My K5 Blazer Story.

[bmchevy1979]

On my 74 I had to use a vacuum bleeder at the wheels to get it to finally bleed correctly and it then would put your head in the windshield if you weren't careful but I had to remove the breeders and put some thread sealant on them to keep air from coming around them and giving me a false reading of air in the line I had tried a power bleeder on the master and got them to work but never were quite right until I tried the other bleeder
Fyi: it was my rear brakes as well and I had to keep pushing the button on the prop valve to get it to bleed

[Zoomad75]

I got a little bit done this morning. I went ahead and made the changes needed to have the Drac module read correctly with the tire size and gearing we have. I used the info found on this page http://tbichips.com/drac/ which was very helpful.

Here's the Drac module.


Here it is opened up. The straight jumpers are what need to be altered, here it is before.

Here it is after. I had to remove one jumper and add 3 more in different spots. We'll see if it's accurate or not!

[justcuz]

Looks good, sorry to hear the brakes are being a pain. I was going to suggest an adjustable valve from Summit or Jegs.
In the old days the guys would drill holes in the backing plates to keep the brakes cool and the early NASCAR drums had a bracket that practically exposed the entire rear of the braking assembly. That was for cooling on a race car.
Not so great on an off road vehicle where your big problem is water retention inside the drum. That was solved by drilling small holes in the drums between the cooling fins to let heat and water out.
Probably more trouble than it is worth, just some old tech and education.
Keep up the good work and posting up the progress.

[72MARIO]

Why did you choose to use a factory valve ? Any reason not to just remove the valve and replace with a adjustable one in the rear line only ? I am having problems with my 1990 suburbans valve. nearly positive its what is making my brake calipers stick on.

[DirtyLarry]

Originally Posted by 72MARIO

Why did you choose to use a factory valve ? Any reason not to just remove the valve and replace with a adjustable one in the rear line only ? I am having problems with my 1990 suburbans valve. nearly positive its what is making my brake calipers stick on.

Because I am not the kind of hack that would retrofit on some aftermarket tack on thing like an adjustable prop valve . Removing RWAL and retrofitting to the factory OEM design of 73-89 squares seemed like the clean and most logical way of going about removing RWAL. If you notice, I am not a big fan of aftermarket crap. If anybody ever saw this Blazer they would think the 5.3L and 8 lug axles were installed at the factory and it never had RWAL in its life.

[Zoomad75]

Keeping in line with the KISS principle. Stock in this case works. We don't need the ability to adjust the rear bias. Keeping it stock limited the plumbing changes we needed to make. One less thing to fail 60 miles off pavement.

Our problem was a master cylinder that wasn't pushing fluid to the rear. Even new parts can be crap right out of the box. So I had my local NAPA store warranty the master cylinder and we installed it tonight. Even the bench bleeding went quicker, less air. I borrowed a miti-vac from one of my techs and vacuum bled the rears. We got fluid back there finally. It's not perfect, but we'll revisit after we get it running and get a feel for it.

[Zoomad75]

Small progress report. Larry's kicking ass with the wiring. I swear he is getting better with every truck he's done. The wiring is turning out way cleaner and neatly routed than any UAW guy back in the day would have ever done. No pics as I'll let him take better shots than ones from a cell phone. It's just very tidy and tucked away blending into the background letting the engine be the focal point under the hood. He's got fresh battery cables and money for some fuel I dropped off tonight, so getting this thing lit off isn't far from happening. He's got more wiring to do, but should be done soon. Getting exciting.

[MTCK]

Exciting - getting close.

[DirtyLarry]

Wiring updates…

As with the Polar Bear 8.1L swap, I had to dig deep into the harness hord for GM proper connector and wire colors/size to keep the wiring GM logical. Any dumchit that knows GM logic could work on this rig 25 years down the road.


Bulk head wiring done. Working my way to the ECM and Fuel Pump relay


Got the MEFI-4 ECM mounted snugly under the dash. MEFI ECM’s are funny in that there are only a 2 power wires (key on and constant hot) but there are tons of grounds. I found it cleaner and easier to create a ground junction block on the ECM mounting bracket in an effort to clean up the engine bay of all the ugly grounds. There is a huge ground cable going from this junction block to the transmission bolt/stud then another going from the mounting bracket to the body. Seems like a good grounding solution. We’ll see! Also labeled everything for ease of service down the road.


Further back shot. I test fitted the glove box to make sure the door swing would clear the ECM. Passed with flying colors!


This is where I ended tonight. I plan on leaving this much exposed until after the initial fire up to make sure everything is wired correctly. The only thing left to wire up is the coolant temp sender and fuel pump. Might be able to crank this beeotch up before Thanksgiving after all!

[ryanroo]

Looks amazing, as always.

[Zoomad75]

Thanks Ryan. Larry is getting into the zone now. Wiring used to be something he dreaded but now after doing 4 trucks with complete powertrain change overs he's really good at it now. Using GM schematics will help troubleshooting if something does go wrong later. He's had no trouble on any of his other builds so I'm pretty confident this will be no different.

I did drop off some more goodies on Saturday after work. One of which was a coolant temp sensor needed for the gauge to work. There was some back and forth discussion on this subject Friday. The stock gauge uses a single wire sender that is just providing a resistance to ground for the gauge to work. The stock 5.3 sensors (which we have 2, one for the gauge and one for the ECM) use a 2 wire hookup. Reviewing the factory schematics for the 5.3 the ground is just returned back to the ECM. Now we could have used this with the right connector and ground the 2nd wire. The question was if the resistance values were the same from the old to the new for gauge accuracy. Next option was surfing the web and finding a conversion sensor on ebay or elsewhere. No time for that option as Larry needs it to be able to fill the cooling system soon. Web surfing found two more options, drill the head to a larger hole for the 3/8 npt pipe fitting needed for the 91 gauge sender or machine down the 91 sensor to the 12m x 1.5 metric hole that the head has.

Talking with my ace tech at work about it, knowing he's got a metalworking lathe we hatched a plan. Now he as well as Larry was skeptical about machining the sensor down, but after what I had found online this had been done many times with good success. I ordered a new sensor from Napa and handed off to my tech to take home Friday night. Later on he sent me a text with the finished product. Seen Here:



Larry threaded it in Sat and found the correct single wire connector to hook it up with. So to all LS swapper's out there, you can use your factory gauges with your swap. We are using a stock 5.3 oil pressure sensor, just like Larry did with the 8.1's in his and with one minor adjustment, the stock coolant temp sensor too. The ECM doesn't need to see an oil psi signal and since each head has a hole for a coolant sensor, the drivers side will get the ecm sensor and the pass side gets the gauge sensor.

Looking at Larry's work on the wiring is just beyond words. As his pics show everything is neat and tidy and using GM logic every step of the way. We are a couple of wire hookups and topping off fluids away from hitting the ignition.

[gloriavoxdei]

Y'all better post a video of the initial start up. I follow all of Larry's builds as he includes an awesome amount of tech detail. Maybe I'll see you guys around since I live up in Florissant, an hour north of you.
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[Zoomad75]

It's a little behind our self imposed timeline, but then again getting right knows no timeline. We were able to get the 5.3 lit off for the first time today. This is where Larry's attention to detail pays off. His wiring and setup of the ECM calibration allowed it to fire up on the first twist of the key. Larry took a video with his Gopro that he'll probably post up later tonight. If I know him, he's back out in the garage right now cleaning up the wiring.

So I took a quick video with my phone when I cranked it up. It's loud without the exhaust, but it settled into a nice idle. Without further delay here's the quick video I took:



We really got a lot accomplished. The alternator wasn't charging so I had done some research on wiring the connector and found an issue. Larry had the bright idea to take the alternator back off and run over to autozone and get it tested since this one was never run and it came from and old co-worker at Workhorse. So I pulled it off and ran it over and it passed the test. I came back and put it back on and studied the schematics a little more. Turns out I got the pins reversed at the alternator. Swapped them around and tried it out and bingo it's charging. Other vitals on the electrical checked out, gauges started coming up and all the lights were working except the dash lighting. While Larry finalized the alternator wiring by looming it up I pulled the cluster out and figured out what I did wrong on the dash lighting. I checked for voltage with the lights on at the pin on the connector for the cluster and had power where I needed it. Turns out my LED bulbs were in backwards. Since LED bulbs are polarity sensitive I popped them out one by one and reversed them and they each came on.

Still got a lot of little stuff to do, but it was sweet hearing the 5.3 rumble to life for the first time in the Blazer. Major kudo's to Larry for busting his tail to get it this far. Watch for Larry to post the better quality video of the first fire.

[MTCK]

Nice work, fellas! Sounds great.

[DirtyLarry]

Albeit a week after our target startup date of Thanksgiving, we finally got her fired up. As Rob said, the ZooK5.3L took her first big breath this afternoon. Pretty uneventful really, but I cheated and already had flashed in a 6.0L Bin file and already had it run for a second or two (literally a rotation or two) before this video was shot. Up until this video, we really didn’t know how well it would start, build oil pressure or anything. We did have some challenges getting the alternator to charge and the dash lights to work but Rob got all that sorted out.

Still got some little stuff to do before it goes to the exhaust shop. Once it comes back from the exhaust shop we can fine tune things after we can hear ourselves think………

Fire in the hole! (Don't know how to imbed videos on this forum). Never understood why posting videos here has to be to G.D. difficult.
https://www.youtube.com/watch?v=9oY7WrHn0vk

Zoomad himself fiddling with something. Never mind the wiring, got a lot of fine routing and clipping yet to do.


Got some wiring clean up to do, fabricate the E-brake brackets and route the cables then haul it to the exhaust shop to quieten the thing down. Once we can hear ourselves thing we can start on the fine tuning.

[Zoomad75]

Long time coming. I'm glad we made some great progress today!

[beamn7]

Sounds good guys! Larry you look freakin hilarious sitting in that thing with no seat! Almost like cheech in Up in Smoke. Nice work guys.
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[Zoomad75]

Since I live in a non-emissions county, no plans on Cats. This system doesn't fire the injectors sequentially, but in a batch fire style similar to the old L98 TPI systems. Based on that, one o2 sensor is enough. The stock style downpipes off the manifolds do have bungs for o2 sensors, but the left side will get a plug.

I wasn't aware ALL LS engines were CARB approved. I know the GM crate Erod engines were, but thought the ruling was the vehicle with the newer swapped in engine had to meet all the requirements of the year of the engine installed. Meaning, cats, evaporative emissions systems and all the other goodies. MEFI for in my form in a 91 probably wouldn't pass CARB's muster. If anybody in CA is looking to do this kind of swap, you need to do the research with CARB to find out what your swap will need to be legal.

[justcuz]

Originally Posted by Zoomad75

Since I live in a non-emissions county, no plans on Cats. This system doesn't fire the injectors sequentially, but in a batch fire style similar to the old L98 TPI systems. Based on that, one o2 sensor is enough. The stock style downpipes off the manifolds do have bungs for o2 sensors, but the left side will get a plug.

I wasn't aware ALL LS engines were CARB approved. I know the GM crate Erod engines were, but thought the ruling was the vehicle with the newer swapped in engine had to meet all the requirements of the year of the engine installed. Meaning, cats, evaporative emissions systems and all the other goodies. MEFI for in my form in a 91 probably wouldn't pass CARB's muster. If anybody in CA is looking to do this kind of swap, you need to do the research with CARB to find out what your swap will need to be legal.

Rob,

Here is the kicker, California actually has 3 different smog rules depending on your location, however engine changes fall under one rule.

There is no real way of telling if the engine is an ERod engine or not, (since it is basically a GM pickup 5.3) so as long as your engine conforms to CARB executive order D-126-31 you should be good. You correctly stated it must include all the emissions equipment for that engine including the EVAP and other required emission control items. This would negate the use of the MEFI controller your using for a post 1975 swap in California.

California has changed, in the fact that if your car did not originally have the availability of the chosen engine you cannot swap it into your vehicle.
So no diesel in GMT400 1/2 ton trucks, no 4.6 or 5.4 in your post 75 ford vehicle.
You can install a fuel injected 360 in your 91 Dodge 1/2 ton, but no Diesel swaps until you step up to a 3/4 ton truck.
The GM LS engine to my knowledge is the only engine certified by CARB that you can legally swap into ANY vehicle post 1975.

[DirtyLarry]

Originally Posted by justcuz

Rob,

Here is the kicker, California actually has 3 different smog rules depending on your location, however engine changes fall under one rule.

There is no real way of telling if the engine is an ERod engine or not, (since it is basically a GM pickup 5.3) so as long as your engine conforms to CARB executive order D-126-31 you should be good. You correctly stated it must include all the emissions equipment for that engine including the EVAP and other required emission control items. This would negate the use of the MEFI controller your using for a post 1975 swap in California.

California has changed, in the fact that if your car did not originally have the availability of the chosen engine you cannot swap it into your vehicle.
So no diesel in GMT400 1/2 ton trucks, no 4.6 or 5.4 in your post 75 ford vehicle.
You can install a fuel injected 360 in your 91 Dodge 1/2 ton, but no Diesel swaps until you step up to a 3/4 ton truck.
The GM LS engine to my knowledge is the only engine certified by CARB that you can legally swap into ANY vehicle post 1975.

Who cares! We live in Colorado

[justcuz]

OK point taken, I guess I'll just stop at the service area and leave my **** there.

[First c10]

Not sure if all LS's are CARB approved but 1975 is the cut off date. so if you install anything in a pre-1976 vehicle there is no smog check required so anything passes...
I had a friend that put a nasty small block in a late 80's(86 I think) 4x4 that was originally a diesel truck.... he never had to worry about getting in smogged since it was classified a diesel truck.....

[Zoomad75]

I can always count on Larry to keep stuff on track! LOL!

[DirtyLarry]

Well, Larry’s portion of the ZooK.5L project is almost done for a while. We still have some loose ends to tie up once it takes a trip to the exhaust shop to quieten it down so we can hear ourselves think enough to finish up the tuning and what not.

Our issues list is getting much smaller…..The alternator stopped charging again, TV cable needs to be hooked up and adjusted, torque converter lock-up wiring finished, and the radiator is leaking at the seam where the tank meets the core. Go figure, as that was one of the parts from the tired old ’75 K5 that we scrapped.

We`ll clean up the wiring near the junction block once the alternator issue is sorted out










We`ll tackle the body work next spring and spray some fresh paint on her


Before

[MTCK]

Just wow. Nice work guys.