Camshaft ??
#1
Camshaft ??
Anyone have any advice on camshaft replacement. 83 K5. When I put the new engine in I didn't break in the cam. (2500 miles ago)It runs okay unless I am pulling my trailer. It is gutless under load. Does this sound like the cam? I have adjusted the carb, set the timing and at idle the vacuum gage reads a steady 18. I drove it around and it ran alright until I hooked up my trailer(2500lbs) it barely made it up hills. I had the gas pedal to the floor and it wouldnt keep up with traffic. Then unhook the trailer and it drove okay, it still lacked power going up hills but I kept up with traffic.
#2
I would suspect more of a carb issue than cam. What for a carb do you have on it? Have you rebuilt it completely?
#3
It is the original carb, freshly rebuilt. I took it apart and checked the float, and the areas that normaly leak, filled up the bowl and let it sit for a while. The only thing I found was the adjustment was way out. The primarys were so rich that when I turned the idle adjustment screws there was no effect. I leaned out the primarys, after making the small tool to gain access to the weird screw at the top of the carb. I adjusted the carb using vacuum readings and it was running great. I drove it all over and throttle response has never been better. Then... I hooked up the trailer and as I crested a large steep hill there was a super slow truck in front of me and I couldn't get any speed after that. I unhooked the trailer and it runs okay exept for up a big hill, it is very subtle but I can feel the lack of power.
#4
How's your timing advance?
#5
The timing is set at 8 btdc. I followed the procedure of setting the timing using the sticker under the hood. It has new wires, plugs, the distrubutor was new when I put the engine in. I am pulling my hair out on this thing. I have been out of work for 8 months and I have a job starting next week. I got to get this thing dependable. I appreciate your help.
#6
Are you sure the timing is coming in correctly under load?
If the cam is the direction you want to go, you could either verify the lift/duration & timing or just swap it out with something better.
If the cam is the direction you want to go, you could either verify the lift/duration & timing or just swap it out with something better.
#7
How to check the timing when it is under load? Yesterday I measured the lift at the pushrods and there was no evidence of any flattening. I also checked for slop in the timing chain and there was none.I am happy about that. Today I am going to start all over. Since the problem is seeming to be either ignition or carb I a going to buy a 40.00 computer code reader. Both the carb and the dist are attached to the computer maybe this will tell me something.
#8
It really isn't something you can check too readily without having it on a dyno. I would pull the distributor and make sure that the vacuum advance dashpot and timing weights/bushings/springs are working properly.
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