po455 from rough start to no start, to start after 20 min

[weather]

Drove about 80 miles, stopped at bank, tried to restart, but had to crank several times to get it going, then drove it to oreilys and parked it. Then tried to restart it seconds after and it wouldn't restart. Then we pulled up code PO455 gross leak. After 20 minutes of letting it sit, it started up, drove it home, then restarts ok.
Last week changed out the purge valve on the exhaust manifold, service engine soon light came back on..... anyone know what these symptoms point to?

[97cargocrawler]

I think you mean purge valve on the intake manifold? Anyway, there's one back on the charcoal canister too you might wanna look at.

[TurnNburn]

anyone know what these symptoms point to?

A leak in your evap system? Going to need to hook up a smoke machine to isolate it further.

[weather]

Man, was that the easiest fix. Popped the hood, saw the small hose off the maf. Put a clamp on it, done! Just disconnected the battery, waiting about 15 min, reconnect to clear codes.
Got it back last week from an engine swap. I guess they missed a clamp on it or thought it would hold without one.
Started up and engine way more calm and smooth. Must have been riding around for some time like that. Heard hissing noise under hood, so maybe that's what it was all along.

[weather]

Thru this, I learned you don't need a smoke machine to test for an evap leak. You can simply get a cigar or vape and blow smoke into the system to see where a leak is. Can also light up a cigar or cigarette and use some tin foil and a hose and run any kind of not too pressurized air blower in....youtube vids all over on it.

[97cargocrawler]

Hey! The old look under the hood trick!

[weather]

So now won't start again, after hose is on. This is the 2nd day of this problem....gonna let it sit for some time and see if it will start back up, like yesterday.....I think it's a furl issue, maybe fuel pressure regulator. That's located on top of the gas tank, no?

[97cargocrawler]

Well hopefully you can unfurl this convoluted problem soon. The fuel pressure regulator is attached to the spider under the plastic intake manifold. If it leaks it will definitely create a hard start issue, not sure about 20 minutes worth of leaking between starts though.

[weather]

So it appears ive had multi problems. I bought a ICM, ignition control module. Gonna switch out tomorrow and see if that's my hot start problem. Then go from there. O'Reilly mechanic said that's the problem with warm engine no starts 90% of the time.

[weather]

After about $230 of replacing parts, I think it's fixed, but it wasn't any of the parts I replaced accept the last one. It was quite simple actually. After replacing, the vent solenoid, the purge solenoid, the evap canister and fuel pressure sensor by lowering the gas tank, and thrn replacing the coil, I'm happy to announce, and feeling quite stupid, that all that was needed was a new fuel filter.
You see, the old fuel filter was hindering gas flow and putting stress on the fuel pump. I decided last night, I was going to oreillys to borrow their fuel pressure gauge and buy a cheap fuel filter to see what kind of fuel pressure I could get before and after the fuel filter swap. Despite their gauge being off, before filter change out, was measuring about 72 psi. After change our was measuring 78 psi. It was a noticable difference! Drove it home and let it heat sink and it started right up. Will need to take it out for another harder and longer test, but this looks like it solved my problemo!