P0171 _0136 long crank, low fuel pressure help

Hi, I am new here. I have some mechanical background.

I would appreciate any help on where to start with this. I have restored this truck about 3 years ago, lots of things have 60k miles or less (O2 sensors, Injectors, seals, Coils, Exhaust, Catalytic converters, Engine, etc.).

The truck is near 300 000 miles and quite clean.

I read many threads, I am thinking vaccuum leak or fuel pump?

How can I test those things without vaccuum equipment the simplest way?

Thanks.

 

YO
Welcome!

im not that ‘OEM only person’
But
After listening/reading here, I’m beginning to adjust my mindset

tht P0171…..I threw same…..after installing eBay injectors…..I was 90% sure that all other possible causes were not the issue.
Sent my old leaking OE injectors to Motorwest, installed….i was free and clear
That’s me
But
That P0136 points in another direction
What O2 sensor did u install?

 

I put Denso, all quality parts. I don't mind changing parts, but I am a bit in a hurry to fix this, I need to go back in the woods.

The 02 sensor looks alright, not cut wires, I changed it 2 years ago basically.

 

Me too as far as O2 sensor

the only other cause on both codes is exhaust leak (fuel?)

Another seasoned member advised me too look at header for cracks with heat shield removed

you said RR’d ‘…..injectors, seals…’
Seals you mean injector cups?

 

Well I bought a JDMengine 3 years ago, it was like new with all the stuff on it, so everything is top shape when it comes to injectors, coils, engine seals, etc.

I hear a little exhaust leak maybe some bolts are loose, I will check tomorrow, but I suspect something more.

Even my idle ain't good, the rpm was fluctuating on a cold start today and it takes way to long to start when I crank it.

 

that might just be the issue!
let everyone know once you investigate

 

The engine has poor acceleration so I can't drive it anymore.

Checked a couple things today :

- The MAF is as new, super clean inside, the seal looks perfect so the MAF seal aint the problem.

- There is a cracked hose attached to the air box with no clamps, I don't know its use I will fix this but it doesn't go directly to the throttle body, it goes on the left side of the engine bay to some sort of valve, relay?

- There is an exhaust leak in the gasket between the 2 cat (California version) and when I spray it with water the idle gets much better instantly, so I will fix that.

- Unplugged the back oxygen sensor, the engine pulled better but the smell tells me it runs lean a lot.

Where is the fuel filter located?

Thanks all, will keep posting.

 

Ugh
It’s a PITA
Under intake manifold



I RR’d FF b4 this pix taken
My hands were swollen from various things gaining access
Chain Mail gloves would be perfect