i have a 1986 camaro with a 350 that i rebuilt its timed and everything but i cant get it to fire up. its got fuel and spark i dont know what else it could be. can anyone help me?
the advance springs maybe. WAG
maybe the screen name says it all?
is that mr skeez?
Are you sure that you have it timed right? Because you just need fuel, spark, and air, so if you’ve got those coming together at the right time in the right quantity, you’ve got a running motor.
Are you sure that your cam timing is correct?
how do i check that because my dad helped me rebuild it and he said we did that but i dont think we did. so how do i check that?
You will have to get to the timing chain and see if th marks line up as per specs. Sorry to tell you, but it is GTO time. (get you tool out)
i know the marks on the gears lined up. but does that really mean its in time
lets not forget EXHAST.
Before you go tearing in to the engine, make sure that you have the ignition timing right. Pull the number one spark plug and put your thumb over the hole. Then have someone turn the motor over with a breaker bar. When you feel the compression starting to push your thumb off of the hole, have your assistant slow down and turn until the line on the harmonic balancer is lined up with the 0-degree mark on the timing pointer. This is top dead center for the first cylinder (where you want your initial timing).
Now you need to find the first spark plug wire on your distributor and look under the cap. The rotor has to be pointing toward (and I mean almost exactly toward) the number one spark plug connector on the distributor cap.
I have to say, when I hear of people putting engines back together (even people who are pretty handy with turning a wrench) I think this is one of the most common problems. I’ve done it twice myself.
If you just can’t get it to run or if you don’t feel compression as the top dead center line is coming around, then you’re going to have to pull the balancer, water pump, and timing cover and make sure that you’ve got it timed right. At one point for every two revolutions of the crank gear, the dot on the cam gear and the dot on the crank gear have to line up (and I mean, they have to be pointing directly at each other).
Do you know how to break-in the cam and everything, once you get it fired? That’s probably the most important thing you’ve got to do next.
If the marks on the timing gears are aligned correctly the camshaft is correctly timed. That means that the valves are correctly timed and opening at the correct time with respect to the piston position.
It says nothing at all about ignition timing. That’s done separately. Check THAT timing as Josh has described above. That should get you pretty close.
One of the oddest and not really funny non-running engines after rebuild was due to a lack of compression,and someone not really knowing what they were doing.
350 was rebuilt fired up immediatly then died after about 5secs.
To make a long story short, I was busy on the day my friend wanted to finish his engine so he took on the project himself.
This guy wanted things to look really nice so he sand (not really sand)blasted the heads so they would paint nice,they looked fabulous.
Well he didn’t get the blast material out of the ports and put the heads on, as soon as the engine fired it pulled all that material in and the result was no-compression.
At the time we didn’t know why the engine lost compression but we pumped oil in the cylinders and it fired back up.
That engine lasted about 90 days,upon disassembly every bearing was gone including the cam bearings.
Do you have compression?
every thing has been done.its in time it has compression. did the whole finger over hole every thing. the last thing is maybe the rockers arent tight enough i dont have a gauge to check for that. every thing in and on the motor is new
When you did the initial tappet adjustment, did you turn the engine and check every one about four times? If you can’t spin the pushrods when the valves are closed, the valves may be open all the time. If there is too much clearance, some of the pushrods may have fallen out. The EGR valve may be stuck open. Are the number 5 and 7 plug wires on the wrong plugs? Is the center electrode on the rotor bent to one side?
the plug wires are on the right plugs. when i first put it together the rockers were over tight so i changed the valves just 2 be safe. and then i went from there. and did it over again but i think the rockers arent tight enough. i just put 2 much money in this motor to just junk it.
Time to put a compression gauge on it.
Take all the plugs out, throttle wide open, measure all cylinders and post back with the results.
the cars got enough compression my batter and starter can barely keep up
When you’re trying to start the motor do you get any reaction at all?
When turning the motor over on the starter, do you get a crisp BLUE spark if you hold a plug wire about a quarter inch away from a good ground? Does the engine try to kick, backfire, anything?
I assume the plugs are wet and getting fuel and you have good spark to the plugs. If you are sure the ignition timing is correct and not 180 out then you might try this trick. Mark the present position of the distributor and then loosen it so you can adjust it while the engine is cranking. If the problem is just due to a slight timing problem you will be able to get it going that way.
how am i able to tell if its 180 out
When you did the compression test with your finger on #1 cylinder did you check to see if the rotor was pointing to that plug wire position? That is how you tell.
One other thought on this, do you have the plug wires going to the correct positions in the cap and are they in the direction the rotor turns?