Holley Commander 950 mpfi won't fire!
 

Hey guys, was looking to see if anyone may have some insight or experience with the Holley Commander 950 mpfi fuel injection systems? I have been running them on my 31 Scarab all summer and they have been working flawlessly... To make a long story short it spun a bearing at 5,000 rpms and destroyed the engine, so i just rebuilt it and went to start it the other day, & it fired right up and sounded great, ran for 5 seconds and shut off. Did that 2 or 3 more times and now it won't start at all. Just cranks. My fuel pump is kicking on fine, and it has good spark. All i did was unplug all the connectors and set it off to the side while i built another motor and then plugged it all back in, i don't see how doing that could have caused a no start issue especially since it worked great just a week before and fired up 3 or 4 times right off the bat? These ecms are tuned at a shop a while ago and i don't have the software or anything on hand. Is there anything simple thati should check before throwing in the towel? Shootout is next weekend and I'm getting pretty desperate... Thanks in advance

I don't mean this as a smart ass response, but is there gas in the tank? Sounds like a fuel issue if it ran then quit and spark has been verified. Check all the filters and lines from the tank to the injectors. Do you have fuel pressure at the injector rail?

It's all good i welcome all questions. Yes there is gas in it, i put more in it and even put it on a hill just to be sure. The other engine starts right up fine and Will run as long as you want it to. The fuel pump is kicking on and fuel getting to the rail. Gonna check fuel pressure tonight to be sure

I'm guessing fuel at this point still based on the behavior you described (ran for 5 seconds, quite, ran for a few seconds quit, etc.).

Did it stumble and quit or sound like you just shut it off with the key?

It shut off very fast, almost like a backfire shut off on a carbed motor just not as violent. Had to do family crap all night tonight but I'm getting a sitter all day tomorrow so i can get it figured out. I brought home a few different fuel pressure guages, noid lights for the injectors, power probe, spark testers, ect. If i can't find it fast I'm gonna start swapping relays, boxes & distributers ect from the running motor to see what's up. I'll keep ya posted, tomorrow is pretty much my only day to nail this down so wish me luck :/

I'd look at the switched 12,sounds like its getting a start voltage but run voltage may be missing and everything is shutting down.

Try swapping the ignition switches. And bypass any safety stuff.

Check your firing order/wires?

Rub 200 rabbit's foots ! And make sure your good with the Big Man upstairs !

Ok the engine has plenty of fuel pressure, the injectors are pulsing, it has spark, it has rpm signal, & i pulled it to TDC 2 more times and reset the distributer to be 100% sure. I've swapped fuel pump relays and distributer relays and nothing changed. Spraying starting fluid did nothing. I'm lost