1974 K10 Dirty Sancho

[mrk5]

On the ignition feed issue, I thought there were some feeds that are intentionally dropped from the circuit when the key is in start to minimize the draw on the battery.

Did you do the full initial setup of the PF4?

 

[skunked]

On the ignition feed issue, I thought there were some feeds that are intentionally dropped from the circuit when the key is in start to minimize the draw on the battery.

Did you do the full initial setup of the PF4?

Might be but I was able to start and run the truck at least a dozen times with the way it was wired. Then all of a sudden it would drop off while cranking. The confusing part about it was the edelbrock EFI was showing voltage and it wouldn’t lose it’s connection (Bluetooth) to the ECU when the voltage dropped. It’s clear the voltage figure displayed is from the battery 12v feed, not the ignition source.

I’ve gone through the wizard setup twice.

 

[skunked]

For whatever reason the coupler on the steering shaft (gear box side) wasn’t clamping down on the steering gear input shaft properly. I’m pretty sure I’m trying to use the steering shaft from the C10 however it must be the larger spline design. I found a dorman steering coupler assembly with the 3/4” spline design and I’m back in business. Now I need a rear driveshaft, hopefully ORD ships the output flange soon so I can measure and order a 1350 CV driveline.

 

[mrk5]

Might be but I was able to start and run the truck at least a dozen times with the way it was wired. Then all of a sudden it would drop off while cranking. The confusing part about it was the edelbrock EFI was showing voltage and it wouldn’t lose it’s connection (Bluetooth) to the ECU when the voltage dropped. It’s clear the voltage figure displayed is from the battery 12v feed, not the ignition source.

I’ve gone through the wizard setup twice.

That's true, I can verify that after going thru my debacle with the wire on the exhaust manifold.

I don't remember if I saw it in the thread, what are you using for booster and master cylinder. I'm looking to replace mine in the 73 in the near future.

 

[skunked]

That's true, I can verify that after going thru my debacle with the wire on the exhaust manifold.

I don't remember if I saw it in the thread, what are you using for booster and master cylinder. I'm looking to replace mine in the 73 in the near future.

The booster was a reman that was already on the truck, I just scuffed it and painted it. For the master cylinder I went with a later model plastic tank/lid from Ac Delco (PN#19176456) . I want to say it was a mid 80’s application, same one I run on the other truck.
https://www.summitracing.com/parts/ADO-18M217

 

[mrk5]

The booster was a reman that was already on the truck, I just scuffed it and painted it. For the master cylinder I went with a later model plastic tank/lid from Ac Delco (PN#19176456) . I want to say it was a mid 80’s application, same one I run on the other truck.
https://www.summitracing.com/parts/ADO-18M217

Did you have to change the brake lines to work on that master cylinder? I was trying to decide if the lines in your picture were new or not.

I figured out the booster in my C10 is a reman unit already. It had a paper tag around the check valve stating it was reman'd and changing the check valve voided the warranty. I found in doing the parts searching for boosters that they don't replace the diaphragm in the reman units unless it's damaged. I was disappointed about that; seems like that would be something that needs replaced due to age. But I guess they work okay.

 

[skunked]

Did you have to change the brake lines to work on that master cylinder? I was trying to decide if the lines in your picture were new or not.

I figured out the booster in my C10 is a reman unit already. It had a paper tag around the check valve stating it was reman'd and changing the check valve voided the warranty. I found in doing the parts searching for boosters that they don't replace the diaphragm in the reman units unless it's damaged. I was disappointed about that; seems like that would be something that needs replaced due to age. But I guess they work okay.

The brake lines are new replacement lines for a 75 K10 from inline tube and they bolted up fine.

Don’t get me started on the reman boosters, I went through 3 of them on the other K10. My suggestion is to leave it alone if it’s not broken.

 

[mrk5]

The brake lines are new replacement lines for a 75 K10 from inline tube and they bolted up fine.

Don’t get me started on the reman boosters, I went through 3 of them on the other K10. My suggestion is to leave it alone if it’s not broken.

My pedal is soft so I'm thinking either master or booster. I'm also probably too used to the hydroboost brakes, but even the non-power drum brakes in the 66 feel firmer.

I found 1 new booster on Summit but it's pricey compared to the reman.

 

[skunked]

The vacuum brakes are pretty soft. The non power 66 brakes should feel a lot firmer in comparison. Unless the pedal is leaking to the floor I don’t think it’s unusual. However a brake fluid flush wouldn’t be a bad idea if the fluid age in unknown.

 

[Truckman4life]

Soft pedal is master. Harder than normal pedal would be booster issue as in lack of assist.

 

[skunked]

I pulled brake fluid through the lines with my mighty vac, installed a 11/32" vacuum line for the booster and pulled the truck out onto the street under it's own power. With the lockouts engaged, 4LO and my ass sitting on the cab floor which is somehow pretty comfortable. The EFI for some reason doesn't want to stay running for more than 10-15 seconds until it goes closed loop and then it runs fine. Tires rubbed the front fender coming out of the driveway so I'll be adding a EZ-Inch and/or a 1" pucks depending on how the springs break in. I'm still waiting on the output flange from ORD so I can order a rear driveshaft, hopefully it shows up tomorrow so I can place an order Monday. Lots of little parts on the way including lug nuts, radiator bracket, bumper bolts, door seals, e-brake cable etc.

 

[skunked]

I was having a bitch of a time trying to find firewall boot(s) for the clutch linkage to replace the used torn boots I have. Every major retail truck parts supplier I researched didn't list the part and GM supposedly stop making them long ago. 4speedconversions.com sells a different version however they're sold out currently. I finally ran across another boot (Nova/Camaro application) that looked very similar and found a amazon review saying it worked on a squarebody so I figured this could be useful information for the third pedal lovers. OER PN# 3973089 and I ordered one to test fitment.

 

[GWeakland620]

I pulled brake fluid through the lines with my mighty vac, installed a 11/32" vacuum line for the booster and pulled the truck out onto the street under it's own power. With the lockouts engaged, 4LO and my ass sitting on the cab floor which is somehow pretty comfortable. The EFI for some reason doesn't want to stay running for more than 10-15 seconds until it goes closed loop and then it runs fine. Tires rubbed the front fender coming out of the driveway so I'll be adding a EZ-Inch and/or a 1" pucks depending on how the springs break in. I'm still waiting on the output flange from ORD so I can order a rear driveshaft, hopefully it shows up tomorrow so I can place an order Monday. Lots of little parts on the way including lug nuts, radiator bracket, bumper bolts, door seals, e-brake cable etc.

Looks real good sitting outside the driveway!

 

[skunked]

Looks real good sitting outside the driveway!

Thanks and I thought so too. I had to pull the other truck out so it was a good opportunity for a photo & size comparison.

 

[Bent77]

What water temp are you hitting closed loop?

 

[skunked]

What water temp are you hitting closed loop?

I just fired it off to find that out and it’s running fine. Coolant temp was 59 before I started, dropped to 57 after running for 10-15 seconds and then it went closed loop.

 

[82355]

It honestly isn’t that bad driving them without a seat.

I was surprised.

Martin

 

[mrk5]

If you watch the AFR you'll see it's reading 10.0 until it goes closed loop then starts reading real numbers. That's the warm up time for the O2 sensor. Mine is like you describe on the first start for the day with cold iron engine. As soon as the O2 sensor warms up, the idle smooths out because it's in closed loop.

I haven't driven the crew cab since finishing the PF4 install, but I'm curious if it does the same O2 warm up. I've never noticed it before. The closed loop on the Sniper is different too. It doesn't do closed loop until coolant hits 165° but the PF4 does as soon as the O2 sensor warms up. Then it starts the "O2 Learn" at 165°. The Sniper doesn't have an O2 Learn.

 

[skunked]

If you watch the AFR you'll see it's reading 10.0 until it goes closed loop then starts reading real numbers. That's the warm up time for the O2 sensor. Mine is like you describe on the first start for the day with cold iron engine. As soon as the O2 sensor warms up, the idle smooths out because it's in closed loop.

I haven't driven the crew cab since finishing the PF4 install, but I'm curious if it does the same O2 warm up. I've never noticed it before. The closed loop on the Sniper is different too. It doesn't do closed loop until coolant hits 165° but the PF4 does as soon as the O2 sensor warms up. Then it starts the "O2 Learn" at 165°. The Sniper doesn't have an O2 Learn.

It’s dying while it’s in open loop. The AFR is bouncing around during the process. It’s acting like it’s running out of fuel or the ignition is being turned off because it’s an abrupt shutoff. After 15-20 restarts and it dying it will run and stay running once it gets to the closed loop.

In other news, the output flange finally showed up from ORD, it’s been painted and installed. The driveline was ordered with a 1350 CV and a 1350/1310 conversion u-joint at the other end. Should be ready tomorrow.

Reverse lights are wired, just had to find the green/light green plug on the bottom of the column and extend those wires to the reverse light switch.

Ran the tail light harness to the back of the truck and in the process I realized the bracket that pushes the brake light switch was missing from the manual pedals. I found the bracket from the automatic C10 pedals and it was different. Rather than trying to source the correct bracket I decided to cut it down and weld it.

 

[skunked]

Here’s a picture of the ECU mounted on the gas pedal bracket.