Ecu problem's

[konigtalon]

We'll it's happened again every time I get my car running something weird happen's and it tear's up again. I turned my boost down to 14 psi on my rebuilt engine have been taking it easy on it. I have a baby on the way and wanted to make sure I had something dependable to drive and not waste my money on fixing it everytime I break it. So anyway's I was coming home one night running 34mph and I hear this popping sound under the dash the car loses power and I pull it off to the side of the road not really knowing what to expect I checked the fire, fuel, all reasonable explanation's. We'll it turned out being one of the chip's on my ecu had blew up. I then checked the mpi fuse and it looked fine I tryed to get the car to start with a different ecu numerous time's and it never wouls so I though it was the fuel pump we'll it turned out the mpi fuse was blew just varely cracked on the outside. I had went through the whole wiring harness looking for bad wires and checking for short's replace it all and make sure I did it right using my old one for reference and also the pin point's and wire color's from the dsm manual. Now when I get my car started it is running rich according to the wideband my reading's are 10.7 to 11 at idle and when I try to give it gas it will not even rev up it just fall's on it's face and black smokes like crazy. I have checked the turbo it's building boost and no shaft play turn's freely, checked for boost leak's can't find any it act's just like the intercooler pipe blew off but it's fine. Im exhausted at trying to figure out what the problem is. Any one out here has any suggestion's or would be willing to come take a look at it?

 

[yokotabrat]

Can you get a picture of the ecu that shows the blown chip? That will help diagnose the problem.

Any check engine lights? Do you have a logger?

 

[konigtalon]

Nope no check engine light's the ecu is on it's way to get fixed hopefully . Also I should have clarified that the ecu im using now is out of a 1991 fwd turbo car no trouble code's when I run the diagnostic test on it. Yeah my logger took a dump on me also. I just don't what could have went wrong the car was running fine until the ecu did this now I can't even drive it.

 

[yokotabrat]

When you put in the 91 ecu, did you swap pins 6 and 14? If not and your idle switch is working like it should, your car will run like you are describing.

 

[konigtalon]

Yeah I swapped those two wire's still does the same thing. I thought my maf could be the problem I have a 2g maf but with it unplugged it does the same exact thing it does plugged in.

 

[yokotabrat]

The ecu you have in there now, is that a known good ecu?

 

[steve]

Let's see:

Old ECU blew up.
Changed wiring harness.
Blown MPI relay.
Logger no longer works.
Run run but poorly and blows black smoke.

I'd check the current ECU for a blown sensor ground.

 

[konigtalon]

How would I check it for blown sensor ground steve also the logger quit workig before my ecu blew up. I checked all the ground wires is that what you are referrig too?

 

[snowborder714]

A bit of info.
blownsensorground [ECMTuning - wiki]

 

[konigtalon]

Thank's man but I really don'w think that is the problem. The ecu looks fine as far as that goe's. I also used the end of the wiring harness out of hte 91 talon I have just so I could use the connector's would this have anything to do with it? I followed the wire color's according th the dsm manual and also used my original wiring connectors to go by to make sure I don't get nething messed up. The wires that ground the o2 sensor and the knock sensor could those cause this? I mean there securely grounded to the same place buy I had to cut the and put in fresh wire's that is what I believed caused the first ecu to fry the wire's were crispy all of the ground wires that ground right behind the stereo.

 

[yokotabrat]

Which wire harness end did you swap? The ecu connector ends? Was this when you swapped pins 6 and 14? I'd still maybe try swapping those two pins again assuming your ecu sensor ground is still good. Depending on when you swapped the pins and the harness being changed, you may have reverted back to the original configuration for pins 6 and 14.

The knock sensor ground wouldn't cause this. If that weren't connected the ecu would just throw a CE light, but still run fine.

 

[konigtalon]

Yeah I tried the wires both way's and yes it was on the connector's end's. U didn't think that the knock sensor would cause this either. I checked the timing marks on the cam's they line up fine checked the fuel it's getting fuel way too much . It's getting fire the only other thing I can think of is that it's not getting enough air but why? Turbo seems good and I never had ne problems prior to this it has no shaft play but it a little hard to turn doesn't really spin freely I called about it and they told me that was fine that it had to be on a thin cushion of air to spin freely. I really can't figure out what the problem is I mean the ecu checks out with the diagnostic test but could it still be bad the cas is new. everything checks out fine but I still get this problem also the boost gauge is way off from the after market one it will be reading 14 and my aftermarket is on 0. I took the plugs out and they are black.