1996 Chevy C1500 silverado 5.7l vortec engine 2wd CRANK NO START ISSUE.

Ok following that logic, I did install new cats with the new engine but kept old muffler, I also pulled the distributor to check for any damage reinstalled it and after several cranking cycles reset engine at TDC and checked rotor placement and it was pointing at #1 cyl, however my mind keeps going to the timing thought. I will check compression as soon as I can. And keep ya'll posted. Thanks for your input.

Just remember though, when the rotor is pointing to the #1 cylinder, it could still be 180 degrees out on its exhaust stroke. #1 cylinder needs to be at the top of its Compression stroke. Use the spark plug out and the thumb bump test to verify its the compression stroke.

Weycraze,
Following along with your thoughts, First yes engine had been running fine, no misfires, no codes, and I had been watching fuel trims and the trims were good. I started truck one morning as I always did and went back in to finish my coffee came back out and truck had shut off, we t to restart and that is were we are now., my initial thought was timing engine seem to crank like it was out of time. I popped the dist cap off and crank engine over and rotor was spinning as it should. Check spark and fuel. Then I pulled dist to check gear and any other damage. Change rotor and cap, swap both cam and crank sensors I had all this on hand so why not.. then we got into more in depth testing. I spot check for compression and (YES the PLUGs were wet.). I have confirmed good continuous spark. I have confirmed all 8 injectors are opening and closing, and we have good fuel pressure. (New Delphi fuel pump) pressure on other was around 55psi and fuel gauge was off, cheaper aftermarket, that's why I chose to swap it out. Its sounding more like a flooded engine in which case I would like to know what caused that. My school of thought on timing and compression is while both are possible, very unlikely being this is a new engine. But I will do a full compression test ASAP. and recheck timing issue. It has taken me nearly a year to get this thing back on the road, after engine install I had issues with tranny, so installed reman. While working on all of this when I could, We had a visit from Hurricane Michael, that brought all the work on the truck to a halt. We are still digging out from Michael down here. Good news is if this turns out to be a internal engine issue it has a warranty. I will keep ya'll posted, and thanks for all the help.

One other thing I completely forgot to mention. I did have a (in my opinion). a high idle condition on start up, it would idle up to about 1700 to 1800 rpms for a few seconds. and then drop back down to around 700. cam retard was at -2 by the way.. this was always on a cold start by the way.

If the plugs were wet with fuel then you’ve probably got a flooded engine. Cylinder wash could be causing compression problems. Clear flood crank. Don’t crank longer than 15 seconds and wait 2 minutes between cranks so you don’t burn out the starter. If this is the cause, The next step would be finding why it happened. Stuck open injector, fuel pressure regulator.

Question
What does your ECT and what does your MAP read?

I had peluim off yesterday, I check for any leaks found none. Which I was really not expecting to has fuel pressure would hold at around 55 psi for more then 10 minutes after initial drop from 61 psi.. I also pulled and check each individual injector to see if any were stuck open, none were. I then check to see if each injector was spraying fuel as they should. All 8 seem to be functioning normally. This confirmed my test for 12v and pulse signal with a test lite. As for Map and ECT I have no readings.

If you can’t pull live data to read ECT and MAP then unplug each sensor and see what happens. This should cause the ECU to default to substituted values.
I would still do clear flood crank first since you’re plugs were wet with fuel.

Flooded engine can be injectors or fuel pressure regulator. It can be stuck open causing too high of pressure or could be the diaphragm busted.

just a thought could have lost its code for the keys immobiliser fault perhaps

Rusty, that’s a good train of thought.
I believe that vats responds by killing the injectors so I don’t believe he would be getting injector pulse and I also think that it will not crank the starter.

Don’t assume that this information is correct I’ll have to double check. Just from what I think I remember

Not sure I follow you on this one. More info please.

I will try that, Also see what reading I get with live data. I fully understand the flood concept, just not seeing any leaks to suggest such. Unless some degree caused an injector to hang open for awhile and it work it's way out. Perhaps when I getting running I can be around truck if it does it again. Here something. See something. That kinda of thing.

The reason I suggest it was I had a similar issue about 10 years ago car was running stopped by itself and ended up transponder aerial failed car cranked but wouldn't start.its just a possibility when everything else is turning no positive results.

Ok Thanks.

Ok Everyone, I believe with everyone's help we have most likely determine the cause of the crank no start issue. Which as some have suggested is indeed a flooded engine. I check the oil on the dipstick and determine 2 things, oil level is higher the it should be ( I check oil regularly) and it smells more like gas then oil. I will drain oil this evening. I know most likely cause is a leaking injector system, regulator or crack line etc. Or a injector that is stuck open. I could fine no such culprit when I had the peluim off. So here is my thought ( something is telling the fuel delivery system to deliver too much fuel. BAD 02, VACUUM LEAK, FAULTY ECM. Just some thoughts. Fuel trims were good before all of this. All of the 02 sensors are new, new cats, I have had no codes to suggest any problem with fuel/ mixture. By the way the manner in which I checked the spider injector system with peluim off. Was first I confirmed 12v and pulse with test light from the harness connector. Plug it in and pressurize the system, (Coil and ICM disabled). Checked pressure 61 psi, checked for leak with gauge held at just under 55 for more the 5 min. Had helper crank over engine saw no leaks. Pulled each injector to check for a open injector and to confirm each was spraying as the should. So I will drain oil and throw new plugs in and then check compression and if all good try to get it running and try to get some live data. Any other thoughts or suggestions.

Recheck spark make sure it jumps a good inch or so. To clear a bad flood pull all the plugs, unplug the coil pull the fuel pump relay/fuse. Charge the battery to get a fast starter spin. Then hold the pedal to the floor and crank it several times. Wait 20 mins or so before installing new plugs to let the remaining fuel in the cylinders evaporate. Earlier u mentioned cam retard. The pcm determines this when the rpms are over 2k. So it's not relevant to a no start. Also, check the fuel quality. Disconnect a fuel line and run the pump while the line is in a clear bottle. Check for water or discoloration of the fuel. Btw if it cranks and has injector pulse its definitely not a security issue.

Will do, I will have to set cam retard after I get it running, pulled dist to check for damage to gear, no big deal there though. Wasn't thinking of a flood issue to start with. Thanks I will keep all posted.

Good Morning Everyone. Just wanted to jump back in here and update my situation with my crank no start issue. I am still having a crank no start problem. We have spark. Fuel, air. Engine was flooded causing cylinder wash, believe this was due to constant attempts to start engine. Cleared that change oil still no joy. I have confirmed spark, working coil, ICM, etc. Fuel pressure is 61psi holds at 55 psi for 10 min or more. Currently I am recovering from rotator cuff surgery and can't work on the thing. Just thought I would update the post and see if anyone had a thought on the thing, Thanks

Hi simperfi/everyone,

Some guys have suggested crank it with the gas pedal on the floor (with everything dry). Any change?

At start, pcm focuses on ECT and MAP/MAF. If pcm is seeing a cold engine, the pulse width could be 6 or 7 times wider than when hot. What were your ECT and MAP/MAF readings?

I read through this and a few things stand out. One is that you said is sounded kind of weird like it might be out of time on the attempt to restart it. Second that there is fuel and the oil smelled of gas and was higher than it should be. I am thinking you have valves not opening for some reason. I would think snapped cam but you are getting the distributor turning though. I would go with some type of a valve train issue, we have valve that are not opening and or closing at all or at the correct time. It is important to understand you could have a stuck valve and get normal compression readings, but it wouldn't run.

First, Verify compression on each cylinder. Second, turn engine slowly with plugs out and verify that each cylinder has a compression stroke in the firing order. A lot of times I use my Lyle Valve Spring changer air hose (but a compression tester hose with the valve core removed will work too). Tape a rubber glove on it screw it into each hole. It will blow up the glove on the compression stroke, then when the exhaust valve opens it releases the glove and will not re-inflate it, then on the intake stroke it sucks the glove in. Make sure you have this in each cylinder. You need to verify you have all 4 strokes in each hole in the right order.

I will try and hook scanner up tonight and get the readings for MAP/MAF AND ECT THIS EVENING, AND GET THEM POSTED. THANKS