I just got my new built motor put back in the car and bigger fuel system. The rail is seeing fuel pressure and the spark plugs are getting a good spark. something happened to my stock ecu idk what but it wouldn't prime the fuel system. Tried a buddies aem and it primes the fuel system and everything so I bought a aem. and sti the car won't start any ideas we haven't thought of would be great.

 

How is the comprssion?

 

Does it crank just not fire up? Are all the proper fuel adjustments made to make up for the upgrades fuel system? If the management is good and you have fuel & spark, check your timing or makbe a possible bad cas.

 

needs a tune for your new set up.

 

+1 on checking the timing. that will be the easiest and cheapest test. if the timing is on and it's getting fuel/spark, then you can move on to other ideas.

 

Checked the belt timing and is good. We tried all adjustmenta with the pulse width and start timing and still won't start.even tried my buddies tune with the same injectors and everything still nothing. The compression is good cylinder one is low compared to the other three but it's a fresh motor once it gets oil it'll probably build the compression up. Any other thoughts? You said about bad cas? Crank angle sensor is that what you meant? On the aem I believe that and the cam sync up but possible it still be bad?

 

If you have fuel, spark, and timing, there's no reason the car shouldn't run, really. Unless compression is ridiculously bad.
You're not getting too much fuel? Coolant temp sensors can cause that.

Just shooting in the dark here, of course.

 

AEM EMS needs the crank trigger plate. Stock ECU doesn't. What do you have on the car?

 

The AEM will run/start on a stock setup, however the starting sequence is much faster (or so I'm told) with the 12 tooth.

You mentioned your friends AEM did all the right things, have you tried starting it with his ECU/tune? When I was fooling around with the AEM v1, I very quickly noticed that the starting & warmup tables are very touchy.

Short of taking it to get a tune, I see two options provided everything is mechanically sound:

- Learn how to properly tune the AEM starting tables

- Slave in a serviceable stock ECU until you can get the AEM tuned.

 

Right now I currently have the aem in my car because some reason my stock ecu wouldn't even prime the pumps. A bad coolant temp sensor could cause this? I know there isn't any coolant in the system right now we are just trying to get a heat cycle on the car since it's the first start up. Also checked the trigger plate and looked normal. Also we tried flashing my buddies tune on my aem Ecu and the car still didn't start. I also heard about the aem Start tables are touchy and I don't have a stock ecu around that works.

 

Here's an update for everyone who is giving ideas. We were messed with it tonight and did some hard thinking and I remember my engine builder said my block is .023 under manufacturer specs so he machined the Pistons to match that basically because they stuck out the top of the deck at first. Pistons are also .20 over stock. Also I do have a buschur head which is oringed so that means it had to be milled At one point. With all that said I'm running an oem headgasket. With all that said that technically messed with the start timing of the car since the deck is short advancing The cams throw the rotation off. Correct me if I'm wrong but to resolve my issue I think I need adjustable cam gears to dial the cams into the correct time so they match when the injector pulse goes off, because right now the spark isn't exactly at the same time it's after.

 

That's what I was going to say. Probably the cas