Is my truck tired???

[Sweetwater 420]

We have a 1986 Chevy c-30 3+3 dually with a 454. When we are pulling our 23' bowrider boat I noticed that it really struggles to accelerate uphill.... It'll go from 65 mph down to 50-55 mph on a gradual incline..... Not sure if this is common or not.

As far as I know it is bone stock. Should I change anything to give it a bit more horsepower? The boat only weighs 5,000 with trailer..... Seems like it should have no problems pulling it.

Thanks!!

 

[crazy4offroad]

I would give it a tuneup, plug wires, plugs, cap & rotor, maybe try some lighter oil like 10w 30 and an oil filter change, air filter, fuel filter, then see how it acts. If that doesn't revive it some I would run a compression test and see if maybe you have a cylinder losing pressure. If that all checks out I would start looking at the transmission. Pull the dipstick and see what the fluid looks like. Bright red it's still good. Brown-ish you could guess the clutches are getting bad. Silver specks mixed in could be worn bushings and thrust washers. If it's high miles you may not want to change the fluid but you can strain the old fluid and change the filter if you dont want to get into the expense of a rebuild. Higher mileage transmissions tend to wipe out if you change the fluid.

 

[bucket]

Yep, a good start will be a fresh tune up with quality parts. Also, I've got two 454 trucks and both of them have inadequate stock fuel pumps, an upgrade won't hurt them at all.

And welcome! Your crew cab looks great!

 

[jake wells]

Give it a tune up and rebuild your carburetor. worn parts like a distributor or dirty carb can cause one to be sluggish

 

[HotRodPC]

Welcome to GMSB Milton. Nice looking truck for certain, so whatever the issue, of it normal it's sure worth looking into and getting corrected. To find out of it's tired, I'd do a compression test and see what you come up with. The tune has already been mentioned. If that's all good, I'd then check what gear ratio you have in rear end. My 454 struggles a little bit when towing a 18ft tandem axle trailer and a 3/4 ton Burb without a motor and trans, but I halfway expect it to with wussy wagon 3.21 gears. I'm talking down from 70mph to about 60mph on small or slight inclines for a 1/4 mile or so. I know it would do much better with 4.10's but I don't with it often, so I've left the 3.21's in it even though I have the stuff right now to swap to 3.73, 4.10 or 4.56 if I wanted to. As heavy as your truck is, and towing a boat, probably loaded down with people and gear, I'd say you might hope to have 4.10's in that one. IIRC, you have a Dana 70 in that rear end and again IIRC, 3.54, 3.73, 4.10 and 4.56 are available. Do you buy any chance still have the RPO code option sticker in the glove box? That's a good start, but someone could have swapped the gears out too.

 

[elstm3]

If the 454 has fairly high miles it could also have a streched timing chain and that could reduce the power. But IMHO if you go as far as to check it i would just replace it. They are not expensive just takes a couple gaskets and some time to take the front of the engine off.

 

[89Suburban]

Let's see a pic of that boat!!!

You must be registered for see images attach

Welcome aboard.

 

[Sweetwater 420]

Thanks guys!!!! I appreciate all the advice! A friend of mine and I are going to tune it up this weekend and see what happens...... I will keep you posted!!!! I just got a call from a wheel broker here in town about the replacing the center caps to the Alcoa's and he stated $70 a piece for the rear one's but is still looking for the fronts..... I may just look a little on ebay......

Here's a picture of the boat haha....

 

[Jims86]

Thanks guys!!!! I appreciate all the advice! A friend of mine and I are going to tune it up this weekend and see what happens...... I will keep you posted!!!! I just got a call from a wheel broker here in town about the replacing the center caps to the Alcoa's and he stated $70 a piece for the rear one's but is still looking for the fronts..... I may just look a little on ebay......

Here's a picture of the boat haha....

I would say do a compression check anyways...piece of mind. I do one every tune up.
Make sure you use AC Delco parts, and especially a Delco fuel filter in the carburetor.

 

[Sweetwater 420]

Yep, a good start will be a fresh tune up with quality parts. Also, I've got two 454 trucks and both of them have inadequate stock fuel pumps, an upgrade won't hurt them at all.

And welcome! Your crew cab looks great!

Which 454 do I have so I can order a good fuel pump???? Gen IV???

 

[HotRodPC]

Yep, Gen VI didn't start til 96. And I bet there is some arguement over that, but it's true. Generation IV went thru to 95.
So lets hear it !!!

 

[Sweetwater 420]

Yep, Gen VI didn't start til 96. And I bet there is some arguement over that, but it's true. Generation IV went thru to 95.
So lets hear it !!!

Is it a Gen IV or a Mark IV???? Thank you for all your help!!!!

 

[HotRodPC]

Is it a Gen IV or a Mark IV???? Thank you for all your help!!!!

Yes sir. Mark IV thru 95, and Mark VI started in 96 on the Vortec motors. Scratch the generation lingo, that is incorrect.

 

[Sweetwater 420]

Yes sir. Mark IV thru 95, and Mark VI started in 96 on the Vortec motors. Scratch the generation lingo, that is incorrect.

Thank you very much!!!! I'll keep you posted as to what we find!!! Hopefully it just needs a good tune up!!!

 

[HotRodPC]

Damn, Noone wants to argue with me about Mark IV, Mark V and Mark VI Big Blocks. Sumbish, I've been mistaken on a couple things lately, so I need to redeem myself.

Fuggers never wanna play when I can win !!!!