Car running rough and stumbles - no power.

[BLACK6PACK]

Need some help here. I just installed Direct Scan, a SMC EGT and a Max Effort chip. The car idles like it is on 3 cylinders, but after it warmed up it smoothed out a little. I can give it gas and it will almost take of somewhat normally, but if I go 1/3 throttle it starts stumbling and cutting out. I am getting no codes, and everything seems to be in spec on the scanmaster. The only thing that looks fishy on direct scan is the gear indicator. The highlight box seems to be jumping around and flashing on 3,4 and PN. I took the max effort chip out, reset the computer, and went out for another drive, and it didn't help any. Last time I drove it, was about a week ago, and everything was fine. TIA

 

[Roger]

Go back to your original configuration to see if anything you did is the trouble.
Kinda sounds like a ground trouble.
Possibly a splice isn't tight, most of us solder our splices.

 

[dgreene]

You might try unplugging the DS's ECM connector. If that straightens it up, clean the connections one more time and push the connector on again. Make sure it's not pushed to far on as that can cause the problem you described.

Hope this helps.

 

[BLACK6PACK]

Well, both of you were right, with dgreene hitting the nail on the head. I unplugged the DS cable from the ECM, Reset the computer and she ran fine. I guess the 3 hours of scrubbing the connectors wasn't enough. Thanks guys!!!

 

[dgreene]

Glad to help. Try cleaning the contacts on the ECM with MEK(Methyl Ethyl Ketone). The kind you get from the hardware store has to much water though, try picking up some from a local chemical company/distributor. I work for a company that prints billboards and one of the printers uses MEK based inks and uses it to thin the inks. It's 99.8% pure. Works like a champ on that nasty clear coat.
I also took the guts out of the shell when I was cleaning it too. That way I could see the bottom side better.

Good luck with that DS. You'll love it once you get it going!!