454 Tune-up Question

It could also be your fuel pump relay not closing to turn the fuel pump on

Probably the fuel pressure regulator. My 97 7.4 has over 220,000 mi on it and it's not been annoying enough to hassle with. It still has the original injectors. If you want to check the fuel pump relay just switch it with one of the other relays with the same numbers on top.

Have you had to replace the intake manifold gasket yet. Keep a eye on the coolant level. When the coolant level under the radiator cap starts staying about the same level as the top front passenger side of the block this will be the likely culprit. Some leak externally where you can spot some coolant that's leaked.

Very good strong motor, wish they still made them. It's still hard to get used the high RPM's on these new small blocks for me.

Peg Leg wrote:
Probably the fuel pressure regulator. My 97 7.4 has over 220,000 mi on it and it's not been annoying enough to hassle with. It still has the original injectors. If you want to check the fuel pump relay just switch it with one of the other relays with the same numbers on top.

Have you had to replace the intake manifold gasket yet. Keep a eye on the coolant level. When the coolant level under the radiator cap starts staying about the same level as the top front passenger side of the block this will be the likely culprit. Some leak externally where you can spot some coolant that's leaked.

Very good strong motor, wish they still made them. It's still hard to get used the high RPM's on these new small blocks for me.

I'll try the relay swap you suggested, thanks. I do have to add coolant to it occasionally but I don't smell any coolant. Never have to add much, maybe just a qt. a couple times a year. I too like this engine. Plenty of grunt pulling my trailer over the mountains.

He he he... that is the CLASSIC 454 problem.

I have a 2000 K3500 pickup with the 454 engine. I have the same issue.
I've had my pressure regulator replaced - no help. The rest of the internet says its leaking injectors. I bought a set of replacement injectors online that wouldn't fit so I personally have decided to just deal with it. I find giving it a bit of gas when long cranking seems to help it.

In researching the issue, I bookmarked the following links. I think you'll find them useful:

http://www.chevytalk.org/fusionbb/showtopic.php?tid/257907
http://www.fullsizechevy.com/forum/general-discussion/technical-maintenance/354448-454-do-yourself-fuel-pressure-regulator-someone-help.html

Captain Obvious wrote:
He he he... that is the CLASSIC 454 problem.

I have a 2000 K3500 pickup with the 454 engine. I have the same issue.
I've had my pressure regulator replaced - no help. The rest of the internet says its leaking injectors. I bought a set of replacement injectors online that wouldn't fit so I personally have decided to just deal with it. I find giving it a bit of gas when long cranking seems to help it.

In researching the issue, I bookmarked the following links. I think you'll find them useful:

http://www.chevytalk.org/fusionbb/showtopic.php?tid/257907
http://www.fullsizechevy.com/forum/general-discussion/technical-maintenance/354448-454-do-yourself-fuel-pressure-regulator-someone-help.html

Hey Capt...so if I'm reading your post correctly you never did change the injectors? If that's true maybe I can find someone on here that did change them, for that reason, and see what their outcome was. I'm not that annoyed with the problem enough to just start throwing parts at it.

I think Pinellas Carburetor can test/clean/refurb your existing. They had a shop along Busch east of Nebraska (9203 N 14th St, Tampa (813) 930-8612). Might be worth a call, especially if there's an aftermarket won't fit problem.

j-d...thanks. I'll give them a shout and see what they say. I would also hope that if these are in fact the problem, I would hope that after 14 years someone made a better injector.

Its true - I didn't end up changing them. Life ended up getting way to busy around the time I found out the replacement injectors didn't fit, so I didn't have time to pursue them further.

I can't see how a injector would leak off pressure hot and then gain it before you start it cold. These are spot on for a cold start.

It is my understanding that when hot, they leak what fuel they have in them. When you go to start it, and fuel has leaked from them into the combustion chamber, the fuel-to-air ratio is wrong.

Its fine when cold because the extraneous fuel has evaporated.