. And they wanted to charge me 2500.00 to rebuild the motor.

 

[Mr Anonymous]

CSTYLESONE:
One problem, when the problem doesn't happen it reads everything is fine, when problem happen it says that the fuel pump is not working right .

The PCM (computer) stores codes any time the CEL light is tripped. Even if the problem isn't occurring at the time you read the codes, the stored codes should still spit out. What specific fuel pump code are you receiving?

CSTYLESONE:
What i don't understand is why would the car run normal and out of the blue start going bad and the go back to normal and then start trippin?

This is what is called an intermittent problem. Many problems with any car ever made are often intermittent.

CSTYLESONE:
I did just that , I had sho shop in orange county check it out, they told me the crank shaft position sensor needed to be replaced the voltage was not strong enough going to the spark plugs.
I took it to another repair shop, they told me that the fuel was not working properly.

Again, read your codes and let us know exactly what codes, by number, are stored in your computer. Your problem could be ignition system related, fuel system related, induction system related, or a matter of a defective sensor or component.

 

[LOUDSHO92]

I think that it is the EGR valve. You might have a leake in the pipe going to the EGR, I had the problem you are desribing. The hole causes your car to run rich because it keeps sensing air. Have the pipe welded up and you should be fine. The code for the fuel pump is nothing. It happens when your car doesnt start right or somehting like that.
The other problem maybe the DIS modual going bad but I would think the EGR. Pull it out and check it.

 

[CSTYLESONE]

I don't have an Egr valve because the car if from texas.

 

[masho95]

There are very few codes that will actually throw a CE light. Parts that could throw a CE light include, ACT, ECT, TPS, 02's, and MAF. Those are the only sensors that actually will illuminate the CE light. Of course something else could be making them throw that, but those are the sensors that the CE light will illuminate for.

 

[CSTYLESONE]

Ok , i tried replacing the mass airflow sensor , that was not the problem and i have also changed the o2 sensor still not it. i even changed the electronic ignition , still had same problem. so I've been doing process of elimination.. man it becomes costly. The car it self has 120,000 miles. What do you think? On sunday I'm going to have a guy get me the codes that it's giving. But I could really use some help. I mean I love the car. But hate the problems....

 

[Mr Anonymous]

If you can't find a paperclip so you can read them yourself, you can also take the car to AutoZone and they will read the codes for you for free.

 

[Whiner]

CSTYLESONE:
What i don't understand is why would the car run normal and out of the blue start going bad and the go back to normal and then start trippin?

Mine is doing the same thing. I took it to get diagnosis, they said if nothing happens then they cant tell me nothing. Weird.