Wiring For Idiots

[coupe72001]

Completed my engine and gearbox swap on the weekend... other than one or two wiring issues. The new engine is running an electric fuel pump (not mechanical) - so I have to cut into the wiring somewhere to power it. Does anyone have any suggestions for something really easy to find in the C210 engine bay that that I could connect it to - I guess something that is an accessory, rather than getting constant power... I basically suck at deciphering wiring diagrams and electrical stuff in general.

I also noticed that my old distributor had one wire connecting it to the spagetti, but the new one has two wires... I might just recycle the old distributor for simplicity's sake.

Anyway... can't wait to test drive.

Cheers

Drew

[coupe72001]

...actually, if anyone has a good photo of their twin carb L series engine bay, that would be a great help... see if I havent made a mess out of the rest of it!

[aarc240]

Have a look alongside the right frame rail just behind the engine mount.

With any luck you will have 2 wires coming out of the harness, one earth and the other powered with ignition. C110's all have it and hopefully the C210 continued it!

What did you swap in there that has two wires on the distributor?

Edited October 3, 2006 by aarc240

[66 skyline gt]

mate ya best bet is to try and get a relay off a gas system... by law when you turn you ignition on, the pump should run for two seconds then switch off.... once you have cranked it over then the pump should run....

pm for me for mo info if need be

[coupe72001]

Thanks for the replies, I will give it a bash tonight.

The distributors on my car and the rally car are actually a slightly different design (maybe one is the 260Z distributor??? - the rally engine is an E88). I am thinking of using the C210 distributor for now, as I can simply reconnect it to the existing wiring. Later I will connect the electronic ignition kit that is gathering dust in my garage anyway...

[coupe72001]

Right! Turns out the distibutor on the engine with the funky wiring is an electronic ignition. Rather than dealing with it, I put my points distributor back on.

I wired up the fuel pump as instructed (thanks to Art and dodgy lightbulb with 2 wires test light).

We now have spark and fuel, and she kicks over... but doesn't start.

I get the sinking feeling that the electronic ignition was on there for a very good reason. The points distributor may not provide enough spark for the twin carb set up.

So tracing the 2 wires coming from the electronic distributor on the rally car, the red one goes to the positive on the coil, whereas the black one goes into the spagetti... Anyone know where it is supposed to end up?

Also... is there something else I may have messed up doing the engine swap? As far as I can see I reconnected everything the way it was previously (there are of course minor differences with the vacumn hoses going from single carb to twin carb).

[V8skylineMAN]

Put the electronic distributor back in, the two wire are in a "T" shape, the wire at the top of the "T" goes to the negative side of your distributor, the other one goes to the positive side, simple as that.

by"kicking over" do you mean it fires but wont run, or do you mean it is winding over but wont fire?

[aarc240]

Don't mix up the mounts and distributors or you will tear your hair out on why things don't line up!

Unlikely that the original dissy and coil can't fire it so look for gross errors in timing.

As Jason says, use the electronic dissy if you can.

The only issue I've ever seen with this was ONE car that had developed more resistance in the wiring than originally designed into it so the electronic ignition wasn't getting enough volts to wotk reliably.

The standard points system has a resistance wire inside the harness from just in front of those fuel pump wires right around to the coil positive.

You can strip that out if you're keen or you can put another wire in parallel to it (either means cutting into the harness down by the right engine mount).

Don't go there unless you have to and yell for help if it looks like you might. There are other solutions.

[coupe72001]

Thanks again for the replies - its a huge help.

The engine is winding over at present, but wont fire... I can crank it till the battery goes flat, but it just wont fire. Came close though... rumble rumble RUMBLE rumble... false alarm.

I also suspect a massive timing error - but I cant tune it till it is actually running... Arrgh! (Unless there is a trick I dont know about)

The electronic distributor looks a bit like this one (but less shiney)

http://www.pertronix.com/new_products/igni...ess/ig_pg32.htm

The red and black wires hang togther off the side of the distributor. I traced the red wire to the coil positive, and the black goes into a tangle. Ill look again closely tonight...

Just googled electronic ignition, and it looks like of those 2 wires one is ignition, one is coil +, and there needs to be an earth somewhere in the system.

I actually had a starting problem like this earlier this year, and it turned out to be a shabby .50c connector on a distributor wire causing a weak spark.

Anyway, Ill see how I go tonight.

Thanks again.

[V8skylineMAN]

ill post how to set static timing when i get home from work....i dont have time right now.(see post time)

[rorz]

Hey man i have the same problem as you in my R31 skyline, I did a engine and manual conversion and it has spark and fuel but doesnt start. i doubt my timing is out becuase before i did the engine swap the engine was running sweet so theres no reason for the timing to suddenly go out? unless there is a way?

[aarc240]

Did you swap the ECU from the manual also?

Not sure about the R31 but the VL doesn't seem to like the ECU from an auto unless it also has the trans controller (no idea why!)

Does it try to start while cranking and then quit when the key goes to run?

Have you checked the plug wires for correct firing order? How about for #1 being where it should be?

[rorz]

Did you swap the ECU from the manual also?

Not sure about the R31 but the VL doesn't seem to like the ECU from an auto unless it also has the trans controller (no idea why!)

Does it try to start while cranking and then quit when the key goes to run?

Have you checked the plug wires for correct firing order? How about for #1 being where it should be?

It turns over but just doesnt start. And i used the manual ECU and loom. And i dont know what you mean about the plugs and firing order but when i did the engine converion it was a straight swap i didnt touch any individual parts of the engine e.g. distributer or coil. Any other ideas? also , my old exhaust doesnt bolt up to the extractors... so maybe theres not enough back pressure to start? could that be why?

[coupe72001]

Hey mate,

My problems with timing and the wrong lead to the wrong spark plug came from mixing and matching componentry, an issue that you shouldn't have, given you never disconnected your distributor or leads.

However, I also managed to foul up my carbies jiggling them about so much during the swap. So even with the electrics sorted it STILL wont idle under 3000rpm (breaks down and cries like child)...

So you may be in the same boat as me if your engine was anything other than upright and unshaken at all times... that is if your R31 even has carbies, I dont know much about those modern cars

[coupe72001]

Forgot... and this may be a grossly inaccurate statement, you may have cooked the modulator in your distributor if you wired it up incorrectly. When the moduator is fried it'll crank, but not fire... I think...

[rorz]

Cool thanks mate,

My cars down at the sparkies at the moment as has been for the past week and they dont seem to be making any progress which is why im asking. Anyone know if it could be becuase of back pressure as my exhaust doesnt bolt up to my extractors.

[aarc240]

Lack of exhaust back pressure won't cause the engine to fail to fire.

We've tended to concentrate on the ignition but...

Assuming you get a halfway decent spark, get someone to crank it over while you use a screwdriver as a stethoscope to listen to the injectors. You should hear each of them ticking away evenly as the engine cranks.

Reduce the load on the battery and starter while doing an injector check, pull the plugs and disconnect the low tension leads from the coil. It will spin over a lot faster and you should very quickly be able to smell fuel (no smell would make me suspect problems in the injection and/or fuel supply)/

You have spark, tested how?

Be a bit careful with disconnected leads with the engine cranking over, I've known electronic ignition modules to fail when the HT leads were disconnected (back EMF causing a larger than normal reverse voltage spike and bang)

Use a spare plug with the body grounded against the engine.

You should see a healthy blue flash across the electrode to body and hear the crack.

If the spark is more red than blue, check for poor connections to the coil.

If it is marginal, CAREFULLY test by inserting a straight screwdriver shaft into the plug lead, hold on the far end of the plastic handle and keep the screwdriver shaft no more than 3mm from a good earth (cam cover is good). With someone else cranking the engine, slowly move the shaft away from earth until the spark just stops jumping the gap. Immediately bring the shaft closer to earth to resume spark jump.

You should have got at least 9mm gap before it failed to jump. 12 to 15mm is a healthy electronic ignition on those cars. Anything less than 9mm means it won't fire a cylinder under compression.

Make sure your battery is well charged, R31's and VL's don't like starting if the battery is a bit down.

Swap parts one at a time from the old engine and try starting it with each change. If it doesn't work, go back to the parts you had on there.

Edited October 12, 2006 by aarc240

[rorz]

Thanks for all the help mate i'll have a look at it tomorrow night and get back to you,

Cheers.

[rorz]

Well i got the car back its running all sweet the sparkies sorted it out, i gave them the information you told me so thanks for that. Unfortunately i still have 3 problems:

1. Its running off just extractors (so its INSANELY loud and it backfires/misfires and whatnot)

2. Driveshaft is sliiightly too long. It still drove fine but i dont know what could happen with that

3. The Auto diff means i have a different diff ratio, so it revs quite high at 70kmph in 5th gear?!

Any suggestions would be great, this whole thing is almost finished! i got big plans for this r31

Cheers