question about dizzy and timing...PLEASE HELP

you do realize that you also have to set the timing with the spout out even after you swap out the distributor?? go to autozone and rent or buy a timing light and set your timing with the spout out to 10 * BTC after you set the distributor down on the correct tooth.

also, unlike that article, I dont use the finger/air method to get the piston to TDC, I put a screwdriver in the cylinder so I can physically feel the piston come up to the top and then when it pauses at top, I know it's at TDC.

I have replaced my dizzy two times and each time I have no idea what tooth it was on or how it was stabbed. I have read before that there is no such thing as off by a tooth, it is only a timing issue. Before I took the old one out, I marked the position using a marker, then matched the position with the new one. Then I used a timing light to set things right. I have no idea about TDC, just looked at my balancer and marked 10 degrees BTC and it was easy. Time it with the spout out because the computer will take over when you put it back in.

Again, perhaps someone else can confirm...there is no such thing as one tooth off....you only need to turn the distributor until the timing is right....if it is off by a tooth that only means rotate the distributor a little more.

I had to install a new balancer to get timing right because all the marks were rusted and faded.

if it won't run over 4000 rpm it sounds to me like you spout is still out. being 1 tooth off only applies to those dizzys where travel is limited by a stop. 5.0's don't fall into that catagory. some people set everything at 0 first (engine @ tdc and rotor at #1). then they use a timing light to set the advance. Others will place the engine at 10btdc and rotor at #1then use the timing light to verify

95BEASTstang said:

When you get the piston on the compression stroke ,don't you just put the timing indicator to 0* on the balancer?That's how I have been finding TDC. If that's the wrong way maybe that's my problem.

But as far as setting the timing with the spout out and a timing light ,yes I know how to do that but even when it's set to 10* it still feels like it runs sluggish,and that's why I think i'm one tooth off when I stab the dizzy.

Thanks for the input,maybe I will try the screwdriver method and see if my balancer is off...

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yeah you could be 180 out or the outer ring on the balancer could have slipped. I had that happen once without realizing as it only slipped side/side and didnt move forward or backward off the center ring any so I couldnt tell and I just could NOT get the timing right haha.

In a perfect world

It is true ... you can't off by one tooth

In a world of reality

Plug wires could be not long enough to allow you to twist the dizzy enough
or
Maybe some kind of mechanical obstruction prevents enough adjustment
or
Other similar circumstances could cause such issues

So having said that ............

The one tooth off phrase ...

Its all about the original installation location
or you might say
A reference point of how the dizzy was ........
which allows maximum dizzy adjustment in both directions

Honestly if the hb mark is lined up to tdc and the rotor is pointing to #1

Its gonna be ... On the money OR 180 out

If it fires right up ... you are good to go

If it fires but backfires or revs up very slowly ... just flip the rotor 180

Hope that helps clear things up a bit

Grady

Wise thoughts by Grady and others about the one-tooth idea.

The indexing for the PIP is the most important aspect of it IMHO.

Ummmm.....if you can't rotate the dizzy because of wire issues, then obviously you have to pull and reposition it....duh!! However, if your timing is right and things still run like crap, then there is something else going on besides "off by a tooth".....In my experience anyway.

If you think you have an exhaust restriction, you can connect a vac gauge. Hold the RPMs at 2500 and watch the reading. If it starts to drop off after 20-30 seconds, that suggests a restriction.

Not a stupid question. It simply gets connected to manifold vacuum source. You could use tee in at the vacuum tree for instance.

If you have a friend who is a mechanic, they do have tools for measuring backpressure or doing a pressure differential before and after the cat. Most of us dont have such tools so the vac test is a good place to start.

Good luck.

curious if maybe your coil is arcing to itself which would cause high rpm stuttering.

look for a white spot on it around the metal ring or look for blue light arcs in a dark lit area when revving the engine from under the hood. sometimes it will only arc under load though.

Did you reset your idle and TPS voltage after changing you TPS and IAC? If not then try this:

Begin with a cold vehicle. The idea here is to get the car to a firm cold idle with enough air bleed capacity left in the idle circuit for IAC adjustment.

The idle stop should be set first. Back out the idle stop screw, away from the bell crank arm, until about 1/2 turn past the point where it no longer makes contact (blade fully closed). Using a 0.010" feeler gauge, tighten until gauge just drags between screw and bell crank arm. Remove feeler gauge. Tighten screw exactly 1 1/2 turns. If the screw is very loose, put a drop of loc-tite or silicone on it, so it doesn't work out of adjustment.

Now remove the connector to the Idle Air Controller (IAC) just on the other side of the throttle body. Start the car and allow vehicle to warm for 2 minutes. Give a small "blip" to let it settle. If it is having a hard time staying running you may have to get an assistant until you can get to the front of the car. Now open or close the air bleed screw (CCW opens) next to the IAC until the car idles at 575 to 600 rpm. For guys with aftermarket cams and an EEC tuner, you might want to idle a bit more briskly, say 650 to 675.

Obviously, this rpm range is by what the car and driver wants...IE, no set idle speed, whatever works for YOU.

Turn off the car. Now count the number of turns clockwise to close on the idle air bleed screw. If it falls between 1/2 and 2, it's okay, now reverse it out the same number of turns. Log the number somewhere in case you need it for the future. Reconnect the IAC. You are done.

If the air bleed screw is above 2 turns, it's a good idea to tighten the idle stop screw another 1/2 turn, and then repeat the idle setting. If it is below 1/2 turn, then loosen the idle stop screw by 1/4 to 1/2 a turn, and repeat the idle setting. Be sure to put another drop of silicone RTV on the stop screw if it was disturbed. Reconnect the IAC.

Now remember we adjusted the set screw on the throttle body. That means that the voltage reading from the TPS sensor has changed. It should read between .96 and .99 volts. Anything outside of that range will cause all sorts of issues including misfires and rough idle.

you will have to back probe the TPS connector. With the connector attached to the TPS stick a paper clip into the rubber boot on the connector where the top and middle wires go into the connector. The rubber is very flexible the paper clip will slide in between the rubber and the wire.

Set your multimeter to volts. Turn ignition to ON. Then place your multimeter leads on the metal pins. If it comes up as a negative that is okay as long as you are -.96 to -.99. If you get this reading then great you are done and hopefully your issues are gone. If not proceed to step 9

This is where and extra pair of hands come in handy. Using a large screw driver you will need to loosen the bolts that hold the TPS. DO NOT USE A SCREWDRIVER THAT IS TOO SMALL BECAUSE YOU WILL STRIP THE BOLTS. They probably will be really tight so you have to really lean on the screwdriver and use some finesse.

Once the bolts are loose you will need to move the TPS up or down and continue to read the voltage. Once you get it to the desired setting you can retighten the bolts. What I do is I find .97 and then as carefully as possible I tighten the TPS down. what will happen is the voltage will change usually to .96 or .98 but that it okay. Once you are done with this manually open the throttle body a few times and close it then reread the voltage and make sure it is still within our desired range.

Depending upon how loose your set screw was you might want to cover it in RTV to hold your setting. At this point you have CORRECTLY reset you idle.

95BEASTstang said:

Sorry for the long post ,I just miss my car running like it did before i removed my dizzy...Any help would be appreciated....Thanks in advance....

Click to expand...

If the current issue started after swapping the reman'd dizzy in, go back and check the things you initially touched during the install.

Note that you might have a bad PIP in your current dizzy. If the PIP tests ok upon taking in the core, it's often left in place. If you see an extra hole in the dizzy shaft, that indicates they changed the PIP (it takes too long for them to realign the holes so they drill a new one).