TXFlyGuy

We have an off road vehicle with an LS376-525 crate engine installed.
The ECU is a MoTeC M130.

Engine cranks, but will not fire. We have spark and fuel. We have installed new batteries, and a new starter. It cranks a little slower than before. But it should start, right?

The vehicle has about 50 hours run time on it, with no previous problems. It was taken to a paint shop, where it has sat for 3 months. Now it will not start.

Did an ECU Live event with Hutter Performance, in Chardon, OH. They did not see anything wrong with the ECU. Hutter has never seen anything like this before.

Any ideas on what the problem might be?

Onbusy

iTrader: (4)

Well, you only need 3 things for it to fire - spark, fuel, and air. If you're sure you have spark and fuel, it's hard to believe you don't have enough air to make it fire.

Usually what I do if I'm completely stumped is shoot some starting fluid in the intake while it's cranking (hold throttle cable open at the throttle body with your thumb and release as soon as it fires). If it doesn't fire with that, you have a spark issue.

With it sitting, my first guess would be something with the fuel system - clogged filter, clogged injector, bad fuel.

DualQuadDave

iTrader: (6)

The fact that went to a paint shop is the direct problem. I have idea how they do it, but painters fubar every engine they touch. Have seen it so many times it needs its own meme. Did they do any welding on vehicle when it was there? If so, guaranteed they didn't unplug anything. I am positive they ran the battery down over and over again. May have fried the ECU or sensor(s). When you plug into the ECU, see if it's reading crank/cam signals. If it is and it's not firing, look at the injector drivers. If it got major painted, look for bad grounds.

TXFlyGuy

We pulled one spark plug and tested for spark. Sure enough, we have spark. The fuel is 100 Octane, and it is not contaminated or bad. I know we have fuel flow because I could smell the odor of raw fuel coming out of the exhaust.

TXFlyGuy

The ECU is good. We installed brand new batteries, and a new starter.

Going to direct jump the starter next visit, and see if that helps. It cranks slow now, much slower than before.

gametech

iTrader: (1)

Cranking much slower with a new starter and battery is a huge red flag. Pretty much guaranteed some wire connections (probably grounds) were disconnected and then bolted back over paint.

LilJayV10

iTrader: (39)

Yup!.

I'm not familiar with Motec, but if it needs to see a certain cranking RPM before it will start and it's cranking over slower than before...

Personally, I'd unbolt every ground and use a file or something to take any paint off.