Chris`s85Z28

I just put my 305 back in my Z28 after a rebuild and now I`m trying to start her for the 1/2h break in but it won`t start I even had my Q-jet on fire because it back fired so hard. It`s gotta be timming, I thought I put the 1 cyl. at TDC and I pointed the rotor to the 1st cyl. Maybe the 1st cyl was at BTDC ???? how do I check to see if the distributer is pointing to the 1st cyl at TDC???.

Revolutionary

Pop out the number 1 spark plug and turn the engine over to tdc with your finger over the hole or a compression gauge on it to make sure you are on the compression stroke. If you are sure you are on the compression stroke then stop the crank at just a few degrees before TDC and drop in the distributor. The rotor should be pointing toward the number one cylinder roughly and the HEI plug in should be facing straight at the drivers fender. Fire it up now and set timing.

trackbird

I'm too lazy for that. I just pull the distributor, spin the rotor 1/2 turn and drop it back in.

If you were real careful to keep the timing chain dots lined up while you installed the motor, you are 180 degrees out on your timing. When both dots are at 12 o'clock you are on cylinder 1, when the dots are "matched up" at 12 and 6 (like for a cam install) you are firing the #6 cylinder and the distributor will be 180 degrees off if you install it on cylinder 1. I learned this after doing it wrong the first 3 times I rebuilt a motor. I kept it lined up and it was always 180 out. After a little research, I found out what I just told you.

Good luck.

Chris`s85Z28

Thanx guys, I`ll try to fix it tomorrow, I thought it was 180* out .Well this is the 1st time I`ve ever done this. I`ll let you know how she goes tomorrow.

92RS305#2

lots of people seem to end up 180* off on timing, is there a reason why this happens or is it just a 50/50 chance to get it right/wrong??

trackbird

It is because everyone is very careful to keep those dots lined up, which is the #6 firing stroke and not #1.

Pneumatic_Tire

yeah I made the mistake of thinking if I had the timing marks lined up, that the number 1 cylinder was at TDC. Did the finger to number 1 cylinder with the spark plug out and got it dead on. Good luck!


P.S. Don't get distressed, there are always gonna be bugs to work out when you rebuild an engine, especially your first.

Chris`s85Z28

Guess What I lined the distibuter with the #1 cyl, at TDC and she STILL WILL NOT START, WTF I`ve checked everything 5 times, I have fuel and spark, The firing oder is right I checked it a billion times I even backed off the rockers thinking I tightened the rockers too much I think it helped but when I try to start it all it dose is flood out I had gas jumping out of the carb when it back fired, I HAVE NO IDEA WHAT THE HELL IS WRONG. If you have ANY idea what is wrong please tell me because I have no clue

trackbird

How did you verify that cylinder #1 was on the firing stroke?

Chris`s85Z28

I put my finger over the #1 cyl and I had the engine bumped till the compression pushed my finger away and the timming mark on the balincer was lined up with the 0* mark on the timming tab. I pointed the rotor to the #1 cyl.

Thats right, right???

Pneumatic_Tire

Check to make sure the fuel pressure it at spec, and play around with the rocker arms again. When you try to start it, does it sound like a normal engine trying to start, or does it just sound like a constant non pitch changing whine? In other words can you hear the compression building up? Know what I mean? I can't figure out a better way to describe what I am saying.

Chris`s85Z28

I have no idea how to check the peressure on a carb. what I do know is last year the pump worked fine and it`s delivering more than enough gas.

As for the starting sound as it`s turning over you can hear it try to start then it backfires. and yes you can hear the comperession build and you can hear it suck the air in (man those rings work good) one time I almost had it started I was trying to start it I had the gas to the floor then she started to spin faster and you could hear her almost start then it backfired again I`m going back out to try in the morning

Pneumatic_Tire

Hmm, ok. Sounds like it's on the verge. Try using a spark tester and check every cylinder.

A friend of mine just rebuilt a 305 for his Caprice, and he has had similar problems. He's had to screw around with the rocker arms, timing, and carb idle mixture, but he got it running nice.

Chris`s85Z28

Well I`m about to give up and park that POS. I think I burnt out the starter and the battery is dead and no matter what I do she just shoots flames out the carb, I even changed carbs and the same thing happened. I had it just about started and then the carb cought on fire YAY!!!.

Chris`s85Z28

Holly **** she started the valves were hung up so I reajusted the Valves and she fired right up Oh man I can FEEL the power she has ALOT more then she did before the rebuild I can tell ya that I can`t wait to drive her!!!!!!!!!!!! Now I just need to fix the clutch and take her for a spin Thanx for your help guys.