SOLVED: Still running poorly, still having vacuum issues
- Thread starter cfmustang
- Start date
so have you still not hooked up the vac advance and retimed?
Nope. Had to verify the TDC mark first, which I just did and great googly-moogly you guys were right!
When all is said and done, my damper has slipped a total of 10 degrees to the right to TDC! I couldn't believe it so I double checked it! 10 degrees!
So I marked the new TDC mark, started it up and let it warm up. Once I hooked the timing light to it and checked the new mark I am running at 3 degrees before TDC!
Jimbo, you were right on the money!
I have people coming over in a few minutes so I couldn't retime and adjust the carb, but I have a few questions;
1) Does it matter if it was on the compression stroke or the exhaust stroke. When I was done, I popped the dizzy cap and noticed the rotor pointing to the number six plug wire. I think it is still allright, isn't it?
2) Even at three degrees, the vacuum advanec canister is bumping into the dipstick, so I can't really advance it any more. To get it to 12 - 15, it will be pointing straight at the engine.
3) Now that I know I am at three degrees, how come it was pinging at 4 or five degrees?
When all is said and done, my damper has slipped a total of 10 degrees to the right to TDC! I couldn't believe it so I double checked it! 10 degrees!
So I marked the new TDC mark, started it up and let it warm up. Once I hooked the timing light to it and checked the new mark I am running at 3 degrees before TDC!
Jimbo, you were right on the money!
I have people coming over in a few minutes so I couldn't retime and adjust the carb, but I have a few questions;
1) Does it matter if it was on the compression stroke or the exhaust stroke. When I was done, I popped the dizzy cap and noticed the rotor pointing to the number six plug wire. I think it is still allright, isn't it?
2) Even at three degrees, the vacuum advanec canister is bumping into the dipstick, so I can't really advance it any more. To get it to 12 - 15, it will be pointing straight at the engine.
3) Now that I know I am at three degrees, how come it was pinging at 4 or five degrees?
OK, you say the balancer has slipped to the right. That's not what I'd have expected, but:
When you look at the balancer from the front of your car, is the new, correct mark to the left of the factory's notch?
If it is, then in fact you were firing at 20° BTDC. That's why it was pinging! The fire was lighting well before your piston was near the top. Draw a little schematic if it helps you understand what's going on.
Regards, Adam.
When you look at the balancer from the front of your car, is the new, correct mark to the left of the factory's notch?
If it is, then in fact you were firing at 20° BTDC. That's why it was pinging! The fire was lighting well before your piston was near the top. Draw a little schematic if it helps you understand what's going on.
Regards, Adam.
Either compression stroke or exhaust stroke is ok in this case.
You may need to move your distributor one tooth. Pull the distributor out just far enough to allow you to turn the rotor shaft slightly, then drop it back in. That should allow plenty of adjustment.
Joe
You may need to move your distributor one tooth. Pull the distributor out just far enough to allow you to turn the rotor shaft slightly, then drop it back in. That should allow plenty of adjustment.
Joe
Mark P said something very important. Check the distributor cap. Aftermarket ones are indexed wrongly in many cases, and fail to allow the right idle timing to be set up. Find an old stock one, and see if there is a difference. Please.
Go again through Jimbo 65's advice.
The other thing. I'd expect to get 160 psi of compression, not 145 psi. After you've checked things through, I'd suggest advancing the cam timing.
You are doing fine, and you will get things worked out.
We are proud of you!
Deano
Go again through Jimbo 65's advice.
The other thing. I'd expect to get 160 psi of compression, not 145 psi. After you've checked things through, I'd suggest advancing the cam timing.
You are doing fine, and you will get things worked out.
We are proud of you!
Deano
A
Anonymous
Guest
The old fashioned "poor mans" way to get more distributor movement is to line up a cap termial with some sort of visual reference on the engine, rotate the distributor to the next terminal, then switch all the wires over one terminal.
If that sounds too complex to understand, then forget it.
If that sounds too complex to understand, then forget it.
I think that is more of the lazy mans way to do things 
but it is also a good way to do a quick test of things
but it is also a good way to do a quick test of thingsSorry, I may have spoken incorrectly about which way it had slipped. It has slipped to the left. When you are at the front of the engine, the new TDC mark is 10 degrees to the right of the original mark. That what I get for trying to use terms I don't exactly understand...yet.
My thought, and I am probably way off, is that the pinging with the timing that far retarded has something to do with the fact that I have been trying to tune my carb at essentually 0 degrees with vacuum so low that mixture is completely off. That is why a vacuum leak was causing it to actually run better.
I didn't have time or the second person I needed to recheck the compression. I could try my wife, but lately she feels the Mustang has become her nemesis. However, my brother-in-law is coming over this afternoon and I was planning to have him help me reverify the compression.
I tried moving the dizzy one tooth before and once I got it out it took me about an hour to get it back in all the way, and then I think I had to drop it back where it was. It would go down, but not all the way unless it was at exactly the right spot.
What direction would I want to turn it?
Linc, I remember reading something like that in Jimbo's post. Are you talking about spining the entire cap or just reindexing the plug wires?
Currently it is:
__6_
3___2
5___4
__1_
I am assuming it would be:
__3
5___6
1___2
__4
Is that correct?
My thought, and I am probably way off, is that the pinging with the timing that far retarded has something to do with the fact that I have been trying to tune my carb at essentually 0 degrees with vacuum so low that mixture is completely off. That is why a vacuum leak was causing it to actually run better.
I didn't have time or the second person I needed to recheck the compression. I could try my wife, but lately she feels the Mustang has become her nemesis. However, my brother-in-law is coming over this afternoon and I was planning to have him help me reverify the compression.
I tried moving the dizzy one tooth before and once I got it out it took me about an hour to get it back in all the way, and then I think I had to drop it back where it was. It would go down, but not all the way unless it was at exactly the right spot.
What direction would I want to turn it?
Linc, I remember reading something like that in Jimbo's post. Are you talking about spining the entire cap or just reindexing the plug wires?
Currently it is:
__6_
3___2
5___4
__1_
I am assuming it would be:
__3
5___6
1___2
__4
Is that correct?
Well, I knew I should be cautiously optimistic.
After a lot of tries, fiddling and cursing, I was able to get the dizzy over one tooth where it belonged so I could set it to 15 degrees. Man, once you pull that thing it is nearly impossible to get it back in all the way.
Anyway, it idles better but is still not all the way there. In fact, I can't tell if there is a miss or it is just surging a bit.
I hooked my vac pump to the manifold vacuum and it is flickering back and forth between 12 and 7, several times a second. Shouldn't it be a steady reading. Bumping the timing to 20 degrees doesn't seem to help.
I am able to back the idle screw out some since vacuum is a little better, but it still is in about 4-5 turns. Weber says it should be no more than 2.
Taking it out for a ride, the pickup is a bit better and I am not in danger of stalling at a stop light anymore, but the engine still is shaky. It was also pinging really bad at partial throttle. The vac advance is still disconnected and plugged for the time being. I don't have a dial back timing light, so I am not sure exactly how high it jumps to, but with it connected it seemed like the itial timing was above 20 degrees and it actually seemed to hurt the idle some.
This did, however, solve the overheating problem! So at least I have that going for me.
I see that I am going to have to recurve the dizzy to solve the pingingbut does anybody know why my vacuum is low and fluctuating so much? That seems to be why I can't finish getting the carb tuned.
After a lot of tries, fiddling and cursing, I was able to get the dizzy over one tooth where it belonged so I could set it to 15 degrees. Man, once you pull that thing it is nearly impossible to get it back in all the way.
Anyway, it idles better but is still not all the way there. In fact, I can't tell if there is a miss or it is just surging a bit.
I hooked my vac pump to the manifold vacuum and it is flickering back and forth between 12 and 7, several times a second. Shouldn't it be a steady reading. Bumping the timing to 20 degrees doesn't seem to help.
I am able to back the idle screw out some since vacuum is a little better, but it still is in about 4-5 turns. Weber says it should be no more than 2.
Taking it out for a ride, the pickup is a bit better and I am not in danger of stalling at a stop light anymore, but the engine still is shaky. It was also pinging really bad at partial throttle. The vac advance is still disconnected and plugged for the time being. I don't have a dial back timing light, so I am not sure exactly how high it jumps to, but with it connected it seemed like the itial timing was above 20 degrees and it actually seemed to hurt the idle some.
This did, however, solve the overheating problem! So at least I have that going for me.
I see that I am going to have to recurve the dizzy to solve the pingingbut does anybody know why my vacuum is low and fluctuating so much? That seems to be why I can't finish getting the carb tuned.
Glad to hear that the overheating problem is better 
#1) Check for a valve maybe adjusted too tight
#2) A dial-back is nice but us poor folks just mark the timing pulley in five degree increments up to about 45 degrees. White tape with carefuly inked markings works fine. Then use the regular timing light.
#3) Before going to all the trouble of re-curving, please try setting the timing to stock specs or wherever it gives you about 35 degrees revved up, then hook up the vacuum advance to manifold vacuum. You may be pleasantly surprised.
#4) The pulsing vacuum problem needs to be fixed before any timing trickery will help much.
Joe
#1) Check for a valve maybe adjusted too tight
#2) A dial-back is nice but us poor folks just mark the timing pulley in five degree increments up to about 45 degrees. White tape with carefuly inked markings works fine. Then use the regular timing light.
#3) Before going to all the trouble of re-curving, please try setting the timing to stock specs or wherever it gives you about 35 degrees revved up, then hook up the vacuum advance to manifold vacuum. You may be pleasantly surprised.
#4) The pulsing vacuum problem needs to be fixed before any timing trickery will help much.
Joe
Would the valve cause the fluctuating vacuum? How do I check for the cause? Would late valve timing cause the vacuum issue? What would cause the late valve timing? The improperly timed cam has been mentioned?
Checking that sounds like it is well beyond my abilities. I am starting to think that the garage that I paid all that money to screwed me bad.
I fear that I have now reached the end of my abilities to solve this and will have to mothball the car away till I can find a mechanic that actually knows what they are doing and scrape up enough money to get it fixed.
Checking that sounds like it is well beyond my abilities. I am starting to think that the garage that I paid all that money to screwed me bad.
I fear that I have now reached the end of my abilities to solve this and will have to mothball the car away till I can find a mechanic that actually knows what they are doing and scrape up enough money to get it fixed.
A
Anonymous
Guest
cfmustang":2m5wjwmr said:
You just need some more talented friends!!!
Sorry.
I didn't mean to sound like a 5 year old, its just that I thought I had it and after a whole afternoon under the hood I am still having problems. It just gets you down.
Is a sticky valve caused by misadjusted rocker arm assembly? I am not sure which one I have, but I remember that when we rebuilt the engine 10 years ago, we got whatever adjustable rocker arms assembly that Clifford sold at the time.
What about the late valve timing?
I didn't mean to sound like a 5 year old, its just that I thought I had it and after a whole afternoon under the hood I am still having problems. It just gets you down.
Is a sticky valve caused by misadjusted rocker arm assembly? I am not sure which one I have, but I remember that when we rebuilt the engine 10 years ago, we got whatever adjustable rocker arms assembly that Clifford sold at the time.
What about the late valve timing?
A
Anonymous
Guest
I doubt you have late valve timing unless the timing chain has stretched A BUNCH.
Since you DO have adjustable rockers, and it has been TEN YEARS, it would be prudent to pull the valve cover and adjust them proper once again.
Since you DO have adjustable rockers, and it has been TEN YEARS, it would be prudent to pull the valve cover and adjust them proper once again.
With that cam you may never get above 13-14" on the vacuum gauge. And it probalby is going to be lopey with the gauge fluctuatuing all over the place, especially if you're trying to get a low idle. How fast is it running at idle?
