The Official Vortec 454 Info thread

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BNielsen

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Okay, so I've got a camping trip coming up and I'm making a run down list of parts I'd like to replace;
At the minimum - a decent tune up; cap/rotor/coil + icm/plug wires/plugs, oil change O2 sensors, fuel filter, etc etc etc ;
At the maximum - all new dizzy + full tune up, finally get the new 28# injectors in, replace the FPR, and a few new sensors and senders like the oil pressure, MAP, any sensor that's a pain to get to while the engine is together.

Anyone got anything else I should check? It'll be a 3/3 and a half hour trip pulling my 6500# camper. I'm hoping if I can get everything dialed up my truck should just stroll along at 60/65 with the camper.
As it sits now, the truck pulls the camper but starting off is a bear, improper fuel pressure is killing the take off, and worn ignition components isn't letting it pull as hard as it should. After about 45 minutes of driving it'll start to misfire, if I stop and let it cool down it's good for another 45 minutes. Cap and rotor maybe?
I'm just trying to get all my ducks in a row, this will be the longest trip pulling a trailer I've ever done in this truck.
 

92GMCK2500

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Do it all. You'll enjoy your time away so much more. We work hard enough as it is. Make your camping trip 'a camping trip', not a truck stress trip. Been there, done that! Cheers
 

454cid

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Okay, so I've got a camping trip coming up and I'm making a run down list of parts I'd like to replace;
At the minimum - a decent tune up; cap/rotor/coil + icm/plug wires/plugs, oil change O2 sensors, fuel filter, etc etc etc ;

Why would you mess with the ICM and 02 sensors if they're working? (Maybe check the voltage readings on the 02's to get an idea on how they stand?)

If you did anything with the ICM, I'd suggest maybe changing the screws out to something easier to work with than the stock screws that have thin heads, and maybe carry a spare ICM. I intend to swap my screws out to allen head, I've fiddled with the stock screws enough. Although, I wonder now if I could find a thumb screw in the right thread.

I also would not replace the factory coil unless you know it's bad.

How are your coolant hoses? If those are getting older, I'd be more inclined to worry about those. Maybe flush the cooling system if it's been awhile.

Clean your MAF?

How are your valve cover gaskets? Even the silicone gaskets get hard and leak given enough time.

Drivetrain oil if it hasn't been done in awhile?... T-case/axles/transmission.

Chassis lube?

Wash the truck, and clean the engine compartment. A clean truck is always better for traveling.
 

BNielsen

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Why would you mess with the ICM and 02 sensors if they're working? (Maybe check the voltage readings on the 02's to get an idea on how they stand?)

If you did anything with the ICM, I'd suggest maybe changing the screws out to something easier to work with than the stock screws that have thin heads, and maybe carry a spare ICM. I intend to swap my screws out to allen head, I've fiddled with the stock screws enough. Although, I wonder now if I could find a thumb screw in the right thread.

I also would not replace the factory coil unless you know it's bad.

How are your coolant hoses? If those are getting older, I'd be more inclined to worry about those. Maybe flush the cooling system if it's been awhile.

Clean your MAF?

How are your valve cover gaskets? Even the silicone gaskets get hard and leak given enough time.

Drivetrain oil if it hasn't been done in awhile?... T-case/axles/transmission.

Chassis lube?

Wash the truck, and clean the engine compartment. A clean truck is always better for traveling.
Parts like the coil/ICM, O2 sensors, and dizzy shaft are original, and with the truck nearing 200K and 26 years old I figured it was probably better to replace them sooner than later. Coolant hoses are good, they're both only about 3 or 4 years old, and I was planning on a coolant flush and a good inspection of the radiator.
Valve cover gaskets are dry, some seepage around the PCV valve but nothing that seems to be too out of the ordinary.
Drivetrain fluids are definitely on the list as well, everything is original so it's past time to change them out.

And the truck is gonna get a full scrub down and detail before the trip, since it's going to be warming up and I've finally acquired a good pressure washer and a good shop vac, I'll be able to keep on top of keeping my truck clean.
 

454cid

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Parts like the coil/ICM, O2 sensors, and dizzy shaft are original, and with the truck nearing 200K and 26 years old I figured it was probably better to replace them sooner than later.

Mine is almost 300K miles on the original coil. The problem is that replacements may not be as good as the orginal, same with the ICM. Shurkey has posted some detailed testing for the coil, that you might try. I don't have the original ICM anymore, but the first two replacements only lasted about a year. That's why I decided to buy another one, to have on hand. Since I haven't been driving the truck, I haven't actually swapped out the screws and put the spare in the glove box yet. My aim is to have another ICM and the wrench needed to change it with me, if I need it.

Coolant hoses are good, they're both only about 3 or 4 years old, and I was planning on a coolant flush and a good inspection of the radiator.
Valve cover gaskets are dry, some seepage around the PCV valve but nothing that seems to be too out of the ordinary.
Drivetrain fluids are definitely on the list as well, everything is original so it's past time to change them out.

A few years ago, I got a new GM PCV grommet on ebay. The original wasn't awful, but it wasn't holding the valve as well as I'd like with the bulk hose I put on it (OEM molded is NLA for the 454).

If you don't have one of the pumps that will scew onto your oil bottle, get one.... works great for the T-case and differentials.

I'm finally going to do my valve cover gaskets soon, as I've got some time off work coming up. They leak terribly, now.

And the truck is gonna get a full scrub down and detail before the trip, since it's going to be warming up and I've finally acquired a good pressure washer and a good shop vac, I'll be able to keep on top of keeping my truck clean.

Awesome. I've had an old electric pressure washer that I was given, and I've borrowed a gas, but I want to buy a new electric. I like the electric for smaller jobs, and the one I have leaks oil. I've been kinda thinking about a new shop vac too.

Battery connections? Grounds? Hows the battery itself? If it's getting older, maybe replace it, since you don't want it to decided to poop out on vacation.
 

Carlaisle

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You'll need to tune for those 28 lb injectors. When inspecting the radiator don't just look inside it - look at the fins, too. I've seen more radiators clogged from the outside than inside. I'll echo the comment on new parts potentially being of poorer quality than original. Check your new plug wires before installation. I received two brand new sets with multiple dead wires straight out of the box. Have you diagnosed the cause of your improper fuel pressure? The filter and FPR may solve this but they aren't the only possibilities. Caps/rotors don't overheat so they are unlikely to be responsible for your misfire after 45 minutes. Module would be my first guess. Check that evil quick disconnect heater hose fitting in the intake manifold. I'd replace that on a vehicle straight off the assembly line, but I am admittedly biased. How are your brakes? A spare belt is always a good idea.
 

Erik the Awful

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Parts like the coil/ICM, O2 sensors, and dizzy shaft are original, and with the truck nearing 200K and 26 years old I figured it was probably better to replace them sooner than later.
I'll pile on here. Replace any sensors that are acting up, but don't replace ones that are working. You're more likely to introduce problems.
 

BNielsen

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You'll need to tune for those 28 lb injectors. When inspecting the radiator don't just look inside it - look at the fins, too. I've seen more radiators clogged from the outside than inside. I'll echo the comment on new parts potentially being of poorer quality than original. Check your new plug wires before installation. I received two brand new sets with multiple dead wires straight out of the box. Have you diagnosed the cause of your improper fuel pressure? The filter and FPR may solve this but they aren't the only possibilities. Caps/rotors don't overheat so they are unlikely to be responsible for your misfire after 45 minutes. Module would be my first guess. Check that evil quick disconnect heater hose fitting in the intake manifold. I'd replace that on a vehicle straight off the assembly line, but I am admittedly biased. How are your brakes? A spare belt is always a good idea.
I was planning on pulling the shroud off and inspecting the rad top to bottom, fuel filter is due for a change but I tested the fuel pressure after changing at determined it to be the FPR, also evident by the persistent hot start issue (I've got 5O Motorsports Blue Knights in it now)

Plug wires are JBA 8mm; I inspected them straight out of the box and they looked to be in perfect shape, and as far as the tune goes, I've got injector date saved ready to flash into my PCM, brakes are fair, I'll probably throw on a new set of pads depending on how they look; rotors would probably have to wait until after the trip (damn you GM and your inboard rotors). And what I meant by the cap overheating is the cap cross-firing due to wear, it's been close to 50K miles I've had it on, and from my experience with Vortecs that's about the life span of them.

Spare belt, a spare container of oil, and a tool box full of tools is always in the truck.
 
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