Crank but no start issue

[rjr]

My 2013 Equinox will not start after an engine rebuild. The timing chain guide had broken causing valve and piston collision. I replace all pistons and rings, all valves, ground in the valves, replaced timing chain and guides, new camshaft sprockets, new head gasket, new exhaust manifold (the old one had a crack), cleaned the existing fuel injectors, replaced other miscellaneous gaskets on all parts removed and reassembled. Now the car turns over just fine when turning the key. I get spark from the plugs and I have fuel pressure. I’ve checked and doubled checked to make sure I connected all electrical connections. It sounds like it wants to crank when turning over but it just won’t. What else am I missing? Any ideas are appreciated.

 

[Uluz2a6]

I assume this engine was rebuilt because of a catastrophic end? Jumped timing, valves vs pistons and the pistons won? That's why you replaced valves?

About 1 in 10 of the 2.4 engines we rebud out here also experience damage to one or both camshafts. The "snout" or keyway end gets spun several degrees when the failed engine came to its abrupt stop. So when you set the timing, it's actually off by several degrees.

A leak down test should be your next step.

This is all just guessing, as you claim you have correct fuel pressure at rail and spark.

You could disconnect your mass air sensor and see if it starts Ina "default strategy" but unlikely.

I assume you aren't near Las Vegas, or I could come help you

 

[rjr]

I assume this engine was rebuilt because of a catastrophic end? Jumped timing, valves vs pistons and the pistons won? That's why you replaced valves?

About 1 in 10 of the 2.4 engines we rebud out here also experience damage to one or both camshafts. The "snout" or keyway end gets spun several degrees when the failed engine came to its abrupt stop. So when you set the timing, it's actually off by several degrees.

A leak down test should be your next step.

This is all just guessing, as you claim you have correct fuel pressure at rail and spark.

You could disconnect your mass air sensor and see if it starts Ina "default strategy" but unlikely.

I assume you aren't near Las Vegas, or I could come help you

Thank you for the help. Yes, I had a catastrophic valve to piston collision while traveling around 80 mph due to a timing change guide breakage. After the rebuild I am getting right at 90psi across all 4 cylinders. I’ve opened the front cover and valve cover to reset the timing chain thinking that perhaps the chain may have jumped a tooth or 2 that could have caused valve opening prematurely before adequate compression can be reached, still no improvement. Considering the rpm and speed at the time of the event your suggestion about the cams sounds likely.

 

[Uluz2a6]

Compression test won't reveal culprit. Need to do a leak down to know for sure unless you have a known good camshaft(s) handy to compare

 

[rjr]

I did the leak down test on 4 different rotations of the crank at TDC to make sure it was at least once done on the compression stroke. It failed miserably every time. I even kept air pressure flowing while slowly turning the crank and never found a position where it held any pressure. New cams are on order.

 

[Uluz2a6]

The leak down test can be tricky on these engines because of the valve overlap. If you have already purchased the cams, remove the timing chain and actuators and verify the keyway(s) have spun by comparing to the new camshafts. It's likely only one has failed. Then you can return the other.

 

[rjr]

In your experience, do you see the damaged cam to be the intake or exhaust more often than the other? Curious because the cams I’ve ordered, one has been shipped but the other is on back order. Hoping I may get lucky to get the one that may fix the issue first and not have to wait on the back ordered one.

 

[Uluz2a6]

50/50 unfortunately.

Intake on national back order I think.

Send me a picture of the shouts oun both and I can compare them to known good ones I have if you like