Atl-atl's K5 Blazer Four Wheel Camper "The Crawlin Cabin" documentation thread!

[Atl-atl]

You can remove the vacuum switch and put a pipe plug.
Wait how are you passing Phoenix Nazi smog test?

Cool. Do you think this alone could be causing the CPL to not get enough vacuum/causing my running rich issues?

Im not sure ha. I bought it in Tucson and registered it in Phoenix back in April. They let me register it without a smog check. Ill hopefully be LS swapping it soon in which case it should pass smog. If worse comes to worse I can register it at my cabin in Colorado where I wont have to do emissions testing on it.

 

[Wes Harden]

No that is a separate vacuum circuit.
It probably will only be an aesthetic up grade.

 

[Wes Harden]

In Kommiefornia that wouldn't have passed a visual.
Not is easy to put an ls in and pass smog. It can be done just slot bureaucracy.
Mine is registered in Mohave county, no test there. I love it $129 for 5 year tag. Less than 1 year in CA.

 

[Atl-atl]

Ok update time. My dumbass decided to work on it at the hottest part of the day because I cant help myself. I capped the thermostat lines and replaced the line from the CPL to the vacuum advance on the distributor. The connection at the vac advance and the CPL were very loose, the hose wasnt completely rotten but it was new and not tight at all. I also discovered another leak, at the vacuum ball. A line I had previously replaced came off the bottom of the ball again so there was a massive vacuum leak. My guess is this definitely affected the operation of the carb because there was no reserve of vacuum. Makes sense why it would act up after long cruises at speed because it would run out of vacuum.

Could this have caused the carb to switch into a different running mode and flood the engine?

Also here are two videos of the carb function. Cold start, truck has been parked in this spot for 3 days. I did mess with the throttle linkage before taking the video though so I probably primed the carb before starting it. I did not touch the throttle pedal at all on startup.

I thought it had 5 settings but it seems to only be 4.

 

[Wes Harden]

well that is the choke circuit, and other than maybe a little fine tuning thats the way it needs to work. how warm was motor in those vids?

 

[Atl-atl]

well that is the choke circuit, and other than maybe a little fine tuning thats the way it needs to work. how warm was motor in those vids?

Well "cold" start but its about 110 degrees here today so the motor was 100 degrees or more. That was the first start in 3 days.

 

[Wes Harden]

need to see what it does after motor is fully warm @ 160* plus

 

[Wes Harden]

it does appear that the vacuum can is creeping. could be can or hose. there is a rod that goes to the intake manifold and connects to a spring that controls the tension on choke, there is a small possibility that the spring is overpowering the vacuum can.
When you where traveling though the engine was fully warm, the idle rpm was climbing like in second vid?

 

[Atl-atl]

need to see what it does after motor is fully warm @ 160* plus

Ok, warm start? Or just idling while warm?

it does appear that the vacuum can is creeping. could be can or hose. there is a rod that goes to the intake manifold and connects to a spring that controls the tension on choke, there is a small possibility that the spring is overpowering the vacuum can.
When you where traveling though the engine was fully warm, the idle rpm was climbing like in second vid?

When fully warm the idle does not creep, its very low, like almost stumbling low. I think it was creeping back up because I cut the choke cycle short for the video. Would that make sense? Ill try to drive around a little to warm it up, its too hot for no AC right now though haha.

 

[Wes Harden]

yes that make sense. so when the truck had issues on your trip, did you push the choke weight down to make it run better? what was the symptom? no power, hesitation, surge, miss ?

 

[Atl-atl]

yes that make sense. so when the truck had issues on your trip, did you push the choke weight down to make it run better? what was the symptom? no power, hesitation, surge, miss ?

I did push the choke weight down but that didn't seem to make it run any better. If I push it all the way down and hold it, the engine will die. If you push it up, idle speed increases. Also, these videos are all with the truck in park. When its in D or N the idle is even slightly lower and more bumbling but it doesn't seem to miss and it never dies. Coming off idle, coming off part throttle, moving through the gears etc. it always holds an idle. Except in the highway driving condition. Thats where it will cruise for a while and then it will start to lose power when you try to give it throttle. Going downhill with just the tiniest bit of throttle, 5% or less, it will keep going forever. On flats or uphill the more throttle you give it and the longer the time cruising, it will start to lose power more quickly. Until it eventually will not accept any throttle. If you force it full of gas pedal to the floor, let off and then give it part throttle it will backfire with flames out the tailpipe. If you put the pedal to the floor and hold it, it will eventually die.

Here is a hot start and idle.

 

[Wes Harden]

The idle speed can be adjusted on the driver's side. Turn up it up 1/2 turn at a time. prob to a max 2 turns. to far and the truck will run on at shut off.

So your problem sounds a lot like what I am dealing with on my suburban same carb, won't cruise under a little load. I have tried 3 mechanical pumps and none of them will allow the truck to cruise in high gear under light load. I put an electric pump in, and ran great. The electric was a low pressure external pump and it failed in 1 year.
So current plan is to upgrade the electric pump, add a fuel pressure regulator that has a return port, for excess fuel back to tank. I think extended idle with pump pushing against a dead head over heated my original electric. I also have new main jets coming to up size the fuel ratio.
These trucks weren't designed for alcohol content in our fuel. That LS swap will solve the alcohol issue, you will be converting to EFI tank and pump for that.

 

[Atl-atl]

The idle speed can be adjusted on the driver's side. Turn up it up 1/2 turn at a time. prob to a max 2 turns. to far and the truck will run on at shut off.

So your problem sounds a lot like what I am dealing with on my suburban same carb, won't cruise under a little load. I have tried 3 mechanical pumps and none of them will allow the truck to cruise in high gear under light load. I put an electric pump in, and ran great. The electric was a low pressure external pump and it failed in 1 year.
So current plan is to upgrade the electric pump, add a fuel pressure regulator that has a return port, for excess fuel back to tank. I think extended idle with pump pushing against a dead head over heated my original electric. I also have new main jets coming to up size the fuel ratio.
These trucks weren't designed for alcohol content in our fuel. That LS swap will solve the alcohol issue, you will be converting to EFI tank and pump for that.

Thanks for all your help! Ill continue to tinker with it a little and report back. I have a feeling its a fuel pump issue also. Thats kind of what people have been saying all along. I might try one of those cheap in line electric pumps just to see if it works and keep spare parts in the truck at all times. Im actively working on sourcing an LS swap so its only a matter of time. Do I need to swap the tank for EFI? Ive heard people using a TPI Camaro in-tank pump and Corvette regulator for their LS swap with success.

 

[Atl-atl]

Going out on a bit of a limb here but bare with me. Now that I think through my problem, when I drove up to Flagstaff I only had one unplanned stop where it died. It was at a ~7000 foot pass after cruising for an hour. This seemed similar to the vaporlock issues I thought I had been having. Once it cooled off and started back up, it made it the rest of the way to the camp site with no issues. We did some mild offroading/washboard dirt roads on the way in and out of the campsite. Its possible the vacuum leak at the reservoir developed thanks to the bumpy road, causing it to behave much worse on the way home from Flagstaff. So my problems might be a mix of vaporlock and vacuum leak.

 

[Wes Harden]

Possible. Vacuum leaks effect the air fuel ratio, outside of the carb.

 

[Moody Bricker]

What u need is starting fluid
Tachometer
Vac gage. ...
Start ,set ide to 850,
Spay the stating fluid over each vac line if increase bad hose
Spay under carb to ck gassgets
Spray intake gassgets
Then set idea mix screws to max vac. Reading, reset idle back to 850. Test drive..............jm2cw
Spay intake gassgets

 

[Wes Harden]

Brake/carb clean will work too. Less chance of a fire, or getting stoned.

 

[ZooMad75]

Thanks for all your help! Ill continue to tinker with it a little and report back. I have a feeling its a fuel pump issue also. Thats kind of what people have been saying all along. I might try one of those cheap in line electric pumps just to see if it works and keep spare parts in the truck at all times. Im actively working on sourcing an LS swap so its only a matter of time. Do I need to swap the tank for EFI? Ive heard people using a TPI Camaro in-tank pump and Corvette regulator for their LS swap with success.

Yes, you will need to swap the tank. 87-91 K5 TBI tank will swap right in and have the correct baffle for the in-tank pump. You'll need a sending unit for the similar year range tank that will have the provisions to mount the in-tank fuel pump to it. I'm using an AC Delco pump for a TPI Camaro since my ECM requires a little less fuel pressure than the standard Vortec LS requires. Uses the stock TBI fuel lines up to a point with the fuel filter.

 

[Atl-atl]

Yes, you will need to swap the tank. 87-91 K5 TBI tank will swap right in and have the correct baffle for the in-tank pump. You'll need a sending unit for the similar year range tank that will have the provisions to mount the in-tank fuel pump to it. I'm using an AC Delco pump for a TPI Camaro since my ECM requires a little less fuel pressure than the standard Vortec LS requires. Uses the stock TBI fuel lines up to a point with the fuel filter.

I need to do some more research before I make any additional purchases related to the LS swap. Looks like I can spend $500 on a Holley in-tank pump for my non fuel injected stock tank or buy a new TBI tank for $100 and whatever pump Id need (Walbro 255 or whatever) for the motor I wind up with. Ill have to pick your brain over the next few weeks to make sure I get everything right.

 

[Atl-atl]

Well I havent let the stupid carb issues get in the way of working on other things so I tore into the doors this week. Im trying to get as much done as possible before Im out of my house and dont have anywhere to work on the truck for a while.

40 years worth of dust is residing inside of every panel of this truck.

All of the window seals/wipes/trim were completely dry rotted to the point the rubber wasnt rubber any longer, it was plastic. Literally had to chip a bunch of it out with a hammer and chisel/screwdriver. Wound up with a bunch inside the door before I realized I should put something over the window opening so sh*t wouldnt fall in.

New stuff looks good.

I wound up missing one rubber piece to reset the triangle window glass so I didnt get that done. Hopefully it doesnt come back to bite me since I got it all back together already ha.

I completely cleaned and regreased the tracks and pivots on the regulators and white lithium-ed all the hinges, handles, lock cores, springs and misc. moving parts. Everything works incredibly well!

[video=youtube_share;svcuCKDSbfk]

Reused my crappy door pockets for now because the ones I wanted were out of stock at the time. Same goes for the armrests. Not sure if I want to try finding the matching "buckskin" ones, get black ones or use slightly different saddle colored ones like I have. Everything is brand new except the switches and switch trim.

The drivers door for some reason had an extra 18" of wire twist-tied into the window motor. Not sure why, the factory wiring was long enough to reach so I took out the patched in piece and cleaned up/re-taped all the wiring in both doors and reassembled everything.


Driver side

Passenger side