97 454 possible injector issues

[tanman_2006]

I have a 97 k3500 154k miles. New engine and reman trans at 150k. I have all of the codes addressed and none set. The truck is gut less and hard starting when warm which leads me to believe there is either and injector or spark issue.

Future plans are 0411 (blackbear tune), long tubes, and exhaust.

Any thoughts?

Am I wrong suspecting the injectors?

Where is the best place to buy injectors?

 

[454cid]

What happened to the original engine and transmission?

The 454 is known for leaking/bad injectors. Usually people buy new or used non-OEM injectors through ebay. Normally, I think they're Bosch. Some people buy used GM injectors from another application, but that can cause tuning issues sometimes. I have not changed mine yet, but assumed that's where my hard starts were coming from. However, this past summer I had to do my fuel pump again. I installed a new Denso pump and the truck starts great now. It's possible my injectors aren't perfect, but the new pump sure changed the way the truck starts.

 

[someotherguy]

Checking fuel pressure including under load would be where I would start. 58-62 psi is the spec for the Vortec big blocks. Due to injector design though they will start and run at extremely low pressure, just will be gutless. I had one that I yard-drove at 30 psi, just had to feather the pedal. They don't behave like Vortec small blocks with the poppet valve junk that won't even start once you get down into the low 50's.

I had another with injectors leaking so bad it was washing several of the intake runners clean, and the vacuum hose to the regulator was completely cracked, yet the truck would still pull a house down...so I don't know if I would put too much faith in your issue being injectors. Hmm looking back that was the same engine just in two different trucks. Obviously the second scenario was with a good fuel pump.

Richard

 

[tanman_2006]

What happened to the original engine and transmission?

The 454 is known for leaking/bad injectors. Usually people buy new or used non-OEM injectors through ebay. Normally, I think they're Bosch. Some people buy used GM injectors from another application, but that can cause tuning issues sometimes. I have not changed mine yet, but assumed that's where my hard starts were coming from. However, this past summer I had to do my fuel pump again. I installed a new Denso pump and the truck starts great now. It's possible my injectors aren't perfect, but the new pump sure changed the way the truck starts.

The PO said the cam had a lobe go flat from collapsed lifters according to his mechanic. He spent alot of money on it but it seems he skipped out or cut corners on a few of the small things it seems.

 

[tanman_2006]

I haven't checked the fuel psi, supposedly the pump was replaced with the engine as preventitive maintenance.

 

[tanman_2006]

So good injectors aren't necessary for a truck pulling a trailer everytime its driven?

 

[tanman_2006]

The truck starts great cold.

Shut it off and let it sit and hr and it starts like crap. Barely fires, sounds like it is about to die honestly.

 

[454cid]

The truck starts great cold.

Shut it off and let it sit and hr and it starts like crap. Barely fires, sounds like it is about to die honestly.

Start checking fuel pressure when you expect the above to happen.... connect the gauge before trying to start the truck, and try to put the gauge in the window so you can see what's going on.

 

[tanman_2006]

Know of any kits to put a fuel pai gauge in? Preferably one that works on an edge insight

 

[454cid]

Know of any kits to put a fuel pai gauge in? Preferably one that works on an edge insight

Just buy a regular fuel pressure gauge. Harbor Freight has one, but it's not the greatest. An autoparts store is probably your best bet. They may have a loaner you can borrow. You have a fuel pressure port right on the fuel rail to connect it.