Delorean Desnt' Start

[Ryo Seadas]

Hi everyone! I'm going crazy trying to start my friend's Delorean. I should point out that it's a car that has always worked well and has undergone a lot of maintenance, so it's not an abandoned vehicle. It sat idle for a couple of years, only being started a few times, perhaps only to drive it up ramps. At the beginning of December, it was started, driven up ramps, and never started again. At this point, I took the car and did a ton of research (thanks in part to your expertise) and ran tons of tests. I know that fuel is reaching the injectors because I've tested them, and I know there are sparks because I've tested them, both with and without spark plugs. My only concerns are the voltages on the coil and the voltage coming from the starter to bypass the resistors during start-up... I get about 9V output from the yellow and blue wire that goes into the resistors and comes from the starter. I have 12V coming in with the ignition switched on to the right of the resistors, but I have 5V coming out of the resistors (with the ignition switched off) with the coil connected. If I disconnect the coil, the voltage rises to about 8V. During startup, I don't even get 6V on the positive terminal of the coil... so I keep thinking that the bypass coming from the starter isn't working properly... am I wrong? Seeing the sparks on the spark plugs, I think I can bypass the ignition module because it means the signal from the distributor is arriving and being sent to the negative terminal of the coil through the ignition module, which is working.

Is it possible that the spark is there, but it's actually too weak if I have just under 6V at the positive coil? What am I missing? Sorry for the long message, but I wanted to be as clear as possible about what I see and the tests I've done. Thanks to anyone who will take the time to share this adventure of mine.

[Bitsyncmaster]

You will get low voltage to the coil with the stock components. The stock coil is 0.4 ohms and the one 0.5 ohm resistor during cranking will drop you coil voltage under 6 volts. It has worked this way on all cars so I would bet your spark is not the problem. You can always pull a spark plug and look at the spark.

After I had rebuilt my FD, I accidentally must have washed the cylinder walls clear of oil with it miss-adjusted. I never could get it to pop during cranking even with starter fluid. I think it just had no vacuum to pull any fuel. What got it started was injecting some oil into all six spark plug holes. Instantly fired up but wife almost called the fire department will all the smoke.

I'm guessing you have already tried starter fluid with no results.

[Ryo Seadas]

Yes, I tried with the starting fluid, not too much obviously, but the engine didn't even cough... So I understand that in your opinion it could be a vacuum problem.

[DMC-Ron]

Here's a test I would try just to confirm the spark. First, connect the coil directly to a test spark plug grounded to the frame. Using an old spark plug wire, connect the plug directly to the coil. Crank the engine and you should see a good strong rapid spark (you're seeing it spark with every cylinder). Now reconnect the coil to the distributor and connect the test spark plug to any spark plug wire (cylinder 3 or cylinder 6 are the easiest to access). Now observe the spark as you crank the engine (be aware that a working engine could start with a single spark plug disconnected). What you're looking for is a large difference in spark intensity. My car had this issue and would not start. It turned out that over time the high voltage connection from the coil to the center distributor had pulled out at the distributor creating a wider and wider gap. At some point the gap was too wide to allow enough spark to run the engine. Once I found the problem, I had to replace the high voltage wire between the coil and distributor because the original had burned it's tip away. New coil wire, and it started right up.

Ron

[Ryo Seadas]

Thanks for the advice, I need to find a cable that works with these coils or make a real contact because the ones I have won't work. The distributor in the Delorean is really hard to reach, but I was also starting to think there might be problems in that area. I had avoided it because it was almost impossible to reach without removing the intake manifold and because the car was working fine, but at this point I also think I'll have to get there too.

[DMC-Ron]

Well, the test I suggested doesn't require you to have access to the distributor. Rather it will let you know if there is some issue between the coil and the engine spark plug. If the test shows there's not, then you saved yourself from the difficult task of getting to the distributor.
Ron

[r00b]

You can do the cap rotor and wires without removing the intake manifold, it's just much easier if you do.
Make sure the two wires are connected to the resistor and making good contact. while doing my frame off I accidentally broke one of the blade connectors on the the resistor, I used a stainless piece of metal I cut from a band clamp as a temporary fix. When I got everything back together it wouldn't start, It took me days to figure out that metal piece I used was causing the problem.