Distributor.. Bad or jumped a tooth?

[deputy865]

It never ends!!! lol..

1991 3SGTE

As most of you know, I've been having some major issues with my car recently with it not pulling enough vacuum even after all of my leaks have been taken care of.

So I decided to mess with the distributor to try to provoke some better vacuum numbers.

First off, my distributor was turned counter-clockwise as far as it could go, I later searched and found out that meant the timing was retarded fully. I bridge TE1 and E1 and got to work. I loosened the bolts, and started turning it clockwise.. The car got better and better the more I turned it and now has great throttle response and it was also pulling more and more vacuum. I now found myself fully advanced in my ignition timing, but still not pulling enough vacuum.. I drove around my yard with it like this, but even I knew having my timing fully advanced was bad. I turned the dizzy back to about a center point between the two.

So I'm still not pulling enough vacuum, and I'm afraid that when I do the timing correctly with a timing light, its still not going to pull enough. So does that mean:

Bad distributor?
Distributor jumped a tooth?

My plugs and wires are brand new as well as my distributor cap and rotor. Compression is perfect across the board and cam timing is where it should be.

Shane

[toyotaspeed90]

you didn't mention what kind of MR2 you have...

if it's a 5sfe... then the dizzy is keyed.... it CAN'T be installed correctly.

if it's a 4age/gze... then the dizzy won't jump a tooth... it's directly meshed with the exhaust cam gear. What CAN happen is the timing belt can get old/loose/worn... and jump a tooth....

check your cam timing....

[deputy865]

Originally Posted by toyotaspeed90

you didn't mention what kind of MR2 you have...

if it's a 5sfe... then the dizzy is keyed.... it CAN'T be installed correctly.

if it's a 4age/gze... then the dizzy won't jump a tooth... it's directly meshed with the exhaust cam gear. What CAN happen is the timing belt can get old/loose/worn... and jump a tooth....

check your cam timing....

Edited.

1991 3SGTE

Timing belt appears to be brand new and still taunt. Cams line up in their correct spots at top dead center, so I can say that cam timing is on. Also, I have near perfect compression across the board. Every, and I mean every, vacuum leak has been assessed and fixed.

Messing with the distributor is the only thing that has shown me positive results.

Shane

[toyotaspeed90]

it's not physically possible for the dizzy to jump a tooth unless something seriously bad happened.

it's possible that since you have a 91.... that the connections on the dizzy or the coil/ignitor are bad.... and when you adjust it you're moving the wires.....

check the wiring

[MR2Jedi]

Yes, my distributor wires were so brittle, 3 of the 4 just snapped clean thru one day when I was removing the dizzy.
But you really need to put a timing light to the engine to know exactly where you are.Needs to be 10 degrees BTDC with TE1 and E1 cross connected. then it should be 10-17 degrees BTDC with out the cross connection.