96 K2500 454 normal cold start, problems on hot start

Hello, I have a 96 k2500 burb with the 454. The issue is that the engine starts normally every time when cold, but if I come back to the truck while its still warm, the truck cranks but wont start. After the 1st attempt, it will start then stall immediately. Then its a struggle to get it to start. This happens every time the exact same way.

About the truck, Its mostly stock. I have replaced the entire ignition system with MSD components. Spark plugs look good and are fairly new (specific for MSD). New ignition control module, cap, rotor, wires etc. These issues started way before the upgrades and have gotten worse gradually.

Thanks in advance for your help!

Sounds like either the injectors or FPR; or both. They're both a common issues on Gen 6 454s.
Does it cough out a cloud of smoke once it does start?

Check fuel pressure. See how high it is, and how fast it bleeds down. I had a simialr issue for years and thought it was the injectors leaking. When the fuel pump became obvious it was giving up, I replaced it, and was surprised it fixed my "injector problem".

I used to have to prime the system before trying to start the truck. It would still need to be cranked twice. If restarting within about a 20-30 minutes it would easily restart.... wait a little too long, and it was terrible.

CHRIS OCHOA said:

Hello, I have a 96 k2500 burb with the 454. The issue is that the engine starts normally every time when cold, but if I come back to the truck while its still warm, the truck cranks but wont start. After the 1st attempt, it will start then stall immediately.

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I have a '97 K2500 with the 7.4L. Similar deal--starts fine cold, cranks a long time before starting when warm. Mine does not stall.

This issue is actually pretty-far down the priority list right now. Last time I tested fuel pressure, it was about 50 psi; which I guess is low. The fuel filter is so old I wonder if it's original--the flare nuts holding the fuel tubing to the filter are totally seized; replacing the filter is going to involve cutting the tubing, and then splicing fresh tube along with a fresh filter.

If there's another cause for this problem, I don't know it. At least...not yet.

CHRIS OCHOA said:

Spark plugs look good and are fairly new (specific for MSD).

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WHY do you need "specific" plugs for an MSD ignition? Seems very suspicious.

What info do you get from the data stream? How far off is the distributor/crank sensor alignment? Any codes? Anything else unusual in the fuel trims, coolant temp sensor...anything at all?