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No spark at the coil

I am coming to what I though was the end of an engine swap, and I can't get a spark from my coil. I tested the coil (by holding the center spark wire 3/8" near the fan housing as suggested by the Haynes manual) and saw no spark jumping towards the fan housing. I also measured the voltage at terminal 15 on the coil versus the hot battery lead (while cranking) and saw 9-10 volts (jumping around). I believe I have all three wires attached in the correct locations (I labeled them). I also swapped the coil with a spare I have (from the old engine) and saw the same thing. Does anyone have any suggestions? The car turns over (without sparking) well, and this may be the thing keeping me from enjoying my 914 on the road. By the way, it is a 1972 914-4 1.7L chassis with a 1971 914-4 1.7L engine.

While we're on the subject, I am working on this car with no assistant, and I am getting real tired of contorting to turn the engine over with the key while observing something in the engine compartment. Does anyone have a suggestion as to setting up a "remote" (wire connection) starter switch to crank the car while I am out of the cab and near the engine? Nothing too complicated, I hope, as I am straining my intellect trying to figure out how to get the damn car STARTED at all.

Thanks for your advice, and thanks Pelican guys for your help thus far.
Old 10-21-1998, 09:27 PM
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No spark is bad.

Happily, you don't need to crank the engine over to check for a spark. All you have to do is leave the ignition on.

First, though, open up the distributor and turn the motor to where the points are closed. You can do this by pushing the car back and forth in gear. Then you set the parking brake and turn the ignition on.

Unplug the tach wire from the coil. That's the smaller of the two black wires (it actually has a purple stripe that's hard to see). It should hook up to the same coil terminal as the green wire from the points.

Tape the center coil wire about 1/4" from a known ground, like the fan shroud. Don't hold it with your hand or you'll get one HELL of a shock. (BTDT.)

Now, use a small screwdriver to pull the points open and then let the spring snap them closed again. You should see a spark from the center coil wire to ground during one of those two transitions--forget which one.

If you don't get a spark, there are several things to check out. First, make sure that you have +12V on the coil terminal that the fat black wire hooks on to. (The opposite terminal from the green points wire.)

Then pull the green wire off the coil. Make sure it shorts to ground when the points are closed, and has no connection when the points are open. If one of these two test fails, then something is wrong with your points and/or condensor. We can go into that later if that is the case.

Final test for the coil: Hook up a length of scrap wire onto the terminal that the green points wire came off of. Use some rubber-handled pliers to touch it to a ground and then pull it away. You should get a spark on that center coil wire on one of those transitions. If you don't, and you've got +12V to the other coil terminal, then the coil is bad.

Good luck with the testing!

--DD

PS--The coil is "directional", it does matter which side you hook the wires to. Haynes has little numbers on the wiring diagrams that correspond with the numbers "printed" on the coil cap. A short reference: The thicker black wire goes on the "+" terminal; the thinner black/purple wire and the green points wire go on the "-" terminal; and the THICK coil wire goes onto the center terminal.

[This message has been edited by Dave_Darling.]
Old 10-22-1998, 08:45 AM
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You can buy a remote starter at Pep Boys or Autozone take the alligator clips and attach to starter, hold in hand and squeeze trigger to turn engine over, have the ignition key in 'On" position
Old 10-22-1998, 01:08 PM
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I still have no spark--does anyone have any suggestions on how I am screwing this up?

I went through Dave's instructions (very clear--thank you): my coil works fine: I get a whitish-blue spark when I tape the center coil wire (that normally goes from the coil into the distributor) onto the fan-casing (I rotated the distributor to OPEN by turning the rear tire with the car in 5th, and I flicked the point open and then closed with a small screw driver). My distibutor seems to work: I get a reading of over 12 volts at the distributor spark-plug wire terminal (where those 4 thick spark-plug wires plug into) when I open and then close the points AND when I rotate the distributor with the tire in 5th. BUT, when I instead hook the spark plug to this terminal via the spark-plug wire, I get no spark. I tried several different spark plugs--old ones I know worked a few months ago (albeit not well) as well as new ones. Do I need to ground the spark plug body to get a spark (I didn't think so from the schematic)--I am not grounding them when I am testing them out of the engine body. If it is not a grounding problem, does anyone have any new suggestions? I have a few other problems (like I am not seeing any fuel getting through the fuel lines) that I thought I should wait to complete until I know I get a good spark.

Also, when I had accidentally switched the wires on the coil, I saw a thin white smoke coming from inside my distibutor (just for a second, before I cut the power). Did I damage my condenser, and is this why I get no spark? All the tests described above worked after the smoke occured, and I still get over 12v at the spark-plug wire terminals. I have an extra condenser if I need it.

Thanks for your help and any suggestions.
Old 10-26-1998, 08:45 AM
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The spark plugs ground through their threads into the head. So if you didn't have the plug grounded, you wouldn't see a spark.

If you're only seeing +12V at the plug end of the plug wires, something is wrong. I believe that the spark impulse is supposed to be on the order of 10,000V or more. You can rotate the engine such that the rotor is pointing to the #1 plug's terminal, then put the dizzy back together. Tape the plug end of the #1 wire so that the conductor is 1/4" from ground. Unplug the points wire and tach wire from the coil. Then turn on the ignition and use some scrap wire to make and break a ground connection to that electrode of the coil. You should see a spark. Ditto after you plug in the plug and tape the plug threads to a ground.

Smoke from inside the distributor is not a good sign. Something got overheated, obviously. The question is, how seriously? The points ground through the breaker plate, which is the thing that the points are screwed into. The breaker plate has a thin braided ground wire that attatches to the body of the distributor. That ground path must be good, and should have a low resistance.

Try the check of the plug wire. Then try with the spark plug attatched, and the end grounded. If that works, then you'll need to hook up everything (but the tach) and get someone to crank the motor while you look for a spark at the plug. Then hook up the tach and look. If that all works, put it together and start chasing your fuel problem.

If you don't get a spark at one of those steps, then trace down where the juice is coming from and see what element you changed in the test that didn't show a spark. That's probably the element that's wrong.

--DD
Old 10-26-1998, 11:43 AM
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If you have spark at the end of the coil wire where it would plug into the distrib, but none at the plugs, the problem is in the cap, rotor or wires. Make sure the cap is not cracked and the little contact in the center is there as are the ones for the individual plugs. Our rotors have a resistor built in and it is under an epoxy that is on the arm that goes from the center contact to the end of the rotor, make sure it is not fried as it happened on our Turbo and it ran terrible, but it also has a lot higher voltage coil. Finally check the wires for resistance as per the Haynes manual (I think). I have seen people put "racing" plug wires on and they not work as their resistance was off.
Old 10-26-1998, 01:19 PM
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Been there, done that.

When I got my fuel injection to replace the carb I saw that the ignition wire harness (also goes to the back up switch and oil press sender) was fried at some point in its life. Sooo I being smarter than the Porsche factory decided to rebuild it, faster, stroger, better. I took the 12 pin plug apart, unsoldered the burnt 18 ga wires, and replaced them with new 16 ga wire of the approprate colors. Didn't bother to check the wiring just put it back the way I took it apart. Well the car didn't start, and I smelled smoke. It was that electrical fire smell, and then I saw the smoke from under the cap. I had put +12 to the neg side of the coil because (either the PO had switched them or I screwed up) the blk/pur wire was on the wrong pin. The points wire had NO insulation left and was dark brown and twisted. So I replaced the new points and condensor with a second set of new points and cond. After I went through each wire with a wiring diagram of the relay board the car started up.

So, yes, I would put a new condensor on, while you're at it new points too. Like the others said the body of the plug must be grounded. Also go through the Haynes manual to check the static timiming of the dizzy. Something like the points "just" open as the engine reaches TDC on #1. Or there is something about .004" of gap between the points at a certain crank angle. Sorry I don't have my Haynes with me.

For the fuel problem, 1. Is the pump running? It should go on for a few seconds then go off until the starter cranks. 2. If not check the rear fuse in the relay board and the second and third relays. 3. Check the routing of the 3 fuel lines that go into your pump, I'll look at mine if you can't find it anywhere. 4. Are you saying that fuel dosen't come out the injectors, or it doesn't even make it to the test port?
Old 10-26-1998, 05:00 PM
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Well, I got a spark finally. It was my sheer stupidity, not having grounded the spark-plug body. All and all, it seems ok--all the sparks produce a strong bluish-white spark when I rotate the tire to the proper location. I actually have a spare distributor and condenser so I could, if needed, replace both (or pieces of either). But I did a bit of distributor investigation last night and found that there is nothing "obvious" (to an extreme novice) wrong: the braided wire grounding the plate was intact and mostly insulated (looks a bit shabby, but it grounds the plate ok); the points don't have a bulb on the side, and don't seem pitted. I likely will replace the points, the braided grounding wire AND the condenser when I do my tune-up, but, since I don't want to spend TOO much money quite yet (then why did I buy a non-working 914?), I want to get the car working so then I can replace and upgrade items knowing the car actually works (and what specifically I have screwed up replacing said items). I'll do the timing when I do the replacement/upgrades.

So now its off to figure out why no fuel is getting to the pump. I hotwired the fuel pump to the battery and it seems to work fine (it at least whirls), but no fuel comes out. So I assume that, since I recently put gas in the tank (and the gas gauge works) and I don't see a large gas puddle on my garage floor, I have a clogged fuel line leading from the tank to the pump. I have a sneaking suspicion I will need to pull the tank and put on new fuel lines (good thing there is a Pelican Technical Article on this procedure!) as they might be clogged up. Hopefully I'll give this a try tonight (work, car, work, car, work, car...). As I didn't even know there was a test port (the Haynes manual is a little vague), I will have to hunt for this to see if, indeed, fuel is coming out of the test port. The pump MAY be on briefly when the car is turned over, but I can't stretch that far. (I can't remember where, but I do recall something about a vice grips and cable serving as a "remote" starter). So I'll give this a try tonight, and I will probably have a series of questions tomorrow.

Incidentally, are the fuses labeled anywhere? (the only fusebox I know of is under the dash--are there other fuses hidden throughout the car?) And, if the fuse is good, it should have zero resistance across it, right? (I tested them all this way).

Again, I am grateful for the help.
Old 10-27-1998, 03:18 PM
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So I checked my fuel lines last night and found that I AM getting plenty of fuel to the fuel pump--the lines were not clogged as I feared (although I still don't know where the test port(s) is/are, so I just pulled one of the line and let gas run out before I quickly jammed it back on). And I can hotwire the pump directly to the battery to get fuel to come out (into the lines running in the engine compartment). But, when I turn the car over, I can't hear the pump start at all. Nor does the positive fuel-pump lead ever gain any voltage (on my voltmeter) when I turn the car over (with respect to the negative fuel pump lead OR an engine ground). I think I have good grounds to the engine, and I didn't see any voltage leak occurring. So my guess was the fuel pump relay is bad. I happened to have a few extra lying around, so I opened one up (so I could manually trip the relay) are tried it out--no fuel pump whirl, nothing. I tried it in replacement of the other relays, and I could hear their functions work.

So, is my guess--that the wires running from the relay to the fuel pump are shot and need to be replaced--correct? (I didn't have time to check this with the voltmeter--maybe tonight, if I'm lucky). Could there be another reason for this to occur? I have a profound fear that my control unit might be bad (no reason for this--just a fear, as I couldn't likely fix it myself, and I would need to replace it outright). And are there additional fuses hiding somewhere I need to check (besides on the relay panel)?

One other question: This is a '71 914-4 1.7 engine I have put into a '72 914-4 1.7 body. But I noticed that there are a LOT more exhaust hoses and connections on the '72 than on the '71. Is this, in part, what is fouling me up? I didn't think there would be a real difference between the two.

Old 10-28-1998, 06:51 AM
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The test port is a small plug (bolt) on the driver side fuel rail, the fuel rail is the metal part of the fuel line that goes to the injectors. If the pump is still in the engine compartment (the factory location on 70-74 914's) and you have to rewire it and put in new fuel line anyway, it may be worthwhile to move the pump to the front trunk. This modification stops "vapor lock" the symtom of which is that the car will not restart when hot in the summer. So if this is going to be a daily driver and it needs to restart then move the pump. I live in Miami and got away with having the pump in back but I had to be careful not to leave the car for more than 5 minutes before restarting it. The test port I think is a 6mm (small) bolt, you can take it out and hook up a pressure gauge to it using a small piece of fuel line.

If the pump is already up front I would definately suspect the PO's wiring to the pump. Next look at the relay board, test for continuity between pins, the Haynes (and the Pelican parts Page I think) has a decent diagram of the circut paths in the board. You say that you checked the fuel pump relay, but also check the one next to it. That one controls power to the brain, and the brain controls the pump. Which brings me to the pump circut, the pump goes on when the key is turned to ingition, but not start, for about 5 seconds. Then the brain turns the pump on during start and keeps it on as long as the engine is running. Check that the fuses (two fuses, one is 15 amps for the heater aux fan, the other is 30 amp for teh pump) are not blown, and also remove them polish the ends a the holders with emory cloth. At the very least "spin" the fuses in the holder. Next unplug the rectangular 12 and 14 pin connectors, look for any corrosion, then plug them back in. The back of the connectors pop off, but be careful. If the pins come out of the connector make damn sure to put them back in the right location (I learned the hard way). With the connector still pluged in, but the back plate off, test the Blk/Red wire for continuity from the pump the the connector. The connector that has the blk/red wire is the one closest to the driver seat.

Next make sure the 4 white wires coming from the brain are O.K. and that the white 4 pin plug that goes into the relay board is O.K.
Old 10-28-1998, 10:10 AM
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I don't know if it has any relevence to your problem, but one day when I tried to start my 914, it would turn over, but not start. I didn't initially hear the fuel pump.

I checked the fuse on the relay board and it was good. I have an old round relay with the top broken off, so I replaced the fuel pump relay with it and manually pushed down on the relay, the fuel pump worked. It turned out I had no power to the "brain" circuit because a wire going to the positive battery terminal (grey with a red strip I think) had corroded. Once I replaced the connector, everything worked.
Old 10-28-1998, 10:25 AM
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OK, you are now troubleshooting your fuel pump control circuit. One of the best articles that I know of on this subject lives in the Tech Refs section of the 914 Fan Page (formerly Tim's Fan Page). Click here: www.914fan.net .

The title of the article is slightly misleading; I think it's called "The 914 Fuel System". But it's really about the fuel PUMP control system.

--DD
Old 10-28-1998, 12:29 PM
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Ok, after a series of mishaps, I have the engine actually working (thanks to all who offered advice). For those of you interested, the problem turned out to be a lose connection in the relay board.

My newest problem: when the engine warms up, the idle becomes erratic--surging from almost zero to 3500 rpm and back. I was told this may be a vacuum leak problem, which, if true, is because I have NO idea how to hook the hoses back together (yes, Wayne, you warned me). And the pictures/descriptions in the Haynes manual don't really help much. (again, I have a 914-4 1.7L 1971) JP Noonan goes through the hose order in the "Decel Valve and air plenum styles" question, but is this for all 1.7s? The reason I ask is I have a parts engine, 914-4 1.7L 1972, and the hose setup is entirely different. Most of the problem is that I really don't understand what all the hoses do. Any recommendations as to where I can go for a description of the hoses, their purpose, and how to hook them up properly?

Second question: Could my high idle after warmup be something else? What else should I check? And, if it is the hoses leaking, should I just go ahead and put hose clamps everywhere?

Third question: Given my inexperience with cars, I think I should have a mechanic do my brakes properly. Any idea how much this should cost? My front rotors look covered in a sheet of rust.

Fourth question: I have the acceleration butterfly valve working ok, but I have no idea where the spring should go to and from. I now have it attached to the car body towards the center trunk. Can someone tell me where this is supposed to go? Again, Haynes pictures are of little use to me.

Thanks, guys.
Old 11-02-1998, 09:44 PM
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For hoses, the closest thing available right now is my 2.0 hose diagram. Check on The 914 Fan Page, www.914fan.net , under the Tech Refs section. (Hey, there's now a 75 1.8 diagram too!!) Both the 2.0 and 1.7 use D-jet FI, so they are similar. However, there are some differences. Probably some of the hose sizes are different, and some of the components are in different places.

Remember that the parts, even if they are in somewhat different locations, all do the same things bewteen the two systems, and so must be hooked up to the same type of vaccuum.

There are three "types" of air that the vaccuum hose system "sees". One is high-pressure air, air that comes from anywhere before the throttle valve. The second is low-pressure air, AKA manifold vaccuum. This comes from pretty much anywhere after the throttle valve. The third type comes from very very close to the throttle valve, and is used to actuate vaccuum advance and retard.

With that to help you interpret the 2.0 diagram, you may be able to figure out where all the hoses go on your car.

The best solution is new hoses, not hose clamps. Oh, and vaccuum leaks can come from other sources than just the hoses--the decel valve or aux air valve could be staying open, the BIG hoses from the manifold/plenum to the intake pipes could be leaking, the seal from the intake pipes to the heads could be leaking, or the fuel injector seals could be leaking. The latter is fairly likely and is cheap to fix. Any VW shop that deals with FI'd VWs will have injector seals.

Finally, the "idle goes from 0-3500-0-3500" is a classic case of a "lean hunt". This can be caused by vaccuum leaks, so fixing the leaks may cure it--or at least lessen it. Also try tweaking the knob on the ECU. CW should make the idle mixture richer, CCW should make it leaner. Try CW first.

Good luck!

--DD
Old 11-03-1998, 08:50 AM
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