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91 Suburban V2500 - Tow/Weekend Rig - Build Thread

Next recent mod was a heated o2 sensor. Since adding headers, i've replaced my o2 a few times, and kept having problems.

Finally took the plunge and got the delco AFS74 heated o2 sensor.

Ordered that and its plug from rock auto. Wiring is easy, but took some time. ALL the wire loom on the drivers side was trashed, so i re loomed it from the rear tire all the way into the engine compartment.

All i can say is WOW. It has totally made my high RPM under load stumble go away, AND seems to have improved my mileage. Drove from Pleasanton to Zephyr Cove in Tahoe on about 3/4 tank of gas, towing up the grade from sacramento.

Haven't calc'd it, but its definitely back in the reasonable range.

First time towing up the grade with my 4.10's, and after all the hassle that caused me, i'm glad it say that it tows significantly better. Doesn't get the job done any faster, but is able to hold speed and cruise a lot easier.

Now, need to get working on my cooling system. Since i've had it, ive done numerous water pumps, flushes, tstats, caps, etc. Its always gotten a little warm going up the grade, but its gotten worse. Saw 240ish on the way up when it was cool out, and about 250 today on the way back when it was 90-100 out.

Not good. Looking into a new radiator. Will update.

Overall, VERY pleased with its performance. This is a huge step, cause its been frustrating for a LONG time, and i'm glad that its doing its job again :)
 
apologies for the earlier posts (i went back and cleaned 'em up)

but when i installed trans cooler, i also upgraded to one of these (H1 Hummer fan. this one for V belt drive. there is also a serpentine belt drive model). it may help yours...

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apologies for the earlier posts (i went back and cleaned 'em up)

but when i installed trans cooler, i also upgraded to one of these (H1 Hummer fan. this one for V belt drive. there is also a serpentine belt drive model). it may help yours...


Interesting. Thanks for the suggestion. Looks like the newer Dmax fan.

My only concern is that it won't hold up to long, higher RPM pulls. I'll spin my motor at 3-4k for long grades, and the old diesel's, IIRC, never spun that fast.

Would hate to have a fan come apart on me.

I'll look into it though.
 
Next recent mod was a heated o2 sensor. Since adding headers, i've replaced my o2 a few times, and kept having problems.

Finally took the plunge and got the delco AFS74 heated o2 sensor.

Ordered that and its plug from rock auto. Wiring is easy, but took some time. ALL the wire loom on the drivers side was trashed, so i re loomed it from the rear tire all the way into the engine compartment.

All i can say is WOW. It has totally made my high RPM under load stumble go away, AND seems to have improved my mileage. Drove from Pleasanton to Zephyr Cove in Tahoe on about 3/4 tank of gas, towing up the grade from sacramento.

Haven't calc'd it, but its definitely back in the reasonable range.

First time towing up the grade with my 4.10's, and after all the hassle that caused me, i'm glad it say that it tows significantly better. Doesn't get the job done any faster, but is able to hold speed and cruise a lot easier.

Now, need to get working on my cooling system. Since i've had it, ive done numerous water pumps, flushes, tstats, caps, etc. Its always gotten a little warm going up the grade, but its gotten worse. Saw 240ish on the way up when it was cool out, and about 250 today on the way back when it was 90-100 out.

Not good. Looking into a new radiator. Will update.

Overall, VERY pleased with its performance. This is a huge step, cause its been frustrating for a LONG time, and i'm glad that its doing its job again :)


I have the heated O2 and plug sitting in my garage. Wow, I need to get this installed! Sounds like it helped a ton. This was a great post. Thanks!!!
 
I have the heated O2 and plug sitting in my garage. Wow, I need to get this installed! Sounds like it helped a ton. This was a great post. Thanks!!!


Ordered all new cooling stuff. New brass core/brass tank radiator, hoses, Delco water pump, staun rad cap, staun tstat.

Hoping the new radiator helps my current cooling issues. Never overheated, but definitely got into the 3/4 gauge range. And its been cruising on the freeway unloaded in the 220 range, so hopefully that all goes away.

The cooling stuff will take a few hrs when parts get here, but overall, I have a strange feeling of satisfaction in regards to how it did last weekend. Its been a while since its gone on a long trip, actually had to work hard, and got the job done effectively. Towing up to tahoe again on Friday, so hopefully the cooling system holds together for one more tow before the overhaul.

May finally step up to electric fans in the next couple months, but need to let the credit card cool down and quit smoking for a bit:haha:

Plus, i need tires before winter, and REALLY don't want to run 16.5's again....which requires new rims too :doah:

Scouring craigslist for the right deal.
 
F!ck me. It dies again.

Towed all the way to Tahoe, running better than ever.

Ran it down the hill (no boat, luckily) , up to 75 on the freeway. Make a couple stops, back on flat ground..... Stumbles and dies. Same symptoms as last time.

Won't restart. Ign wires are fine, cap/Rotor fine, dist tight. Sounds like its out of time. Swapped ign modules, no improvement. Wtf.

Waiting for Aaa..... Again
 
Pump primes. Cant see the gauge to check pressure while cranking, but can see fuel at the injectors

Definitely spark

Or timing chain.

Curious if is a coil

Did run it a bit hot towing Friday, but not bad.

Wtf
 
Oh, and I'm 102 miles from home. With 100 miles included towing. Should have let it roll farther....
 
Been commuting in it too. Been running fine.

Very frustrated. Hesitant to put a crate TBI motor in, as all the bolt ons seem to be what gives me trouble, and they wont be replaced. Wiring harness stays too, and it's seen better days.

May be time to bite the 6.0l bullet.... But don't have time to do a swap.
 
ignition module?

pickup coil?

they can both crap out for no damn reason when they get hot...:dunno:
 
ignition module?

pickup coil?

they can both crap out for no damn reason when they get hot...:dunno:


Changed the ign module on the side of the road, no change.

May be the pickup coil. But i would like to expect better from MSD, that is less than 6 months old.
 
Hate crap like that...

I'm sure you've checked, but stupid loose wire somewhere maybe? Just hoping its something simple...

Loose bat cable, coil wires came loose etc. Keep us posted
 
Hate crap like that...

I'm sure you've checked, but stupid loose wire somewhere maybe? Just hoping its something simple...

Loose bat cable, coil wires came loose etc. Keep us posted


Checked the coil wires, all good.

May be some sort of bat connection, but ALL accessories/dash/key on stuff work fine.

Going to check spark when i get home, but i'm fairly sure its spark related.
 
Was planning to tow up to tahoe this weekend, and have another trip planned in august.

Also have a little wheeling trip planned in 2 wks, and was supposed to take my rig.

Having a hard time relying on this thing, mentally, now that its left me stranded this many times :(

At what point do you just give up? If I end up with another truck (again), this one will ended up 90% retired....
 
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