5.0 Timing Question- help appreciated!
#1
V8 Miata Fan
Thread Starter
5.0 Timing Question- help appreciated!
So I can't for the life of me figure out what's going on with my timing. I pull the spout connector, attempt to set it to 10*, but as I'm moving it to 10* it just sounds like it wants to die. It sounds like it's choking out and grasping for air. The more timing, the happier it is. How can this be? I'm not too familiar with the motor, I just know it's a 93 5.0 with gt40p heads and a gt40 intake. Maybe it's the cam? Maybe the timing chain? I'm stumped. I've done a good bit of googling but can't come up with it. Any ideas or help would be greatly appreciated!
#3
V8 Miata Fan
Thread Starter
#4
V8 Miata Follower
Its normal for the idle to drop way down when pulling out the spout connector. Does it idle back up and run smooth after you plug the spout connector back in? If so, I wouldn't worry about it......
10 degrees base is really low though. I know 10 degrees is factory but I like to run more base than that......
10 degrees base is really low though. I know 10 degrees is factory but I like to run more base than that......
#5
V8 Miata Fan
Thread Starter
Its normal for the idle to drop way down when pulling out the spout connector. Does it idle back up and run smooth after you plug the spout connector back in? If so, I wouldn't worry about it......
10 degrees base is really low though. I know 10 degrees is factory but I like to run more base than that......
10 degrees base is really low though. I know 10 degrees is factory but I like to run more base than that......
#7
V8 Miata Fan
Thread Starter
I don't know much about the motor, but I believe it's getting to be old and tired. But the marks at 0 when its at TDC on cyl 1. So that seems to mean it's not spun.. Or is there something I'm missing?
#8
V8 Miata Follower
If to were me I'd put a new balancer on it, reset timing to TDC, and re-time it.
If you don't want to do that, then I'd keep bumping the timing up until it pings under wide open throttle, then back the timing down 2 degrees and just ride out like that.
If you don't want to do that, then I'd keep bumping the timing up until it pings under wide open throttle, then back the timing down 2 degrees and just ride out like that.
#9
V8 Miata Participant
This may be a totally dumb thing to say, however I was timing a Pontiac 400 a while back and by habit I put the timing light on the front passenger side spark plug (I'm a Ford guy). Same exact kind of issues you point out here. Of course, on the Pontiac 400 number one cylinder is on the driver side (I realized my mistake while on a beer break). Good Grief!
So make sure you have the timing light on number one! Passenger side front cylinder!
So make sure you have the timing light on number one! Passenger side front cylinder!
#10
V8 Miata Fan
Thread Starter
This may be a totally dumb thing to say, however I was timing a Pontiac 400 a while back and by habit I put the timing light on the front passenger side spark plug (I'm a Ford guy). Same exact kind of issues you point out here. Of course, on the Pontiac 400 number one cylinder is on the driver side (I realized my mistake while on a beer break). Good Grief!
So make sure you have the timing light on number one! Passenger side front cylinder!
So make sure you have the timing light on number one! Passenger side front cylinder!
I Think I may pull the balancer and timing belt, reset them with a new one, and try again. I just hate throwing parts at something without an official diagnosis. :/
#11
V8 Miata Habitué
I replaced tps, dizzy, plugs, wires, coil, and found I had plugged injectors. Still wouldn't go right, I had swapped 4 and 5 wires. Also discovered wobbly balancer. Symptoms were different though.
Good luck, you have my sympathy.
Good luck, you have my sympathy.
Last edited by Lateralgeez; 02-28-2016 at 08:24 AM.
#12
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So I can't for the life of me figure out what's going on with my timing. I pull the spout connector, attempt to set it to 10*, but as I'm moving it to 10* it just sounds like it wants to die. It sounds like it's choking out and grasping for air. The more timing, the happier it is. How can this be? I'm not too familiar with the motor, I just know it's a 93 5.0 with gt40p heads and a gt40 intake. Maybe it's the cam? Maybe the timing chain? I'm stumped. I've done a good bit of googling but can't come up with it. Any ideas or help would be greatly appreciated!
Its normal for the idle to drop way down when pulling out the spout connector. Does it idle back up and run smooth after you plug the spout connector back in? If so, I wouldn't worry about it......
10 degrees base is really low though. I know 10 degrees is factory but I like to run more base than that......
10 degrees base is really low though. I know 10 degrees is factory but I like to run more base than that......
#14
V8 Miata Fan
Thread Starter
Unfortunately no :/ I'm replacing the TPS, but I'm not convinced it's going to fix it, but I know it needs to be replaced since one of the wires is barely hanging on. It wants crazy amounts of timing to run "right". Definitely open to more ideas..
#15
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#16
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#17
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Screw in the piston stop, and then rotate the engine until the piston hits the stop, and you can't rotate the engine any more.
Make a mark on the balancer.
Turn the engine the other way until the the piston hits the stop again.
Mark the balancer again.
Exactly half way between these two marks is TDC for that piston.
It's more accurate with a degree wheel. But you can do it with masking tape, a pen, and a ruler.
#18
V8 Miata Fan
Thread Starter
I think I see your problem. This is not how you find TDC. You do need a piston stop. You can buy one, or make one out of a spark plug.
Screw in the piston stop, and then rotate the engine until the piston hits the stop, and you can't rotate the engine any more.
Make a mark on the balancer.
Turn the engine the other way until the the piston hits the stop again.
Mark the balancer again.
Exactly half way between these two marks is TDC for that piston.
It's more accurate with a degree wheel. But you can do it with masking tape, a pen, and a ruler.
Screw in the piston stop, and then rotate the engine until the piston hits the stop, and you can't rotate the engine any more.
Make a mark on the balancer.
Turn the engine the other way until the the piston hits the stop again.
Mark the balancer again.
Exactly half way between these two marks is TDC for that piston.
It's more accurate with a degree wheel. But you can do it with masking tape, a pen, and a ruler.
The motor wants to run at more like 20* ATDC, as opposed to 10*BTDC.
Thanks though, and the more brains on it the better. I'm just really hoping I don't have to pull it all and rebuild...
#19
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Yup, that's close enough.
Pull the valve cover and put a dial indicator on the #1 intake rocker arm. Using a degree wheel, make sure the valve events are happening pretty close to where you want them to. If not, then the cam could be installed wrong. Or it has the wrong firing order. There were a couple of different firing orders for Windsor cams.
Pull the valve cover and put a dial indicator on the #1 intake rocker arm. Using a degree wheel, make sure the valve events are happening pretty close to where you want them to. If not, then the cam could be installed wrong. Or it has the wrong firing order. There were a couple of different firing orders for Windsor cams.
#21
V8 Miata Habitué
Just remembered something that might help! I had TDC on the exhaust stroke instead of the compression stroke. Stuck finger in spark plug hole and turned crank until pressure built up. Then used that TDC to set dizzy.
Now unless you've had the distributor out (I did) then the previous owner would have screwed up. Hopefully you have a way to contact them. Might be helpful. I learned some important things from both the builder and previous owner of my pos lol.
Now unless you've had the distributor out (I did) then the previous owner would have screwed up. Hopefully you have a way to contact them. Might be helpful. I learned some important things from both the builder and previous owner of my pos lol.
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