Just putting the car back together after a long time being down. Had the motor and tranny rebuilt, everything is back together and in the car.

I loaded my maps from my last 93 octane tune on there just to try to get it running and make sure everything was OK. No problem loading the maps. When we tried to start the engine would not turn over, it just cranked and cranked. We checked everything, plugs, spark, injector wiring harness will light a noid light, injectors do fire when hooked to a tester, Cam angle sensor is seeing the right values, all the evoscan logs look pretty much as you'd expect for an attempt to start.

We hooked up an oscilloscope to the injector harness and noticed that the pulse width was about half as long as you'd expect and that the signal strength decayed rapidly during the attempt to start.

So that leads me to think it may be the capacitor in the ECU that is bad since it (should) be controlling this injector pulse. I tested it with a multimeter to the best of my abilities without being able to get it off of the circuit board and it does seem like it is not testing within spec.


Questions:
A) Has anyone seen this before? Are we totally off base in where the problem might be?
B) Is this capacitor replaceable at all or do I absolutely have to buy a new ECU? The way the board is made you cannot really access the mounting points for the Cap and the dealers obviously don't want to touch it.


Help!!


Edit: The only MAJOR change since my last tune is new cams. I went from the BC 272s to GSC S2s. I'm all ears if it's something I have to change in the tune to even get it to start. That would be a huge relief. Please tell me I'm dumb and missed something.

 

Follow up question, if I do need a new ECU do I have to buy the ignition/imobilizer with it? Most of the ones I see on Ebay come with that as a package.

 

According to the shop manual to replace the ecu all you have to do is reregister the keys. There is a differnt immobilizer hex in the new one. You might need a replacement key switch with the key. I have the same problem right now. No fuel pump, no injector pulse and no power to coils.

 

or you can disable the immobilizer via EcuFlash to see if that works?

 

While the injectors firing or are receiving a signal to fire, are they getting fuel? ---did you see if you needed to prime the fuel pump--so that you have fuel to the rail... I know, just asking-- and the same with the spark--are you getting spark at the coil? good luck.

 

Spark at the coil was confirmed with a noid light. Injector signal was measured with an oscilloscope. I can host the video.

We used an injector tester to verify they would function and they did release fuel into the engine.

Would anyone be willing to look at my ROM and double check for me that I haven't gotten something messed up in there?

Thanks for the help.


Edit: video of the oscilloscope hooked into an injector harness slot

https://drive.google.com/file/d/0B3B...ew?usp=sharing

 

Update: Fuel pump was totally locked up. Got a new one and she's alive again.

 

sweeeeeeeeet. cheap and easy. just how i like them. problems and women.