1972 chevy super Cheyenne help
 

I have a 1972 chevy super Cheyenne 402 big block, C10 400 turbo hydromatic transmission. I rebuild the heads and I tried to set ignition timing but was little difficult, I can't set the right time. Also, I bought a new carburetor for this chevy 72. I need help with the vacuum lines diagram and idle mixture for this new carb. the old carburetor is different in vacuum lines and I discovered that was made for chevy 73 and all vacuums lines are different from the new one.( I don't know if the last owner replaced this carburetor or is original.) I going to see if I can set the ignition timing and drive around the corner. Thanks.

Re: 1972 chevy super Cheyenne help
 

Sorry I tried to attach some pictures but I failed.
I will be trying to attach some pictures today.

Re: 1972 chevy super Cheyenne help
 

Do you have the vacuum lines hooked up? Is the power brake port at the back plugged or hooked to the booster? I've seen guys bolt on the Edelbrock and not look at the back where the brakes go and leaves a HUGE leak and makes it run all kinds of stupid.
I'd go back and trace through the timing steps to make sure that is close to right then check the firing order[18436572] again It is easy to trip up right there. Once basic static timing is done you should be real close , but check the carb first is you have the spreadbore intake you may need the gasket/adapter to plug the vacuum leak there and the others places need to be checked too. jim

Re: 1972 chevy super Cheyenne help
 

Thanks, Jim.

Re: 1972 chevy super Cheyenne help
 

Help please, my friend did the ignition timing and I am not sure if he did it right. when I set in drive the truck feels ok, but when I put in reverse shakes a lot. Happened when I tried to park in my garage. I just drove one time around the corner. Also , today I replaced all the hoses and I tried to drive but I hear a weird noise inside the engine, like nock noise.

Re: 1972 chevy super Cheyenne help
 

Maybe it's mad at you for calling it a super Cheyenne when it's correct name is a Cheyenne Super. Sorry, just had to say it. Also sorry I'm not sure what to tell you by your description. Is the idle high enough when in gear? What is shuddering? The engine, whole truck, just the transmission? How long have you had it? What was the reason for the head work? What were the symptoms before that was done? If it was an ignition timing problem all you'd need to do is rotate the distributor till it runs better. Does it have points or HEI? Are the unused vacuum ports blocked off? Is one run from the distributor to the base of the carb?

Re: 1972 chevy super Cheyenne help
 

Id number of my New carburetor.

Re: 1972 chevy super Cheyenne help
 

here is a little advice from experience. have you set the valves properly? you said you rebuilt the heads if it isn't running right you may have the valves adjusted too tight. the book says 2 turns on hydro lifters but I only do half turn. these aren't race cars.

Re: 1972 chevy super Cheyenne help
 

I have this truck for 10 years, but 2 years ago the engine broke and I sent to machine shop to rebuild. After that, I had a lot to problems, the motor had 5000 mile and started to leak oil on heads . When I removed the heads a lot to oil in piston and a sent to machine shop the heads to rebuild once again. Now the engine is complete and my friend that is mechanic came to check the valve timing and he did the ignition timing. But I am having trouble. I drove half mile around the corner and it was ok but when I put in reverse to park in the garage the engine started to shake a lot. I have new carburetor, new vacuum hoses and fittings for brake boster. Today I tried to drive but when I fired up I hear a noise and no runs smooth like the first time.

Re: 1972 chevy super Cheyenne help
 

New carburetor.

Re: 1972 chevy super Cheyenne help
 

Lol, you right special-k.

Re: 1972 chevy super Cheyenne help
 

well a noise could be almost anything. since you had the heads off I would say its valve noise or its pinging from having the timing to advanced. if its shaking and you think there is something wrong do a compression check.

Re: 1972 chevy super Cheyenne help
 

Well, I did 3/4 turn as the manual repair say, but when my friend came to do the ignition timing he remove the valve cover en checked the valve and he told me that the valves needs little more, and he did maybe 1/4 turn. I am not sure . I am going to see this weekend.

Re: 1972 chevy super Cheyenne help
 

:burnout::bowtie: anyone knows a shop here in Dallas, TX to send my truck to diagnose and fix all issues. I am tired I can't wait more, I want to drive it .:nx::bowtie:.

Re: 1972 chevy super Cheyenne help
 

Have you pulled your plugs to inspect? Could have fouled some in that little trip if something wasn't quite right yet. Not sure why your rebuild dumped oil into the cylinders in so few miles. I wonder what they did different the second time. Have the heads been magnafluxed? Sounds from here like it's doing the same thing it was before and after the rebuild. Check and see if any plugs are oil contaminated.