How do i do a tune up? 1995 Chevrolet K2500HD 7.4l

[Cuckfield]

Hello all. I've done some research and maybe I'm not looking hard enough, but how do I tune up my 7.4 big block? Things such as spark plugs, wires, cap, rotor.

Basically, what is the process from start to finish, best order to do things in, and what are the best parts to buy from rockauto?

Thanks in advance.

 

[termite]

I tend to stick with ac delco plugs and wires (standard oe replacement) if i were to order from rock auto.

Dist cap and rotor, I'd probably go with the one below.

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Full disclosure, i just picked up plug wires for my 1995 7.4l from carquest/advanced auto. Distribtor as well that came with cap and rotor installed.

 

[454cid]

Different vehicles, but I've purchased several sets of united motor products plug wires.

 

[Komet]

Replace everything one piece at a time, and the order won't matter. If you don't want to think about it, AC Delco parts should always be good enough.

Download the factory service manual and read the maintenance section.

 

[someotherguy]

Different vehicles, but I've purchased several sets of united motor products plug wires.

I went United Motor Products with the "premium" cap, rotor, and wire set (#18855) for my '93 7.4... and AC Delco Platinum 1 plugs.

If they haven't been done in forever, you should consider fuel filter and air filter, too.

Another "if it's been forever/never" you might consider the coolant temperature sensor (CTS) in the intake manifold as it has a huge amount of control over your fuel mixture; they go bad gradually and cause the fuel mixture to run rich. AC Delco on this one, too.

Richard

 

[Cuckfield]

I went United Motor Products with the "premium" cap, rotor, and wire set (#18855) for my '93 7.4... and AC Delco Platinum 1 plugs.

If they haven't been done in forever, you should consider fuel filter and air filter, too.

Another "if it's been forever/never" you might consider the coolant temperature sensor (CTS) in the intake manifold as it has a huge amount of control over your fuel mixture; they go bad gradually and cause the fuel mixture to run rich. AC Delco on this one, too.

Richard

Thanks a lot for the info.
Did you gap them or just buy them pre-set for .45? The exact plugs you speak of seem to be gapped for .45 and apparently these 454s are meant to be ran at .35, but does that even make a difference?

What spot should I mark on the engine to make sure the timing gets set back right with the new distributor?

Also, what contact points should I apply dielectric grease to when I put everything back together? Cheers.

Many thanks for allowing me to ask my stupid questions.

 

[someotherguy]

I went with the out-of-box .045 gap. Generally you don't re-gap platinum/iridium/etc. plugs unless you have one of the really fancy gap tools; the simple tools most people think of will damage these plugs. I was concerned about the gap when I was ordering them and I can't recall what the label on my '93 calls for, but .045 seems to be fine. If they were gapped really wide, like .060, I might worry. Follow your gut on this, though, since it's your truck and not mine.

As far as timing, you're not replacing the distributor, you're just doing cap and rotor. No need to worry about the timing.

Dielectric grease, a small dab of it, wiped inside the boots at each end of the spark plug wires can help prevent corrosion at the contact.

Richard

 

[termite]

Got pulled away before i finished my response regarding order of operations. Others covered it as well or better than I would have.

 

[Cuckfield]

I went with the out-of-box .045 gap. Generally you don't re-gap platinum/iridium/etc. plugs unless you have one of the really fancy gap tools; the simple tools most people think of will damage these plugs. I was concerned about the gap when I was ordering them and I can't recall what the label on my '93 calls for, but .045 seems to be fine. If they were gapped really wide, like .060, I might worry. Follow your gut on this, though, since it's your truck and not mine.

As far as timing, you're not replacing the distributor, you're just doing cap and rotor. No need to worry about the timing.

Dielectric grease, a small dab of it, wiped inside the boots at each end of the spark plug wires can help prevent corrosion at the contact.

Richard

Duly noted.

 

[454cid]

I like to use an acid brush to apply the dielectric grease.