80 Series 1FZ-FE Hot Start Issues (1 Viewer)

[dboyes]

Looking for a little guidance on some hot starting issues. I drove my 80 across the country for college. While driving I noticed lots of built-up pressure in the gas tank when filling up. Gas would sputter out and the truck began to struggle to start while hot. I replaced the vapor canister expecting that was the problem however the issues continued. I also replaced the FPR which also did not fix the problem.
Right now when I start the truck hot it stalls. Then when I start it again it turns over longer than it should and then starts up a little rough. If I give the truck a little gas on hot start sometimes I can prevent it from stalling. The truck starts strong every time when cold.
2 side notes as far as engine codes go. I had a PO401 engine code during my drive out and replaced the EGR modulator but on long drives the engine code still pops on occasionally. Also while offroading for an extended period of time, driving slowly and building up heat, I got a PO171 engine code. I cleared the code and since then it hasn't come back. Not sure if the two issues are related. Looking for some direction, thinking of replacing fuel pump, cleaning the EGR valve, and insulating the fuel lines as fuel could be vaporizing in fuel lines.

 

[jonheld]

I'm going to guess torn intake plenum allowing unmetered air into the system.

 

[doc_random]

The 2nd character in both codes is a zero. Search P0171 on "this forum" and it brings up many hits.
Did replacing the charcoal cannister solve the rule tank pressure build up? It should have, You may have 2 or 3 separate issues.

January post suggestion oxygen sensors, part numbers listed:

Just bought a '96 Lexus LX450!

Hi everyone! My partner and I just purchased a 1996 Lexus LX450 about a week ago. It has just under 200k miles, and we're currently sorting it for some light off-roading, camping, and dog car duties. It came with an Ironman 4x4 front bumper and 2" lift... and that's about it. Cosmetically, it's...

forum.ih8mud.com

Some vehicles have rust issues that make changing O2 sensors harder than it should be.

This was from @Malleas in June:

Needing some help with P0171code.

I have had this code for a few months now, i can seem to clear it. So I have, cleaned MAF, replaced fuel filter, ran injector cleaner, seafoam, replaced hoses and gaskets and PCV, no leaks with a smoke test, and have replaced both o2 sensors with factory sensors. CAT was removed by PO, I also...

forum.ih8mud.com

First item is what @jonheld, air leaks after the Mass Airflow Meter (MAF) will cause a too lean air-fuel ratio. Could be a vacuum leak anywhere in the system.