Check eng. light....strange...

[hardtorn]

Well I have found a strange problem... well strange for me. In my 92 mtx the check engine light will come on. But only after I go over 80mph. And not every time. Some times it will stay on for 1-2min. other times it's off within a few seconds. Today I had an hour and 1/2 drive each way to a gymnastics comp. Through the trip the light came on and off many many times. Never for the same amount of time. The car is running great. I have a small coolant leak. (need to add after 3 -4 days of driving) But the coolant light was not on today. The check engine light only pops on after I have been driving over 80mph. Well that all I can figure on for now. I have nothing really to go on other than that.
I never see the light come on around town.
I have only had the car about 30days... I replaced the ECT sensor for the coolant gauge to work. Found the minor leak/leaks on my coolant system. Most SHO's I have seen leak a bit (if they have orig. radiator) Not really worried about it for not. Will get new double core this summer.

Any Ideas???
thumbs_u

<small>[ March 09, 2003, 06:14 PM: Message edited by: hardtorn ]</small>

 

[luigisho]

Computer codes are thrown when the check engine light come on. Check the EEC IV links here http://www.dalidesign.com to do it yourself. Could be a variety of things. The codes will point the way.

Any mods like an aftermarket MAF?

<small>[ March 09, 2003, 06:45 PM: Message edited by: luigisho ]</small>

 

[Mr Anonymous]

As luigisho said, checking your codes would be the best place to start. There are additional links for learning how to do so in my signature.

Purely speculation, but the behavior you describe is usually associated with TPS, 02 sensor, or EGR codes. In any case, let us know what you find for codes.

FWIW, the ECT sensor does not control the temp gauge, it only sends coolant temp data to the EEC. There is a separate gauge sender switch on the other side of the t-stat housing (about $7 at most auto parts stores). Did you replace the t-stat too? If the t-stat is stuck open (which is the most common t-stat failure we see in these cars), you could be running rich which might also be a contributing factor to the CEL issues.

 

[hardtorn]

No mods to the MAF or anything. Omlything I have done is remove the cone. It's winter here so I will wait for warmer weather. I thought of checking the "flash" codes for the problem. I just thought it was odd that it never was on for the same lenght of time or anything. I will get to it this week.
If i stay off the gas, ie under 80 mph or so it never comes on.