Runs very rough after ecu reset

[truegearhead]

I just fixed my vario cam switch and the car ran but it still won't engage the vario cam so I disconnected the battery and reset the ecu. Now it runs like hell/won't run. It has headers no cats a free flow muffler and no intake mufflers so maybe it just has a lot o learn? Seems doubtfull, also engine light! Any ideas

[JFP in PA]

Originally Posted by truegearhead

I just fixed my vario cam switch and the car ran but it still won't engage the vario cam so I disconnected the battery and reset the ecu. Now it runs like hell/won't run. It has headers no cats a free flow muffler and no intake mufflers so maybe it just has a lot o learn? Seems doubtfull, also engine light! Any ideas

Yeah, read the code and find out what is wrong with it..............

[truegearhead]

Ha, I ment no check engine light

[truegearhead]

Full story

Step 1) Four weeks ago the car died, dead battery. Replaced the battery and the car wouldn't run (misfire cyl 1-3)

Step 2)I changed out all the plugs and o2 sensors. No difference


Step 3)Took it to the shop and they said it was a bad air/oil separator and collapsed oil fill tube. They replaced it and the car ran.

Step 4)While in the shop the variocam switch failed on bank 1. They were too expensive so I took it to another Porsche shop.

Step 5) This week I got the car back, still won't rev. Looked online and it sounded like I needed to reset the ecu. So I disconnected the battery. Now the car won't run again, it runs just like it before I took it to the shop the first time.

Step 6) Shops are now closed so I ran the codes. Mis-fire on all cylinders(code for each), code for all 4 02 sensors (odd since they're new), and a electric throttle relay code (which is also odd since I have a cable throttle on my 97).

Step 7) In an effort to diagnose the MAF I disconnected it and and the car won't start at all, I tried cleaning it, no difference. When driving the car the engine light is now on, it stays on for a minute then starts flashing and the car dies (I had to get it home).

Any ideas?

[JFP in PA]

Using a Porsche specific scanner (Durametric, PST II, PIWIS), scan the car for all codes and let us know what you have. A flashing CEL is not a good thing............

[truegearhead]

Originally Posted by JFP in PA

Using a Porsche specific scanner (Durametric, PST II, PIWIS), scan the car for all codes and let us know what you have. A flashing CEL is not a good thing............

There is a shop locally that has a MAF sensor, I'm tempted to take a shot in the dark and replace it. The car has 120,000 miles and its on its original MAF sensor.

[JFP in PA]

Originally Posted by truegearhead

There is a shop locally that has a MAF sensor, I'm tempted to take a shot in the dark and replace it. The car has 120,000 miles and its on its original MAF sensor.

MAF's are not cheap, and rarely cause flashing CEL's, in fact the car can run just fine with it unplugged; I would not be throwing parts at the car until you confirm what exactly is causing the codes.

[truegearhead]

Originally Posted by JFP in PA

MAF's are not cheap, and rarely cause flashing CEL's, in fact the car can run just fine with it unplugged; I would not be throwing parts at the car until you confirm what exactly is causing the codes.

I tried unplugging mine to see if it would make a difference and the car wouldn't even start.

[j.fro]

I think your cams have jumped timing. Big issues, good luck, don't plan a vacation any time soon.

[truegearhead]

Originally Posted by j.fro

I think your cams have jumped timing. Big issues, good luck, don't plan a vacation any time soon.

THen why would it run fine before disconnecting the battery?

[JFP in PA]

Originally Posted by truegearhead

I tried unplugging mine to see if it would make a difference and the car wouldn't even start.

Very unusual as the MAF does very little below about 2,500 to 3,000 RPM.........