Ticeblue

Ok need help determining if my cam is a degree off or not....I can't get the car to run. I've checked everything except for the cam being a degree off. How can you check this, I have heard there is two dots that are suppose to line up or something the previous owner said the motor had a mild cam in it before he passed away so I have no source of history...


Please help and thank you in advance...would like to get it running to make it to the third gen meet in may with all the Texas people!!

built91Z28

Yes, there is a dot on the crank gear and one on the cam that need to line up.

Have you done a compression check? Does the motor turn over good by hand and does it feel like any valves are touching pistons?

Ticeblue

Well it's hard a crap to turn by hand/breaker bar and I haven't torn the heads off but the motor ran about 2 years ago before the owner got sick, which also the owner said it was 10.5 compression. Oh and it's got a carb on it (670 holley street avenger) that might matter or not..

The valves do not sound like they are hitting, I guess I need to take the water pump off and timing chain and check the dots or is there an easier way to do this??


Thanks by the way!!

built91Z28

A compression check can kinda help to tell you if the cam is off. Your numbers would probably be very low, or very high. Just having low or high numbers though doesnt mean its the cam, it just opens the possibility of it being the cam timing.

However, if it ran before, then I wouldnt think its the cam timing. Even if it is off, it is good enough that it use to run, so no reason it shouldnt now. My main concern would be that you said the motor is very hard to turn over by hand. A motor shouldnt be easy to turn, but shouldnt be very hard either. Although everyones idea of very hard is different, so this may or may not mean something.

Pull all the plugs out and then turn it over by hand. Is it easier?

In another post you made, you said the motor does run, but the headers glow in under a minute. Did the motor stop running? Have you verified timing with a light when it was running? It could be a tuning issue in the carb. Does it sound like it wants to start?

camaronewbie

taking the spark plugs out will allow you to turn it by hand - it's hard to turn a motor by hand with plugs in it.

I'd avoid removing the timing chain cover if I could - real PITA. You have to remove dist cap and rotor button, remove the motor mount bolts, remove the tranny crossmember bolts, and jack up the motor some to reseal all that - the oil pan and timing chain cover inter-connect, and thus doing a timing chain cover removal neccessitates removing the oil pan and replacing that gasket as well.

If the motor ever ran before, it's highly unlikely that cam degree is your problem.

AND - even if the cam is off by a tooth - all that can be adjusted with changing the timing at the distributor.

Where do you have the base timing set at? You should be trying to start the car with the base timing set at 10* BTDC minimum, and advancing it a degree each time you try (up to about 20), until it fires.

Ticeblue

The car will turn over (crank) but will not fire(start/run)....I get confused with which way to turn the dist to advance it, I should turn it counter clockwise if I'm standing at the front of the car to advance it correct to BTDC??? I've forgotten how to work on these things it's been so long...thanks for the help I will report back tonight when I get home and do it

LB9GTA

iTrader: (1)

I had a guy install my cam and it was off by 3 teeth, it ran... like crap... but it ran!

I took the water pump off and the timing chain cover and moved it to the correct mark( my gear had 2 marks on it!)

Then had to notch the timing chain cover to make it fit under the oil pan. It was a crappy job

Guest

The cam being off cant be fixed by adjusting the distributor.

As far as the timing, chances are if it doesnt fire at all then the I'm going to guess the distributor is 180 out. Put the motor at TDC and see which plug wire the rotor is pointing at. It should be either 1 or 6. If it is, then most likely you need to pull the distributor, turn the rotor 180 from where it is, and set the timing from there.

Ticeblue

Ok reporting back.....so all the timing is correct and I can turn the dist. Til the vacuum canister hits the intake manifold but the car will fire off but immediately die and if I turn it back then it just cranks over but won't fire at all....so my question is how can I get the vacuum canister passed the intake manifold so it will fire off and run????? Can I put the plugs in order anywhere on the cap as long as the rotor is on number one??

built91Z28

Just take all the plug wires off and move them in the direction you need the distributor to turn. Just move them over one terminal.

Ticeblue

Don't I have to make sure that #1 is TDC though?? So what you are saying is just leave everything the way it is and just move all plugs over one spot without moving anything else....wouldn't that make the timing off??? Cuz then number 1 cylinder would-be TDC but but the cap would send spark to number 8..... Right ?? Lol omg I think I'm confusing myself,maybe not though....help

camaronewbie

Start at square one - no sense in dicking around trying to avoid the necessary.

1) remove #1 spark plug
2) hold finger in #1 plug hole, and have someone turn motor over by hand until you feel outward pressure on your finger - this is the compresion stroke
3) now rotate engine by hand either direction needed to get the balancer mark lined up on ZERO on the timing tab
4) now, remove dist cap - wherever the rotor points, that needs to be the corresponding terminal on the cap for the #1 plug wire
5) replace #1 plug, run that # 1 plug wire to it
6) follow trest of the wires in the firing order clockwise on the cap
7) have someone run the starter, and with a timing light, turn the dist clockwise to advance timing to about 10 or so, car should fire up and run

InfernalVortex

iTrader: (4)

If the distributor is off a tooth on the cam, then it can be adjusted. If the cam is off a tooth on the timing gear (which seems to be what he's worried about) then it cant be adjusted. Spark timing and valve timing are different things.

However, I agree with the other guys, if it ever ran before the cam is in the correct place. Cams are routinely intentionally installed a few degrees off to change power curves.

Ticeblue

When I say it ran before it's the information I got from the previous owner. Ssince i have owned it the only time it kinda ran is when you leave the starter cranking it will run and you can rev it up but as soon as you let go of either the key or the remote trigger it will die.

Motor was at TDC last and well the rotor is sitting between two posts which are the 1 & 8 it's not directly on a post. On older motors the rotor would sit at 630 correct ? And newer motors sit at about 530ish correct? So is my distributor off maybe...I'm about to just sell this car and start all over

built91Z28

The rotor can point where ever it wants to when at TDC on the compression stroke on cylinder 1. All that matters is that the number 1 plug wire lines up with the rotor. From there you set your timing. Dont give up over what might be a simple timing issue. You could buy another third gen, but your still going to have to set the timing eventually. Once you learn how to, its really no big deal to time a motor from scratch.

Ticeblue

Well if the rotor can point where ever it wants too then I think I will take the distributor out and turn it so I can advance it far enough so the vacuum canister doesn't hit the intake and I can fire this B!*ch up....

I'll just make sure that I'm on the compression stroke on #1 and at TDC before I move the dist.

I think the problem is, is that I'm to smart for my own good and I'm making this into a huge deal when it's me that is the problem...hahaha

Ticeblue

I always had thought that when installing a dist the rotor had to point at 630/530 when #1 is TDC on compression stroke..... But as long as number one is at TDC on compression stroke the rotor can be pointed at 930 and as long as that is where my number one wire is going then should be running.....my brain is starting to smoke a little I can smell it

built91Z28

The distributor doesnt know or care which terminal on the cap is #1. Just as long ast the rotor is basically facing #1 terminal when at TDC on compression on #1, thats all that matters. The only thing that is sometimes a determining factor is plug wire length. If you have any short wires they may just not reach certain terminals, so you may have to have #1 be in a specific place then.

sonjaab

Even IF the cam was off by a tooth/degree and the engine has spark/fuel it would at least backfire or POP thru the carb/TBI/injector or exaust pipe!

Is there spark ??????????
If not either coil or dist. module.

InfernalVortex

iTrader: (4)

I have this friend who constantly thinks his cars are slow because "the timing is off" and is always replacing spark plugs and mucking with the timing. Then he unloads it and gets another piece of crap junkyard camaro and the cycle repeats.

The last iteration of this, he changed the cap/rotor/plug wires and got upset when the rotor wasnt pointing at number 1... took the dizzy out, pointed it at number one, and called me asking why his car wouldnt crank.

Ticeblue

It backfires occasionally through carb. And the whole ignition is new I just got it, msd pro billet dist with vacuum advance, blaster ss coil, and 6al box. I do not plan on getting another "project" third gen. I am going to get one that is actually in great shape. Anyways so when I get home I'll take the dist. out and put number one at TDC again and install the distributor and have it facing number one vicinity and then install cap and run all the wires again.

Ticeblue

Someone needs to live closer to me and come check this crap out, I'd pay for gas and food.....please make me come look like a complete dumb a$$ haha

windowrattler

iTrader: (3)

I'm gonna say your distributor is 180 degrees out of time. While cranking are you able to see the timing mark with a timing light???? Have one person crank while one person finds the mark. If you have spark and fuel you should get something. Are you positive you have both right now?

TNT_Z28

IM GONNA SUGGEST SOMETHING REVOLUTIONARY SIMPLE COMPARED TO WHAT YOU ALL ARE DISCUSSING. CHECK YOUR FIRING ORDER. i could be right or wrong but its caught me off gaurd before. and i had similar results as your describing

18436572... i think i had 3 & 4 crossed and it wouldnt run worth ****

im probably wrong but its easy and fast enough check and you might end up saying what i did, "DUH!"

Guest

Even more indication its 180 out.

InfernalVortex

iTrader: (4)

backfiring through the carb can just be too far advanced too.

1. Bump the car over til you feel the compression stroke on the number 1 spark plug hole. Put your finger over it and hold it as you bump over the car. You'll know. Check the balancer and watch the #1 TDC line come around. Get as close as you can to zero on the timing mark.

2. Line up the rotor with the terminal you're going to use for the number 1 cylinder. Normally this is set to point towards the number 1 cylinder, but as has been mentioned, it doesnt matter which direction it points, as long as it points towards the plug wire going to number 1.

3. Put a mark or a piece of tape on the intake manifold showing where the rotor is pointing (which is where it will point when the motor is at #1 TDC. ) Use that as a gauge to advance and retard the distributor terminal.

4. Double check firing order from there.

5. Turn it over for a second, and see how it sounds and how much itw ants to start. Keep moving the distributor a little to see how it affects it. You should find a range where it will fire and then fine tune from there with a light.

Hard to screw that up.