CEL Question

[diablo5969]

First off, yes, I assume there have probably already been 10 threads about this, but try searching "CEL" and you get 500 threads

Now, I've noticed over the past couple days that my CEL would come on when I was driving, stay on for a bit (never more than a minute), and then just turn off. It happened twice that I noticed on Sunday and once yesterday.

I'm assuming I shouldn't actually be concerned about this because it almost immediately flashes back off, but it still leads me to ask: Is there anything simple that could cause the light to flash on and off like this?

Now, the part that alarms me is this: About a month ago I was doing a little off-roading, and one of the first things I did was hit a mud puddle. The mud must've splashed up into the engine, and it stalled as soon as I pulled out of the puddle. I tried restarting it once, it didn't work, so we opened the hood and let it sit for 10-15 minutes, then tried again, and it's worked perfectly ever since. Could a little mud/water from a month ago be causing an intermittant CEL now?

Thanks for the answers

 

[lonestar]

poosibly, it could be a bad or dirty connection. or it could be a faulty part gonig in and out of range.

AutoZone will scan codes for free to see if you have any stored codes. Then you can make a decision on what to do next.

 

[Glacier991]

There are oh, about 100 or so things than can make the CEL come on in your 94. Some will be indicative of driveability issues (eg the damn thing won't run right) and others are not going to show up as driveability issues (eg it runs fine). Just because the light goes out, doesn't mean the computer "forgot" what made it come on. It will store DTC (Diagnostic trouble codes) for about 65 or so retsarts. I personally have driven a car for ages with a CEL on, but I knew what it was and it was not a driveability issue. When I finally got around to it I replaced the offending sensor (and the light went off). Best to know though.
HTH.

Happy Exploring

Chris

 

[rydinhigh]

My 95 was doing that for a while. I would scan the codes and nothing. I was talking to a guy with a mustang and he told me he was having the same problem and got rid of it by changing the 02 sensors. I changed both of them and haven't had a problem since.

 

[Glacier991]

With all due respect.... get your codes read. Do not just start replacing random things hoping it might solve the problem. If a CEL comes on the codes WILL be stored. READ EM. Please! (pulling out little remaining hair). People will not spend a dime on a code reader or scanner and hundreds randomly replacing good compnoents HOPING they get it fixed. (sigh) Please don't do that!

Happy Exploring


Chris

 

[diablo5969]

I wasn't planning on just randomly replacing parts, I was only asking if there was one incredibly common that tends to cause the light to be on like this.

I'll head down to Autozone tomorrow or the next day and figure out what the deal is.

Thanks

 

[diablo5969]

Well I finally got around to the Autozone today, and they said they can only scan codes for '96 and newer vehicles, so they couldn't tell me anything.

Something I should worry about?

 

[Alec]

An OBDI scanner is only about $30.

 

[MrShorty]

If $30 dollars for a code reader is too much, a short piece of jumper wire will cause any trouble codes to show up as flashes of the check engine light, or you can use a $3 analog voltmeter or other testlight. Go over the procedure at www.dalidesign.com and see if you're up to it.

 

[lonestar]

Originally posted by diablo5969
Well I finally got around to the Autozone today, and they said they can only scan codes for '96 and newer vehicles, so they couldn't tell me anything.

Sounds like the guy at AutoZone don't know what he is talking about. most 96 and newer are OBDII, where older cars are OBDI, it just requires a different scanner. They should have another scanner or atlest a chart showing how to use the voltmeter method, older GM's jusat require a paperclip to jump 2 terminals.

I called AutoZone about testing a MAP sensor. They looed the sensor up and said "yeah we can test it". So I stop by the store closest to my house and they say "no we can't test it". I'm like "I just called another store and they said you could. So he looks at a big sign on the wall, "starters, alternators, batteries, ignition modules, nope we can't test MAP sensors". SO then I go to the store that sais they could test it, look up the part, find a test number and then tell me, "we don't have all the stuff required to test it" (I guess they lost it) they call another store that has all the test equip in their test kit. Go there. Look up the part, find test number and pull out a whole manual with about 100 pages listing test procedures for various sensors. The first guy was just looked on the side of their super duper test machine and was like, it won;t test it. It seems most people don't know how to look anything up, if it's not in front of them or on the computer, it doesn't exist. Test manual, parts book what's that.

 

[diablo5969]

So I guess I'll just try another Autozone when I get the chance. Thanks for the heads up