ok, i just got done rebuilding a AP1 f20c motor. Nothing wrong with the motor, but just wanted it to have new rings, bearings, gaskets, etc. Well, we finished putting it in the car and getting everything hooked up last night. The motor cranks, but will not start. Its getting fuel but no spark with the stock ECU. I put in my AEM EMS in and it gave it spark, but the motor still will not start. (edit...no spark at all anymore!!!

UPDATE: 3-8-09
Well, the crankshaft sensor ended up having a dent down the middle of it. Replaced that and the car starts now, but only for about half a second. Any ideas as to why?

UPDATE: 3-13-09
Well, i came to mess with it today and it doesnt even semi start like it used to. Nothing has changed since last week. I am soooo lost!

UPDATE: 3-22-09
Ok, i have spark, fuel, and compression! What else could it be? If the cams are not aligned, will the car still have spark?

UPDATE: 3-23-09
I put new gas in it and messed with timing some more. I tried to start it again and it was starting for a split second again. But when i opened the throttle a little bit it shot a fireball out of the intake manifold. Any ideas? Could it be firing in the wrong order?

Thanks
Fadi

 

So no spark with stock ECU but spark with the EMS? It depends what set of conditions need to exist for the EMS to provide spark. Like, EMS might rely on its own ground vs ECU requiring that additional ground on the back of the head by the firewall...
But I bet it's something simple, almost stupid.

Get a timing light, and double-check timing.

got injectors hooked up?

Pull out a spark plug. Sometimes they will foul out with fuel before firing up, then just dry them with a heat gun, or better yet, with a torch.

It would be nice to get a quick compression check...

Then confirm correct fuel pressure by installing a fuel gauge instead of fuel rail feed damper. Part # BMM-46054 from summitracing.com. You should have 38-46 psi at idle, and if you pinch the little hose going to the fuel pressure regulator, you should read 47-54psi.

Good luck and let us know what the problem was! It's good build up knowledge and troubleshooting techniques...

 

doesnt the car need to be running to use a timing light?

 

You sure that ground at the back of the head is connected? It's tough to see with the cam cover on.

 

ya, im 100% sure on that. The grounds on the back of the head, from the front subfram to the block, from the block to the driver side chassis, the 2 grounds on the front left and right corners, and the one by the battery are all hooked up. I dont think there are any other grounds.
How can i check timing if i cant start the car? Do i just have to take the covers all off???

 

Runs with AEM but not stock ECU:

Cam timing. S2k will not spark with stock ecu if cam timing is 1 tooth off.

 

No, it doesnt need to be running you can check it while cranking. It is probably the key, is the immobilizer in the key programmed for that vin on that ecu?

 

If that isnt it if you can try another stock ecu if you can get your hands on one.
Or what billman said cam timing could be off.

 

well even with the AEM it still doesnt start. It just gets spark where with the stock ecu it doesnt get spark.

If timing is off the aem will still start it up???

I dont think its immobilzer bc its the right ECU and Key. Plus it would still start with AEM EMS if it was the immobilizer..

 

changed the ECU out with the ECU in my running s2000. Still no start. I also rechecked the grounds and they are all good. I guess im just an idiot and somehow messed up on the timing. I checked and double checked though!!! Ill take it apart and see tonight.

Just to make sure

The white mark on the crank pulley is set with the mark on the cover.
Then set the front sprocket to where the lines are even on the head,
And then set the cams to where the lines are even on both.

Does that sound right? Does it matter if the TCT is on or off???

Thanks again for the help guys
Fadi