'95 Chevy 3500HD / 454, NO POWER.

Discussion in 'Trucks and Trailers' started by Jason Rose, Mar 22, 2009.

  1. Jason Rose

    Jason Rose LawnSite Fanatic
    Posts: 5,858

    Ok, my 3500HD I bought is totally gutless. By this I mean it can just BARELY pull my 20' lawn trailer (about 7,000 lbs) up even a slight incline, and if there's a head wind my top speed is about 45 to 50 mph. That's IF I can get it up to speed in a mile before I have to stop or turn. I've NEVER seen a truck with a big block that accelerated as slowly as this one does.

    Evidently I must be thinking about gearing all wrong, but if this truck is "geared for towing and hauling" shouldn't it jump when I hit the gas?? Shouldn't it have loads of low end power and torque for towing?? All I get out of it is sloooow acceleration and a sick whine from the engine as it's rapped up to 3,500 RPM's before it will shift. Yes, I'm generally towing in "3rd" (meaning it's not in overdrive). I understand that this is a 9,500 pound truck (empty weight), but for god's sake that 454, and with the gearing it *should* have, it should take off, especaially with no trailer...

    I had a friend check it out, he thought the timing may have been off, turns out it was, possibly, about 4 to 6 degrees advanced. We adjusted that, and it seemed to help a LITTLE. We can't set the base timing, as we can't locate the wire that should be coming out of the loom that runs behind the distributer. (Sorry, I'm not a mechanic, and I may have botched some of the termanolgy).

    The air filter is new.
    The plugs are like new.
    Checked for any sort of vacuum leaks, replaced PCV valve.
    Checked Idle air control. (was having a problem with it idiling fast).

    Am I expecting too much out of the truck? Can I get some opinions from others that own this same model of truck? I know there's a few at least on this site.
     
  2. tyler_mott85

    tyler_mott85 LawnSite Senior Member
    Posts: 582

    What year is it?

    If it's a TBI 454 the Distributor Advance wire you're looking for is against the firewall on the passenger side kind of by the A/C stuff. Should be two wires. One tan and one black. No point in checking the timing unless that is unplugged. The computer will put it right back to where it wants it to be.

    In the glove box you'll find all of those need 3-digit RPO codes. Copy all of them down and do some searching on the net and one of those codes will tell you what the rear-end is supposed to be. If someone changed it you'll have to jack up the truck and do some counting and stuff with how many times it take the drive shaft to go around for the tire to go around once.

    Good Luck!
     
  3. Jason Rose

    Jason Rose LawnSite Fanatic
    Posts: 5,858

    It's a 1995. Yes TBI. The only tan and black wires in that area I can find go to the light attached to the underside of the hood... My friend crawled around in there for 15 minutes looking, top and bottom and couldn't find anything...
     
  4. Jason Rose

    Jason Rose LawnSite Fanatic
    Posts: 5,858

    Found a site for the RPO codes: http://www.c2e.info/rpocodes/

    Here's what I have:

    4.63 rear axle
    Trans. 4 speed auto w/ electris controls H.D. (hydra-matic 4L80-E)
    Brakes- Hydro power 4 wheel disk
    Engine- 7.4L 1 TBI, VB.

    I had no idea it was 4 wheel disk brakes. I've not had the rear duals off myself, only the tire shop when they put the new rubber on. The brakes on this truck squeek HORRIBLE, but it's not a metallic squeak like the pads are worn. The front pads I've checked and they are in great shape. but that's not the problem here...
     
  5. Gravel Rat

    Gravel Rat LawnSite Fanatic
    Posts: 9,544

    The brakes on your truck maybe glazed so they make noise. You can have lots of meat on the pads but the brake pads are glazed over and provide little stopping power.

    As for power wise you may have a transmission that is slipping a 454 should have good power. I would have your transmission checked. The 4:63 gears are the best for the 454 you don't want any taller.
     
  6. Jason Rose

    Jason Rose LawnSite Fanatic
    Posts: 5,858

    The brakes work really well, for a 9500 pound truck, but you are probably right about them being glazed. This truck sat most of it's life, indoors, only 50K miles since '95. I bought it and put more miles on it in the last 3 months than it's seen in the last 2 years.

    Would the whine I'm hering possible be the tranny slipping? God I don't want to even think about trans. trouble!

    This truck was always inspected annually and always serviced at the local Chevy dealer, one would HOPE that if the tranny was crapping out they would have red flagged that. The guy I bought it from genuinely wanted this truck being 100% operational when he sold it, If the tranny was taking a crap he probably would have had it fixed first. (If he knew about it). Stupid automatic transmissions... :cry: But I would hate driving a standard around town all the time!
     
  7. Gravel Rat

    Gravel Rat LawnSite Fanatic
    Posts: 9,544

    Do the cheapest thing first, change the oil in the transmission that way you pull the pan off and see whats in it. If there is lots of metal shavings/chunks in the pan its time for a rebuild.
     
  8. tyler_mott85

    tyler_mott85 LawnSite Senior Member
    Posts: 582

    Go drive the truck and warm up the motor and tranny then put it in park on a level surface. Leave it running and check the tranny fluid. should be a bright red pink. If it's darker or smells burnt you need to get the tranny looked at.

    I didn't pick up on the squealing part in your first post. It could very well be low on fluid or need some tranny work. When you put the transmission in gear in the cab does it go into gear right away or is there a delay? If theres a delay its probably just low but i would check anyway to be safe.

    The squeal on the brakes could just be dust accumulating. I'm sure you'll get a lot of it since its such a heavy truck. I've never heard a school bus whose brakes didn't make noise while it was stopping :)

    It's dark now but I will try to remember to check for the tan and black wires on my truck tomorrow. I'm trying to remember back to when I had to check my timing. Ihose wires may have been under a black cover on the firewall, passenger side. I believe there are a couple black covers that hide some wiring stuff or some of the A/C components. I'm 99% sure that it should be on the passenger side up above the motor somewhere. I'll get back to you tho.

    good Luck!
     
  9. tyler_mott85

    tyler_mott85 LawnSite Senior Member
    Posts: 582

    Got you some pics of my truck. 93 TBI but it's the V6 so it could be different. I doubt it on TBI tho.

    First pic is just of the engine compartment on the passenger side to get your bearings. The black panel on the firewall comes off and behind it is wiring. It should be behind there. Mine was sticking out so it was easy to find.

    The second pic I'm pointing to the connector so you know what to look for. Just pull that wire apart before you turn the motor on. turn on the motor, check your timing, shut er down. plug that wire back in. And you're good to go!

    Good luck!

    03-23-09_1431.jpg

    03-23-09_1432.jpg
     
  10. Jason Rose

    Jason Rose LawnSite Fanatic
    Posts: 5,858

    Tyler, nice effort, but my truck is a 1 ton HD with a 454. This is NOT a standard truck and is not configured like a normal 1/2 ton. My truck does not have any of that that you pictured under the hood, by the a/c. There's no wiring there at all.

    My friend is basically a mechinic, and he knows there *should* be a wire there to unplug to set the base timing, but where it is, we don't know. I was hoping for some assistance from someone that actually owns another 3500HD like mine (gas) that might know what's up.

    As for the transmission, my fluid is full and super clean. I suspect it was recently flushed or changed. Like I said, it was always serviced at the dealership and they would do stuff like that on a routine basis, it's more money for them if they push stuff like that. The transmission goes into gear, both fwd. gears and reverse almost instantly when selected.

    My opinion is that the transmission is working fine, but this truck of the weight it is should have a 6 speed trans, not a 4. The power issues I still believe are the engine, but WHY is not clear to me.
     

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