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I am still working on my truck trying to get it running so I can start driving it but I have had constant bad luck. The truck is a 78 chevy 1/2 ton it has stock but fresh 327. I installed a edlebrock carb model #1400 600 cfm emissions carb brand new from the parts store. So other than the new carb the exhuast is the only thing that isnt OEM. The problem is the truck runs fine when its sitting in park but when under a load and I mean just under its own weight it it gets like it doesnt have any power and it pops the neigbors probably thing I am doing a driveby. Ok I lied about everything being stock the fuel pump is an electric holley pump I have the pressure regulated to 5.5 psi. So I was talking to my father inlaw the mechanic and he gave me an old ignition module to try so I tried that and it ran worse. So thinking I had the problem figured out I picked up a new ignition mod from the parts store. along with new: coil,cap,rotor. STILL the thing runs like crap. I was mad last weekend or at least really frusterated with the situation so I decided to take it down the street and really flog it hard thinking maybe it just needs to be cleared out it didnt clear out it felt like I was trying to tow a concrete truck once again no power. Im beginning to beleive that there is something fooey with the timing I set the initial timing to 8* like it says to do on the little sticker that the emissions tester guys use for refrence. I pulled the vac line off and plugged it when I set the timing and when I rechecked it last night everything checks out. I have heard a few people talking this week about how they dont use a timing light they advance the timing to where it allmost wont start then back it off a little and call it good. I dont know about that method but I do know I am out of ideas.

Sounds like the timing is way off. Either off a tooth on the dizzy or the timing chain. Had the motor been run before you put it in the truck? If it ran fine before, that would eliminate the chain.

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FIAA!

SFPP!

Try this:

Start the truck and get it to operating temp. Loosen the dist. and bring the RPM's up to 2000 or so. Advance the timing until the truck starts to run bad, then retard it just a bit until in clears up. Then test drive it and see how it goes.

Are the valves in adjustment? Just a thought.

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Yesterday I played around with it and this is what I came up with. I was a little leary of just cranking the distributor around so I got out my timing light and advanced it to 32* initial timing. I went for a ride and it ran 75 times better than it was. I still get a slight popping at certain cruise speeds and when I hammer the peddle down from any speed it kinda hesitates and coughs once or twice and then it takes off some what ok. Next thing I did and I really hate to say this but I started reading the owners manual for the carb. All I can say is I remembered why I dont read owners manuals Its all a bunch of stuff put into terms that I dont really understand. The one thing I did spot in the book is that it says possible lean condition and gives some of my problems as an example. but now there is like 3 things I saw that I could change. 1. metering rods 2. jets and 3 the accelerator pump has 3 holes to hook the linkage too. Now 3 things for a person like me that doesnt know much about carbs could be dangerous I mean where do I start. I have another edlebrock performer carb I was thinking about trying the metering rods out of that to see if it improves or gets worse. To make a longer story short as possible I got the truck from my father in law the mechanic or auto tech as he likes to call himself he pulled his motor out of the truck and installed the motor I have now. It ended up having a dead hole so he tore it down and re ringed it I told him I was interested in it if the price was right he made me a deal that involved me putting the motor together from the point he had left it basically he had the pistons back in the block along with the cam. I finished the assembly from there. I will see him hopefully today and I an going to ask him if he did anything weird with the cam when he re instlled it. I did notice that the marks on the cam chain sprockets appeared to be lined up like I would have set up. Factory specs say 8* of initiall timing shouldnt it at least be in the ballpark set like like that. The thing that kills me is living in california I have to pass the emissions crap so cranking the timing way up wil make it fail the test. I just got my regisstration renew paper work in the mail good thing it doesnt have to pass the smog machine this year.

Your a tooth off on the distributor , if you can go ahead and put say 40 * initial in it see what it does . You can also move the pump arm to the hole closest to the pivot . This will hel you lean transition to the primary jets . I would start with timing first .

I changed out the metering rods and moved to the closest hole on the acc pump it ran little better yet. I didnt think it would matter if it was off a tooth as long as the number one spot on the cap lined up with the rotor and then the timing light reading off the #1 plug wire. LOL stupid mistakes are easy to make when you dont have a whole lot of experiance. Is there a for sure way to tell that the distributor is in the correct position. when I installed it I thought I had it pointing to the number one cylinder but now that I thing about it I might have had it pointed more to the front.

Oops forgot to ask. If I get the thing timed correctly could that be the popping I am hearing rather than it being a lean condition or the timing itself creating a lean condition? Just curious since EdleBrock claims there is little to no adjustment right out of the box. I find that a little hard to believe because of all the engine combos and altitude changes. Ok now this is a really wild shot and maybe I shouldnt even mention this but if I am off a tooth and you say try setting initial timing to 40* does that number come close to working out because of the way the 8 terminals on the cap in a 360* circle make them 45* apart being off one if I take my 8* intitial and add 45* making it 53* would that give me actually 8* of initial timing? Just a brain fart that came out of knowwhere probably not even close to being right but I thought I would mention it anyway.

[quote="75 V8LUV"] I didnt think it would matter if it was off a tooth as long as the number one spot on the cap lined up with the rotor and then the timing light reading off the #1 plug wire.

You are correct there the distributor does not care where it points .

If you moves the metering rod and it helped it sounds lean . Make sure you have enough fuel from the idle circuit . If it is lean than the accelerator pump can't compinsate and you will lean pop or stumble . Metering rods and jets are for cruise and power . Does it back fire just going down the road ? What about full throttle ? Or just as you accelerate ?

Sounds lean to me. What do the plugs look like? Are they coming out white? Maybe you have a bad vacuum leak?

I confirmed the part about the distributor not caring where it points the other day after talking with my father in law. He also said he didnt do anything abnormal with the cam when it was put back in. As far as the idle circuit goes that is controlled from the two idle mixture screws on the front of the carb right? Now if that is the case I adjusted them like the owners manual described doesnt mean I did it right so that is a possible issue. After adjusting the accelerator pump and switching metering rods I did notice a giant improvement. Its not 100% though, It seems like in the lower RPM range while cruising it gets a little slight popping but if you are cruising down the road and its turning like 3000 RPM I dont notice it as much or at all. Now go from cruise to WOT and it gets a slight hessitate and sometimes a pop. ALso after talking with the fatherinlaw he asked me if I might have overtightend the valves when I was adjusting them. I adjusted the valves with the motor not running so Im thinking maybe what I call zero lash is different from who ever invented the term and the extra 1/4 turn was too much. Also too many years of operating the jack hammer has damaged my hearing slightly and with the loud exhuast of the truck I sometimes have a hard time picking up on what it is doing. My next step is adjusting the valves while it is running. Sometimes I wish I would have kept the LUV I had it all dialed in.

Lifters are probably too tight.

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FIAA!

SFPP!

You hit it right on the head. I adjusted the valves with the engine running today. First thing I did was button it up and take it for a drive. before I even pulled out of the garage I noticed it sounded 100% better got it down the road to the stop sign and got on the gas like I normally would have on other test drives and did a pretty impressive burn out. I should say I was impressed the guy that lives on the corner was a little upset about it though. So I continued along with my drive never heard any popping or felt any flat spots what so ever. I think tomorrow I will try changing the metering rods and accelerator pump back to the way it came and try adjusting the timing back where it should be.

Ok I have a stupid question that is off topic but how much lift can you safely throw at a set of sbc heads that have press in rocker arm studs?

If you are looking for the cheap route get the studs pinned. I have pulled a stud with stock rockers and a .495 lift cam. With roller rockers I am sure you can run more.

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Money can't buy happiness, but it can buy horsepower...and that's kind of the same thing...

It's not the lift that is the problem it is the valve spring pressure that becomes the problem.

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1978 pro street step/side 455Buick, 4sp,4.11s, 31/18.5s

well eventually I was thinking about the Edlebrock RPM cam but probably going to get a better set of heads first.