Just bought an '86 C20 Suburban

[suburble]

Hi, all. I'm new to this forum but have plenty of vehicular fixitude under my belt.

I just bought an '86 Suburban C20 with 454, 2wd auto. Low miles- just turned 100k, bought from the 2nd owner. I'm looking to use it to haul a flatbed car trailer from Arizona to Florida and back.

The PO swapped out the carb and cut most of the emissions lines before delivering it. The carb that's on it now is a Qudrajet, but I'm not sure it's rebuildable. The idle screws seem to be the wrong thread, and the female threads for the air cleaner stud are stripped. Also, the rear 2 bolts holding it on the intake manifold are missing, which I am sure is not helping with sealing.

I've already got a line on a rebuilt 800 cfm Quadrajet from an 87(?) that seems like a good bet- what I'm in need of is the diagram for all the vaccuum / emission hookups.

Does anybody have a link to the diagram for an '86 454 auto?

Also, does anybody know the stated R12 capacity for one of these bad boys with the rear AC units?

Thanks,
-Josh

 

[Old77]

I wanna see pics

 

[Jims86]

Hi, all. I'm new to this forum but have plenty of vehicular fixitude under my belt.

I just bought an '86 Suburban C20 with 454, 2wd auto. Low miles- just turned 100k, bought from the 2nd owner. I'm looking to use it to haul a flatbed car trailer from Arizona to Florida and back.

The PO swapped out the carb and cut most of the emissions lines before delivering it. The carb that's on it now is a Qudrajet, but I'm not sure it's rebuildable. The idle screws seem to be the wrong thread, and the female threads for the air cleaner stud are stripped. Also, the rear 2 bolts holding it on the intake manifold are missing, which I am sure is not helping with sealing.

I've already got a line on a rebuilt 800 cfm Quadrajet from an 87(?) that seems like a good bet- what I'm in need of is the diagram for all the vaccuum / emission hookups.

Does anybody have a link to the diagram for an '86 454 auto?

Also, does anybody know the stated R12 capacity for one of these bad boys with the rear AC units?

Thanks,
-Josh

Nice!
The only 800 cfm q jets were on late 60's HI Po cars, maybe a few early 70s.
87 and up trucks were TBI fuel injection, with the exception of some HD 1 tons, which still had computer controlled 750cfm carbs.
Your best bet is to rebuild your 750, and maybe find another base plate...if you mix screws are in fact cross threaded.

 

[Mr Clean]

from N.E. Texas!

 

[bucket]

Howdy! We have a thread around here with pictures of different emissions and vacuum labels. I know there's an '86 C20 454 in there too because I posted it. And there's a lot of emissions stuff too, there's two smog pumps (one for each bank).

 

[HotRodPC]

Welcome to GMSB, we provide plenty of pic hosting space for members, so pic ***** it up. Lets see some Burb Porn !!!

And your OEM Carb should have been the E carb with the TPS and A/F Mixture Solenoid for the CCC system. That's what my 86 454 had on it when I first got the truck. I ended getting a carb off of like an 79 305/350 truck bolted it on and one helluva difference it made in performance. I'm not saying that doing way with the Feedback carb is a good thing, I'm saying mine had issues and I swapped in what I had in the garage and it worked great. A 750CFM carb is a 750 carb whether it's on a 305/350 or a 454. I'd imagine my jetting is a little lean and I could get a bit more performance if I re jetted but nonetheless, it running fine, not fouling plugs or lean misfiring, so I'll leave well enough alone until I swap intake manifolds.

 

[suburble]

Here's a pic...

You must be registered for see images attach

I already have a repop grille on the way and I'm looking at a brush buster this weekend.

Need to get the AC sorted after the PO "helped" by stuffing a couple of extra cans of R134 into the system because "It was blowing cool, but not cold" right before I picked it up. It blew out the O-ring(s) at the back of the compressor as we were in the DMV parking lot.

Front brakes are dragging the wear indicators- I'm betting they have never been off the car. That's next on the list after sorting the carb and vacuum issues.

I'm happy with it even despite the issues from the PO "helping" because it's all there and it was all working before he monkeyed with it.


-Josh

 

[suburble]

Welcome to GMSB, we provide plenty of pic hosting space for members, so pic ***** it up. Lets see some Burb Porn !!!

And your OEM Carb should have been the E carb with the TPS and A/F Mixture Solenoid for the CCC system. That's what my 86 454 had on it when I first got the truck. I ended getting a carb off of like an 79 305/350 truck bolted it on and one helluva difference it made in performance. I'm not saying that doing way with the Feedback carb is a good thing, I'm saying mine had issues and I swapped in what I had in the garage and it worked great. A 750CFM carb is a 750 carb whether it's on a 305/350 or a 454. I'd imagine my jetting is a little lean and I could get a bit more performance if I re jetted but nonetheless, it running fine, not fouling plugs or lean misfiring, so I'll leave well enough alone until I swap intake manifolds.

Maybe there was a difference between early build / late build 1986? I didn't see any wiring or provisions for TPS or a mixture solenoid, and nothing looked hacked. I'll have to take another look at it tomorrow. Would it say something about the E-carb on the door sticker?

Thanks,
-Josh

 

[MrMarty51]

Welcome into the forum.

 

[89Suburban]

Cool Burb welcome

 

[suburble]

Howdy! We have a thread around here with pictures of different emissions and vacuum labels. I know there's an '86 C20 454 in there too because I posted it. And there's a lot of emissions stuff too, there's two smog pumps (one for each bank).

Yep, found it. Awesome, that's a big help.

-Josh

 

[kleedus]

the burb looks pretty good




I'm looking to use it to haul a flatbed car trailer from Arizona to Florida and back.

that is going to cost you a small fortune in gas

454 turbo 400 and I am thinking probably 4.10 gears keep your speed around 65 anything above that will burn way more fuel

 

[HotRodPC]

Maybe there was a difference between early build / late build 1986? I didn't see any wiring or provisions for TPS or a mixture solenoid, and nothing looked hacked. I'll have to take another look at it tomorrow. Would it say something about the E-carb on the door sticker?

Thanks,
-Josh

Now that I think about it, I think I had determined that carb that was on mine was not supposed to be there either, and there were no plugs for the E carb. I did have the ESC though. Eventually I ended swapping to one of those Pro Comp HEI cheap dizzies off of eBay and did away with the ESC.

 

[HotRodPC]

the burb looks pretty good




I'm looking to use it to haul a flatbed car trailer from Arizona to Florida and back.

that is going to cost you a small fortune in gas

454 turbo 400 and I am thinking probably 4.10 gears keep your speed around 65 anything above that will burn way more fuel

I've had my hands on 3 C20 Burbs in the last few years here locally, and all of them had 3.73's. 4.10's are certainly possible though.

 

[Jims86]

Now that I think about it, I think I had determined that carb that was on mine was not supposed to be there either, and there were no plugs for the E carb. I did have the ESC though. Eventually I ended swapping to one of those Pro Comp HEI cheap dizzies off of eBay and did away with the ESC.

The E carbs were mostley a california deal, the ESC was on all of them from 82 to 86, but even then on select models. A vehicle meant to have an E carb, wont have vac advance, but just a 4 wire pigtail for the ECM controlled timing. The ESc dizzys with the Vac advance were there to try to curb knock.