It's Always Something...

SickWhip

Registered User
Hey Guys,

My 94 SC has developped a small problem. Sometimes, the car's idle drops below 500 (stopped at a light,when in gear), and sometimes stalls. I was wondering what may cause this. I searched the forums, however did not come up with anything solid. Once in a while, the check engine light will come on, and stay on for about 2 mins or so, before shutting off. Where should I start? I'm sort of new at all this, but my Popps is a Mechanic, it's just hard to get him to take a look at it, unless I give him some info. MAF? IAC? Any input would be appreciated guys! THanks in Advace. Have a good weekend!

Joel
94 SC Auto
 
do u have a code reader? you might wanna pull out the codes first. it can be your IAC going bad. Vacuum leak perhaps. Trying pulling the codes first and work from their.
 
if you can buy a code reader then go for it. Or you might wanna consider just taking it to a shope to get the codes. then you might tell us what codes u got and we can go on from their. Check for VAC LEAKS first though. PVC (PCV) area and other spots.
 
You can buy a code reader at walmart for 25, I think. Autozone will read your codes for free. Report back to the codes you get, or on second thought, do a search for those code #'s first. Good luck!
 
With my 94 it did not store any codes and did the same thing you described. It was a $29.00 cam sensor and was easy to change.
Still run the codes and see what you get first. Mark J.
 
If your dad is a mechanic he should have (or have access to where he works) a scan tool that does MUCH more than the $30 code reader you would buy, all that is is a glorified paper clip really, simply jumps across 2 terminals in your diagnostic connector and flashes a code with your check engine light...you literally can do the same with a paper clip. A real scan tool costs more in the range of $3000 and provides much more trouble shooting and diagnostic help. Unless your dad only works on cars built before 1980 he probably has access to one....that's where i would start.........
 
Be aware that the EEC IV, which has little to no OBD circuitry, can't tell you any more than what the feedback from the sensors tell it. For example, it might tell you that the engine isn't idling like its suppose to, but it can't tell you that the IAC isn't doing its job or that the engine mounts have collapsed such that the engine is resting on the subframe and that the resultant vibration is being picked up by the knock sensor and thusly retarding the timing. ;) ;)
So, saying engine mounts may sound stupid, but its not. And the EEC will be clueless about it.

Also, I like the paper clip. It takes a few tries to get the flash count right, but it works. Also, when "check engine" lites up, it means there is a stored code. Even if the light then goes out, a code for an intermittent problem will be saved which may point you in the direction of the real problem.
 
Poor Idle..I Can Relate

Though I did not figure the knock sensor piece, I diagnosed a sudden increase in engine vibration and poor idle to engine mounts. I was just looking at MN12 mounts and contemplating changing them.

Though with the age of these cars..anything could go.

Have fun figuring it out.
 
Back
Top