csuviper's Junktrk (84 Yota Pickup) Build

Buying my first house with the wife So excited. In contract now. Close Nov. 28.

 

Lol nice, looks like it has been used and abused.
No plans for mine to look like that though. I will hopefully get some good use out of mine.
Need to get the damn engine fixed though.

 

Here's a pic from a last week:

 

I want to get my truck running strong so I can hit the trails before my baby is born.

 

I took my crawler for a ride around the block today. Needs a new battery, has lots of leaks and runs really rough. Have a distributor, cap, rotor and fuel pump on order. Hope to start working on it soon to get it back on the trails.

 

Having the same power issues. Need help. Now I am certain it is the carb. I just changed out the distributor because I wasn't able to achieve proper timing. Now that it is changed, timing is perfect. The truck idles great.
Now when accelerating very slowly the rpm can ramp up and no loss of power. Accelerating quicker or romping the throttle will cause the loss of power. The engine seams like it is choking. You can hear the air rushing past a restriction.

When the throttle starts to open the lower butterfly valve (drivers side) mechanically the engine will roar back to life. That is if it doesn't die at the restricted part.

Questions:
Is the lower butterfly valve supposed to open sooner than when it is contacted by the throttle linkage at the spring?
Is there a problem with the lower butterfly valve?
Is there a problem with the choke?
What is the problem?

 

We shall see about this plastiderp stuff.








lol test triangles

 

Plastidip sucks. Not good for a trail rig. Easy to scratch and you have to peal it all off if it gets messed up. Touch-ups are not possible if you want them to look good.
Not a fan.

 

I was either thinking that or a flat black.
I used the cheap bedliner spray on the roll bar and it looks great. Might go that route.
Need to finish up with getting it running strong before I can get the cosmetics accomplished.

 

I think I've figured out this whole power loss debacle.

I opened up the valve cover to make sure the timing chain was installed correctly and ensure that the crank and cam were synced correctly. The timing looked good. At TDC (top dead center) in compression (set the crank pulley at 0) the cam timing chain sprocket was 1/2 chain link to the left of TDC. Heard that either side of TDC is ok, can't achieve exactly TDC. This brought me back to the thinking it has to be the carb, vacuum or ignition system or worst cast the piston rings.

First is troubleshooting the ignition system. The MSD ignition coil primary and secondary resistance checked out (PR: .08ohms and SR: 3.08ohms) so I have deemed the coil to still be good. I am currently trying to trace all the wiring of the MSD system to make sure it's hooked up correctly with no shorts. I am very concerned with the wiring job so I will eventually rewire it all. I want to troubleshoot before I clean up the electrical however. The MSD control module looks ok but not sure if it is functioning properly. Need to read up on how to test to see that it's keeping up and functioning properly.

The next thought was spark plugs. Pulled them and found them black. Definitely a problem. That makes me take a step back. I replaced the distributor, rotor, cap and wires a week back. When I did that I was actually able to get the engine ‘in time’ with the timing gun and fine tuning of distributor placement. The truck would idle great. I checked out the old distributor and noticed that it was dirty inside and the advance was not functioning. This would explain loss of power last summer because the distributor wasn't adjusting to the speed causing no spark. This along with the recent testing caused the plugs to get all gummed up. I also know that I had the fuel mixture set way wrong. I was flooding the engine. The screw was nearly turned all the way out.

I haven't checked compression so I plan to do that as soon as I can. I will either rent or purchase a tester. I am really really hoping that it checks out. I don't want to have to replace rings.
I traced and retraced the vacuum lines last spring/summer so this shouldn't be the problem. The diagram was unclear in some areas so I could have a couple lines mixed up. I am not ruling this out as of yet but putting it back on the priority list.

The carb was rebuilt by a friend that has rebuilt his old 81 crawler carb several times. I trust that he did a good job. What I don't trust is the carb itself considering the condition of the rest of the truck. I will make sure the ignition and compression are good before troubleshooting more here. I will however turn the fuel mixture back to stock configuration. I read that is 4 1/2 turns out from closed position. I will probably start around 3 to burn off the excess and make sure I don't run rich again. If the other items are in check and the carb is next on the list, I might just replace it with a rebuilt or aftermarket carb. Again hoping that the problem is fixed within the ignition section or vacuum, the cost of a cab is outrageous.


If you like to scroll to the end without reading, you are in luck. The skinny is that I believe the distributor is the main cause of the problem that trickled down causing more problems. Still need to continue troubleshooting to see if the problem is fixed after new plugs and turning the fuel mixture down.

... or I could be totally wrong and its back to the drawing board.

 

Here is a pic of the cam sprocket with the valve cover off. The dimple is slightly to the left (1/2 link from TDC).



Here are some pics of the old distributor. You can see the wear.



Pic of the new distributor


Pic of the diry plugs

 

In the end I think the timing is right but not positive its right. Pretty sure but have doubt. You know what I mean. With it in its current state after rebuild last year I was able to get the correct timing reading from the timing gun and I was able to pass emissions with it before the problems that it faced when reaching ~50 mph or additional load from a hill.

Here is the list:
1) Bought the truck, noticed leaks, decided to replace head gasket, all other gaskets to get there and other important components like oil pump, water pump, crank and cam sprockets, chain guides/tensioners, etc.
2) Dissasembly (last year), put it at TDC before disasembly
3) Reassembly of timing chain started with finding the TDC of the crank with head removed. Watched the piston peak before dropping. (That lined up with the pulley mark at 0 on the oil pump timing mark).
4) Installed new timing chain guides and new tensioners.
5) Installed new crank sprocket (contrary to the order that I mentioned before)
6) Installed head.
7) Installed new cam sprocket to find TDC.
8) Rotated cam to 12 o-clock. I remember putting it on with wrong placement first because the valve contacted the cylinder. (don’t worry it only hit as I was slowly rotating the cam by hand to get to 12o-clock.)
9) Removed cam sprocket and reinstalled with the timing chain onto the cam shaft, possibly not lining up the shiny chain links, don’t remember.
10) Installed the timing chain cover.
11) Installed new oil pump
12) Installed new water pump
13) Installed the oil pan.
14) Installed everything else….

Here is a pic just after the timing chain cover was installed.


After the semi rebuild from last year I experienced the following problems
1) Could not quite get the correct timing reading. The closest I could get was 4 before TDC. Truck idled fine and could be driven at slower speeds and even crawl without problems.
2) At ~50mph or hitting the accelerator on a hill the truck would lose all power or jerk violently. Once I lost power I could not regain anything until slowing down to about 25mph. If it jerked violently I could push the clutch in wait a sec and then accelerate again. Sometimes it would be ok after that sometimes it would lose power or jerk violently again.
3) After replacing the distributor the truck the truck idled great and I was able to achieve a good range in the timing. Seemed run smoothest around 5-8 before TDC. When accelerating the truck would lose all power and cut out. Stationary pulling the throttle cable the carb sounded like I was starving for air like the butterfly’s were almost close and it was sucking for air. The truck would choke out and die. If you quickly hit the accelerator it would choke out a little but scream once the lower butterfly opened up.
Because of the problems experienced above I am troubleshooting all possibilities so that I can actually drive on the highway to get to the trails. Last year when heading up I had to pull over every 100’ on the highway to let the truck settle after the power loss and get going again. Most of the drive was on the shoulder letting people pass. I am not doing that again this year. Need to figure out the problem.

My next step is checking compression. Already on the to do list. Didn't change rings when i did the semi rebuild so i am a little worried.

 

OK, so i have some news.....
Good news and bad news.

The good news I have a new tool:




Well a little more good news:
I am in the low range of range of cylinder leakage. As some say acceptable range.

The bad news: :cry2:
I will have to change the rings at some point, probably sooner than later.

I am fairly confident that the air was leaking past the rings and only there. I say this because the air was coming out of the timing chain area. Is this correct???????

Here are pics of each cylinder leakage gauge:

Cylinder 1


Cylinder 2


Cylinder 3


Cylinder 4



Not very happy about the amount of leakage. They are however fairly consistent across the board. That to me says its normal weardown and not a big failure of a ring or two.



What this means is that I will have to see if my compression is acceptable. If the compression is at an acceptable then I will close her up and see If I can get her running well. If compression is bad then i either pull the engine apart and change the rings or replace the engine or replace the truck.

Compression test was slightly low but acceptable. Had a shitty tester that leaked so it could have been off. Darn rental equipment.

Ok so I got it running again, timed again and took it to the streets a couple weekends ago. When in the garage just throttling it, everything was good. Idled and revved up just fine. Hit 60mph and the same thing happens again, loss of all power.

 

So I purchase a 1yr old Weber carb yesterday and stock ignition coil that I know works. I am excited to put it on.
One thing I'm worried about is that it didn't have an adapter plate. I thought you had to have adapters in order for it to work. I am now worried that the intake manifold wasn't stock and that it was actually aftermarket specific for the carb. The guy I bought it from (friend of a friend of a friend) bought the truck from the PO with the carb on it (brand new at the time). Good news is that if it doesn't fit he will sell the intake manifold to me for $20. Just means another trip to get it and another week without the truck to its full potential.

Hitting up Left hand this weekend. If I can get the truck running well I will drive it there. If not I will tow it. Runs good at slow speeds so why not test it out.

 

Weber install questions for those that have installed one

1) I am having troubles finding how to hook up all the vacuum lines for my 84. Does anyone have pics or a good diagram from an 84? Lots more going on than what the diagram shows from Weber. The EGR vacuum modulator has 3 connections, not one. Is the dist connected to the vacuum switch still or just the carb? Where does the ASV vacuum line go to, or does it get plugged?

2) Will the Weber pass emissions? I say this because it seems like alot of vacuum lines are blocked off and/or re-routed.