1996 Suburban 454 Never Ending Issues

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Tom P

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I swear its a disease with these trucks. You fix one issue and 2 more pop up.
 

BowtieBrody

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I swear its a disease with these trucks. You fix one issue and 2 more pop up.

That's why I've got a bad habit of replacing **** that doesn't need it; I'll replace on component and I think "Might as well fix that before I need to." That's what led to me having injectors, FPR, upper and lower intake gaskets, fresh cap and rotor, coolant flush and a new thermostat less than a month after I got my truck!

Front end is going to be the same way, starting with the bushings on everything, the balljoints and shocks for now, eventually every steering component will be replaced too;
 

wheelman

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I think that's just the nature of a 20 year old truck.
When I bought my 1996 express can in 2005 thought I got a good deal.then water pump went.ac unit went.then dealer installed rebuilt.trans that new owners had installed.went out.then fuel pump.a electronic part.now engine is cranking and running.but dies out.i had to install a factory crab cap.after market cap skipped around.
 

SierraDully

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Yeah it's all in how the truck lived it's life. There's 1988 obs trucks that are high mileage and run great and 1999 obs identical trucks which are low mileage and junk.
I have found over the years that it's so important how it was taken care of, how it was used, and the maintenance that's been done.
I once bought a Tahoe off a young guy who owned it for 6 years and it's how he learned to work on cars. A wax-paper Pepsi cup was cut up and used for a thermostat gasket. That didn't work out well. He told me stories about pulling a 27' loaded travel trailer thru the mountains weekly and the truck struggling on every hill. He bought the wrong battery and changed it from side to top post but nothing was right. Electrical tape everywhere. The alternator was hooked up by slipping the alternator wire between the battery post and the cable clamp. I didn't notice it until it fell out on the highway one day.
I've noticed that if the truck has its original spare tire underneath the back end, it's an good indicator that it's been looked after.
The trucks with a worn out bald tire underneath for a spare because the owner was broke and used the spare as a permanent driving tire, I look out for those ones.
And before anyone points out how stupid what I just said about the spare tire is, just try it next time you look at one. It's not a hard and fast rule but it has actually been true for at least 4 trucks I've owned.

OP:I'm curious, when you had it running as good as it got, did it run like other 454's you've driven? Was it like a 454 that wanted to take off like a rocket or did it kind of seem like it was on life support even on its best days?
I once had a similar problem. Turned out the owner had swapped a 4l60e trans out and put in a 4l80e but didn't tune the ecm and it ran like total crap. Are your motor and trans original to the truck or has the computer been replaced? A mismatched part can cause ghosts like you're describing. Not likely but possible.
 

Tom P

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I think that's just the nature of a 20 year old truck.

You are absolutely correct, and I'm a sucker for a project.

And regarding SierraDully's theory on the spare tire, I would say he has a good point. I've noticed it on several vehicles I've owned in the past. The best case scenario being my wife's Denali. I should have known better because my Dually's spare is gone and the hanger is rusted all to crap. Hopefully before next spring's towing season I'll get a chance to pull the bed off and do some rust mitigation.
 

RedChevy44

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The gremlins strike again!

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I was towing a trailer up a hill and the engine stumbled for a second. I got my phone out and about a minute later caught the tach going crazy for a few seconds before the engine died.

OP:I'm curious, when you had it running as good as it got, did it run like other 454's you've driven? Was it like a 454 that wanted to take off like a rocket or did it kind of seem like it was on life support even on its best days?
I once had a similar problem. Turned out the owner had swapped a 4l60e trans out and put in a 4l80e but didn't tune the ecm and it ran like total crap. Are your motor and trans original to the truck or has the computer been replaced? A mismatched part can cause ghosts like you're describing. Not likely but possible.

This is the first and only 454 I have ever driven/worked on. When it is running it runs good. I feel like the new fuel pump made the throttle response crisper and gave it a little more power. I can't tell you how it runs compared to other 454s, but I can tell you that when it is running it tows 10K pretty good, and this is coming from a diesel guy.

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RedChevy44

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Speaking of spare tires, I had to use mine. The tread on it looked really good. Guess I'm the exception to that rule, haha.
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But the good news is I figured out why my tach went crazy. The connector for the crank sensor was bad. I crawled under there while the engine was running rough and wiggled it. If I wiggled it one way it would start to purr and if I wiggled it the other way I could kill the engine. I installed the new connector harness I had ordered and have put around 600 miles on it without a single hiccup. Dare I say that I'm finally starting to put some trust in it?
 

Tom P

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Dare I say that I'm finally starting to put some trust in it?

That would be awesome if you were on the verge of smoothing out all the kinks. I’m very nearly there myself. On my way home from work a couple days ago she started stumbling during any type of load. Popped the hood and didn’t see anything unusual. Long story short after research and testing it was just a grounded out spark plug wire....again. Tucked it all back up where it belongs and she’s back to purring like a kitten. Once you get the gremlins beaten out of these things they are fantastic rigs. I love my truck and hopefully yours becomes reliable to you.
 
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