On my 94 Z28 I just put some pacesetter long tubes and egr block off on it bout three four weeks ago. Two weeks ago i was on my way to body shop to get it painted (it was raining on the way to the body shop) and it started cutting back and would finally pick back up and run strong. It never seemed to be at a lose of power. After the week in the body shop i got it back and it was doing the same thing after it basically sitting for a week, it was sunny and nice out when i got it back, and the service engine soon light was on. I've tried hooking scan tools up to it and they won't communicate with it. Any suggestions or anything on what it could be or how to get it to read if all my fuses are good and if i got power and ground to the dlc. Thanks for all the help.

 

Your scanner won't work because your car is OBDI not OBDII like everything '96+.

was your car reprogrammed after you removed the EGR? If not that's probably what the code is about. You're going to either need to send your PCM off to be reprogrammed or find someone locally that can reprogram it for you.

 

you need to get it scanned, dont try to play the guessing game, it can get expensive

 

I know it's obdI at the shop i work at we have obdI scan tool it wouldn't make communication to vehicle at all. Yeah i haven't got it reprogramed didn't think bout doing that. Over the last couple of days it's seemed to clear up and hasn't had any problems after I've put gas in it but the light still concerns me and no one locally can scan obdI

 

The "scan tool" wasn't one of those cheap Actrons that shorts the ALDL pins and tries to flash the codes on the SES light, was it? That won't work on a 94.

Free scanning software:

http://andywhittaker.com/ECU/FreeSca...0/Default.aspx

http://www.ttspowersystems.com/DataMaster.html

Just need a laptop and a cable:

http://www.akmcables.com/

 

no it was a gynises scan tool nothing cheap

 

Check your cigarette lighter fuse (accessory).

 

It could be many things.... the 1994 PCM is pretty darn smart when compared to some models of the same year but it can be very picky when it comes to communicating with it... it does not flash codes with the paper clip method nor will it communicate with many hand held OBD 1 scanners.

The best bet is to use the laptop scanning method. With an AKM cable and a laptop you can not only scan for codes but data log and troubleshoot almost on the fly.

From what you have said it might be a high probability the PCM is throwing an EGR electrical failure code. In other words If you removed the EGR solenoid the PCM will throw a code unless you program that out.

If that is the case you can try plugging the EGR solenoid back in to see if the light goes off.

 

I checked the fuse and it was in all that great so reinserted it and reconnected and read two egr and code 48 maf sensor circuit. So i started a datastream of it and the maf sensor was reading 99.9 g/s to me this seems high or is it within specs

 

99.9 grams/sec would be a very high load, at decent RPM and a large throttle opening. At idle, you would see anywhere from 6.0 - 10.0 gram/sec. Are you sure you weren't reading the barometer?

Read this:

http://www.injuneer.com/ScanMast.html

 

This reading is coming from idle and no I'm reading the maf sensor. But the car has been running great lately and not surging or acting like a normal maf sensor would do when it's going out that's what's got me. I'm jsut not sure which way to go with it. And again thanks for all the help

 

Is the MAF sensor aftermarket?

It could be dirty or damaged. Typical idle volume is around 7 grams/second. I can't see any automotive engine idling with 99 grams/sec of air.

 

That's what I'm not sure of cause I just got the car last and never had any trouble with til i started the headers and attempting to do bolt ons to it