New (to me) big red Suburban

[zachammer85]

I finally found an incarnation of my dream vehicle last week at public auction, no less. Its a 1995 Chevy Suburban K2500 that includes: 7.4 TBI motor, 4L80E transmission, 241 transfer case, 4.10 gears front and rear, and seating for up to 9 people! I was looking for a square body one but up here in Alaska, they are literal rust buckets or priced way too high. A GMT 800 was also on my radar but they are hard to find in the 3/4 ton class. For the price I paid for this, its a steal. The previous owner wasn't the cleanest person ever clearly and didn't know much about engine maintenance either. Guess I got my work cut out for me. A 12 valve cummins or 6.0 LS swap is likely in this things future once the old 454 decides to die. I'll try to keep up with this thread as I perform upgrades, maintenance, and take it on trips.

Had it delivered May 16th and immediately went to work. Cleaned up the interior real good, ripped out most of the old carpet and plan to replace it all with vinyl floor. Topped off the coolant, changed the oil, plugs, wires, checked the rotor and cap, removed most of the interior behind the front seat and began the process of scrubbing, vacuuming, sanitizing, and brushing every nook/cranny/surface I could reach. It currently runs like it has a vacuum leak or something. I'm fairly certain its running rich. If anyone has any sound advice on how to get this thing running like a champ, I'm all ears.

More will be added as I go I'm sure.

Replace carpet with vinyl floor
Change fluids
Change plugs, wires, cap, etc.
Super clean entire interior
Change lots of sensors (this thing has almost 200k miles)
Replace exhaust after manifolds (rusty and possibly leaking)
Replace head unit with up to date one and change speakers
Replace driver's door panel (it was missing when i bought it)
Repair or replace multipurpose switch (turn signal stalk on steering wheel, apparently they go bad and make your brake lights or signals not work)
Replace cracked windshield
Put on 265/75/16 A/T tires + find a spare

 

[zachammer85]

Few more updates;

finished pulling out the rest of the interior that needs replaced or cleaned. Found a pretty decent sized hole in my driver's floor board. Just another thing to fix I suppose. Some more sensors and other misc. parts came in today, which will get put in once I get all the rest. Managed to get the cargo area vinyl flooring in and secured.

 

[SuburbanSasquatch]

Nice rig. For getting it running nice, I would change out the fuel pressure regulator in the TBI. The spring inside rusts away leaving you with a rich mixture.

 

[zachammer85]

Nice rig. For getting it running nice, I would change out the fuel pressure regulator in the TBI. The spring inside rusts away leaving you with a rich mixture.

Funny you mention that. I'm currently having issues with it running rich. I can't seem to find any info on a fuel pressure regulator for the tbi unit. Any info you can provide on that?

 

[SuburbanSasquatch]

The fuel pressure regulator is in the tbi body. Pretty easy to change just remove the screws from the top and replace the spring, diaphragm and gaskets. I circled the screws in the picture. There are 4 more On the bottom side for the diaphragm and spring that you can get after removing the cap from the tbi unit. The replacement parts can be sourced from any parts store.

 

[Sparksalot]

Good plan on the vinyl. I love having that in my Tahoe.

 

[zachammer85]

The fuel pressure regulator is in the tbi body. Pretty easy to change just remove the screws from the top and replace the spring, diaphragm and gaskets. I circled the screws in the picture. There are 4 more On the bottom side for the diaphragm and spring that you can get after removing the cap from the tbi unit. The replacement parts can be sourced from any parts store.
View attachment 156404

I was able to find that spring and associated pieces but everything in there looked fairly new and the spring had plenty of spring left in it. Put new connectors on the fuel injectors, new o2 sensor, coolant temp sensor, and idle air control valve. Still running rich. I get dark exhaust smoke if i give it throttle after a cold start. Running out of ideas on how to get this rich fuel mixture fixed.

Edit: Played around with the EGR a bit, not sure if i have a vacuum leak or not as spraying starting fluid all over the vacuum lines didn't affect anything. The line coming from the evap canister to the throttle body looks like someone pieced it together with small lengths of tubing to make it work. Not sure if that would affect anything. I let the truck run for about 15 minutes and it idled pretty well, the running rich smell mostly went away but now it smells like a bad cat or none at all on the exhaust. On the floor pan replacement, nobody online has any available for the driver's side until like July. Guess i'll be putting in a temporary fix until I can get the proper part for it. I'm open to ideas for that as well but right now my plan is to cut the weak rust bits out and 'sandwich' 2 pieces of sheet metal, one underneath and one on top of the floor, and use some gasket maker or something similar plus some flat head bolts to keep it together. I don't have metal work tools or welding stuff available otherwise I'd make a more permanent fix myself.

 

[Quper]

It always ends up being my egr valve. Lol Now I have the option to run corn free fuel it's gotten alot cleaner.

 

[SuburbanSasquatch]

Say your edit above. I was doing a little research and came up with this: The ECM is designed to run a rich mixture during a cold start. If the rich running goes away after a few minutes that might be normal. Could it be that someone punched out the cats as a "performance" modification? Your floorboard temporary fix sounds reasonable to me. Use body panel sealant instead of gasket maker.

 

[zachammer85]

Say your edit above. I was doing a little research and came up with this: The ECM is designed to run a rich mixture during a cold start. If the rich running goes away after a few minutes that might be normal. Could it be that someone punched out the cats as a "performance" modification? Your floorboard temporary fix sounds reasonable to me. Use body panel sealant instead of gasket maker.

That sounds like a reasonable thing. As for the cats, I don't know. I'll have to take a closer look but it doesn't affect drivability so far. There's certainly an exhaust leak though somewhere before the muffler. The floorboard fix came out good. Use rivets to attach it to the existing good sheet metal. Sprayed underbody coating on the bottom and sealed it up on the inside. It was a pain in the behind to do alone but got it done and it looks good too. Started getting the interior back in too. I'll post pics later.

 

[zachammer85]

Not a huge update but got some more work done on the interior. It's now fully drive-able and more clean and comfy to be in. Anyone interested in installing vinyl carpet yourself, I recommend doing it on a nice warm day so the vinyl conforms to your floor better. I'm still fighting it and even with adhesive, it doesn't stay down very well. Also replaced the multifunction/turn signal stalk. That was a PIA but it needed it. Turned out I was missing the hazard relay under the dash but now i got a nice clean turn signal thing at least. About another month and I should be able to take this thing out and about and not just little trips in town. Can't wait to fill up the gas tank

 

[zachammer85]

Got most of the interior back in this past weekend and finally took it a good shakedown run since its all legally drive-able now. A few things I learned; big blocks love oil and don't like to rev high, the steering and front suspension needs a lot of attention, and my a/c fan only works on high.

 

[zachammer85]

Not many updates lately. Been busy with work and fixing up the house. Also been chasing a dtc 36 (idle speed control actuator fault?) that I haven't been able to pin down for find any fixes on within the web. These TBI trucks are easy to diagnose when it comes to their issues but fixing the problems is a bit of trial and error still. Its still running rich, very rich at startup. Got some sooty looking fluid coming from the exhaust after startup, which I assume is moisture mixed with unburned fuel. Found out this truck doesn't have a catalytic converter at all and someone replaced the muffler at some point but didn't clamp it in very tight, hence my exhaust leak.

 

[Red Mountain]

Enjoying the thread and updates. Thanks!

 

[RickR]

Following.

 

[mface7]

Looking at a 1997 k2500 right now for my first build so super interested to see where you go with this!

 

[zachammer85]

Looking at a 1997 k2500 right now for my first build so super interested to see where you go with this!

They're pretty good vehicles. 1997 will have the more updated vortec motor which makes better power/torque and slightly better fuel economy. I'm sure there are other changes as well but I think that's the most significant. I've been daily driving mine now for a few weeks and other than some loose steering that I'll be fixing this weekend finally, its pretty great. It makes a really nice cruising vehicle believe it or not. I rarely get over 2000 RPMs and it just keeps going without much effort on my part.

 

[zachammer85]

Not many updates lately. Been driving the suburban about once a week to keep it fresh, plus its more enjoyable for cruising than my daily driver. Haven't fixed the sloppy steering yet, sounds like from others that it doesn't really go away. It doesn't cause me issues though. Changed the brake pads, fixed some rust areas, and got a set of fog lights coming for the winter here. I work nights in the winter months and what little daylight we get here during that time I'll be sleeping so extra light is needed. Found out my A/C compressor isn't engaging, likely due to low or no refrigerant. The fan only works on high up front, heat works great thankfully. Wiper motor seems to only have 2 speeds, slow and too fast. Radio antenna is either not hookup up or the head unit is broken. It currently has P-rated snow tires, I'm looking for a cheap set of LT all terrains locally. Also, if anyone has any experience with these TBI motors, I'm trying to get more fuel mileage out of it. I know its a big heavy SUV with a big, gas guzzling engine but I'll take what I can get. Currently averaging about 8mpg, with mostly city driving.

 

[Drmiller100]

Is the smoke on startup black or blue? I bet it is really blue and you are seeing weak valve guide seals. That is an old Chevy trick. Drive it
Advance distributor timing. The timing chain stretches and retards ignition timing. Find out the specs and set it 5 degrees advanced from there. If the starter struggles to turn it over when the engine is warm back it off a bit.
454 is a great engine but 10mpg is what you get.

 

[mface7]

They're pretty good vehicles. 1997 will have the more updated vortec motor which makes better power/torque and slightly better fuel economy. I'm sure there are other changes as well but I think that's the most significant. I've been daily driving mine now for a few weeks and other than some loose steering that I'll be fixing this weekend finally, its pretty great. It makes a really nice cruising vehicle believe it or not. I rarely get over 2000 RPMs and it just keeps going without much effort on my part.

I ended up getting a 1998 K2500 with 160K miles...have a build thread with a few updates:

"CHUCK" 1998 Chevy Suburban K2500 Build

Finally got my rig to get started, and he's a beast! Lovingly named after my wife's great uncle because he was an enormous (6'3", 370), rough-around-the-edges, outdoorsy lover of American horsepower, this boy's currently pretty much stock. Going to be using him to teach my 3 boys (14,12, 10)...

www.overlandbound.com