Engine does not want to start after rebuild-ideas

malcolm;15504 wrote: Im not that familiar with the older models if they were fitted with a CPS (Crank position sensor)?.........if so was it changed?

CIS utilizes ths infamous "green wire" rather than a CPS. How will it do with a whiff of starting fluid? If the balancer were installed backwards and the engine were timed accordingly, you'd likely hear that the engine would spin over as if all 8 spark plugs were removed.

Does not have the sensor - green wire. I may be on to the issue - weak spark. I only have 3v on the no. 1 side of the coil and 5 v on the no. 15 side. I am re- examining the harness and starter to enure it is getting 12 v. Thank you again for the help. Will let you know.

IIRC a weak battery will only supply the starter with sufficient voltage to spin the engine then the ignition system only receives less than optimal power........ensure battery has full charge and indeed recheck all harness connections.

Thanks Malcolm, well the battery is new, I have 12.5 volts on the main starter bolt and with the in the on position I only get 3 volts from the solenoid side of the starter that feeds the coil. This is the OEM starter that worked fine when I took it off. I put it back on because the high torque starter motor I had on there was from 928 motorsports and I thought that the wiring might be the issue. It was not, I have the same condition with both starters.

I also made sure that the voltages from the starter were the same at the resistor which was the 3 volts and on the other side of the resistor - 3 volts. Both starters resulted in the exact same condition.

I have tried a few things. I have 3volts on the 1 side of the coil when cranking and 6 volts on the 15 side of the coil when cranking. I have even bypassed the normal circuit and put 12 volts to the 15 side and no difference in trying to start. Just turns and turns without a hint of attempting to start.

Have run out of ideas.

Back to basics...

Your engine should have two resistors in the primary ignition circuit, one of which is bypassed during starter operation - the system does not run on 12 vdc at the coil.

TDC comes in two flavors - TDC-Compression and TDC-Exhaust.

At the risk of insulting you, I would suggest that you do the following, in the order given, with no short-cuts or assumptions. Doing so should determine whether or not you have an ignition problem.

1) Locate Cylinder #1 - Front cylinder on the right side of the car from the driver's perspective, not from facing the engine.
2) Remove the #1 spark plug. Use a whistle (old-school device - a whistle that fits in the plug hole and whistles when the piston comes up on compression) to determine the compression stroke if you can find one. If you can't find a whistle, you can hold a finger over the plug hole while a helper manually rotates the engine (clockwise or tightening direction) so that you can determine the beginning of the compression stroke. Stop the rotation. Use a long 1/4" wooden dowel or something similar in the plug hole to feel for TDC as a helper slowly turns the crank clockwise. When you get to TDC, check the harmonic dampener to ensure that the pointer is at TDC.
3) When you are certain that you have the crank on TDC-Compression, pull the distributor cap. Mark the distributor body (or mentally note the location) directly under the tip of the rotor button. Then have a helper operate the starter as you watch the rotor, so you are certain of the direction of rotation.
4) Put the distributor cap back on. Determine the plug wire that is directly over the rotor tip location for #1. Physically (not visually) follow that plug wire to its spark plug - It must be the #1 plug.
5) Determine the firing order. (1-3-7-2-6-5-4- Starting at the wire that you have determined is #1, go around the cap in the direction of rotation, and make certain that the next wire in line goes to the next plug in the firing order. (Cylinders 1-2-3-4 back on the right, 5-6-7-8 back on the left) Try to physically follow each wire - it is very, very easy to lose track if you just look at the wires.

When you have completed these steps, it is virtually certain that the ignition timing is approximately correct, and that you can then set it to the exact static advance. You are also now certain that the plug wires are in the correct sequence.

You can get an old spark plug (doesn't have to be a 928 plug - just a spark plug) and open the gap to about 0.080". Put the plug in one of the plug wires, and make sure that the test plug is laying on engine metal, and is not anywhere near a wire harness, and that you can see the plug gap. Watch the gap as a helper spins the starter. There should be a snapping blue spark. A quiet yellow spark will not do. If you have a snapping blue spark, you should not have an ignition problem.

Let us know what you find...