Just finished my project (97 ek ) and had it tuned on the dyno, it was dialed in and running beautifully....for the first three days, then it wouldn't start. I checked the spark by pulling a wire while a buddy turned it over and could barely notice the faintest of spark...

Here are a list of some key items that might help you to know whats going on:

Tuned on Neptune
ID 1000 cc injectors
Optima Yellow Top batt.
Msd obd2 dizzy with external blaster 3 coil.
Brand new plugs (re checked to make sure)
battery ground, and starter ground are solid
power voltage checked at bat. and at starter and both are great

Ok, now before I get the usual bs about how I should replace the dizzy and replace the coil, let me tell you the tests I've done. Oh and p.s I've got fuel/fuel pressure, and timing is dead on,

I have taken my MSD dizzy and coil off my car and tested it on my DD and it fires right up. I have also taken my stock DD dizzy and hooked it up to my car and it STILL barely sparks for ****. I then tested the MSD dizzy again on both rides checking to see if there was a difference in spark and there was a HUGE difference. On my daily driver the MSD sparks up like a ******, but on my turbo civic....weak as dog crap. I'm totally confused. It rules out the coil being bad on my MSD dizzy, which is what I was convinced it was until I did my tests. I am wondering if the ECU has anything to do with the AMOUNT of spark sent to my dizzy? Where does the dizzy get power from? The only thing I can think of now is that the problem lies between my power source and the dizzy.....almost like the dizzy isn't getting enough volts to send a strong spark. But the problem isn't in the actual distributor itself because it sparks so hard on my other car.

This needs to go away asap so I can get this bitch out on the road.

thanks in advance for the wisdom.

 

Bump for genius

 

up for some serious sunday techs

 

did you put on a new head? if so the dizzy could not be the matching one. Also try testing the spark plug wires as well unless you got new spark plug wires as well. and if you got new wires you need to make sure they are the right ones for the car. if your running v-tec with none v-tec spark plug wires there is your problem there. same with the other way around. if the dizzy is working fine the next problem is the wires most likely. had the same problem with my 91 civic and so i threw some new NGKs on there and it fires great.

 

Not to be ungrateful but, really? DOHC VTEC dizzy's are the same. And yes I have new spark plug wires and plugs. You obviously did not read my post.

 

Bump for a non-trial user answer.

 

I would test the 12V+ input to the distributor, [stock lead should be black/yellow], it should be 12.5V.
Check ground continuity of the distributor to the head, ground continuity of the head to chassis.

Also check the main grounds, [batt. to chassis and chassis to engine] I know you said they are solid, but remove them, clean both contact surfaces, and reconnect, do the same with the VC ground

 

Whenever i have electrical problems like this on a car/friends car the first step is always CLEAN all the grounds to bare metal (piece of sandpaper works perfect).

then condition of the entire ignition system (which you said was fine)

then if there is still a weak spark it is time to go through all the wiring and try to find a loose/bad connection.

 

Had the same problem before this caused it. Poor current flow to the ignition coil.

 

Good stuff, thanks guys..... I'll check the lead distributor power input.

If it is not getting 12.5v what is responsible? ECU? or?

 

The ign. switch supplies 12V+ to the distributor assembly through a number of connections and most likely a fuse, [what is MM&Y of car?] anyone of the connections can be bad or, if there is a fuse, the fuse itself may be defective or the fuse to fuse socket connection may be bad.

Start by testing voltage at the distributor, don't forget to test during cranking to start.

If voltage is low, test at ign. switch, [again, when cranking to start] and then move down the line until you find the bad connection. 94

 

It's an EK, 97 civic. I checked all the fuses and none are blown. I checked power to distributor blk/ylw wire with the ignition switch on to II....continuity is good.

What's the best way to test the voltage of distributor? Leave cap on, take off? or just spike the wires at the engine harness plug?

 

Your checking for power not continuity, what is the voltage on the black/yellow, both when ign. switch is on, [position II] and when cranking, [position III]?


You can just unplug the distributor and test the pin of the black/yellow lead, I am no fan of "spiking" wires, unless you have liquid electrical tape to reseal the hole you punch in the insulation, again test for voltage both in run and start. 94

 

Okay, heres the update on the voltage tests:

Battery- 12.53V

Alternator- 12.53V

Starter- 12.53V

Dizzy BLK/YLW WIRE- 11.83V @ pos II and 12.05V @ pos. III

Ignition (at steering wheel)- Same as Distributor.

 

12.05V at distributor when cranking, [.5V from 12.53V at batt.] is normal, why it is only 11.83V in the run position would make me think ign. switch is bad.

What is voltage at the input to the ign. switch?

However the above does no explain a weak spark, [at plug wire] when cranking to start.

What/where are you jumping the spark to? 94

 

I think the .5V disparity in the ign and under hood fuse (42) is coming from the kill switch located in the rear and the smaller wire (8 gauge) that the tuner installed. However, it should still have enough juice to fire.

Is the input to the ign. a Wht wire? I usually check spark by simply pulling a wire and holding near the inside of the valve cover.

 

Yes, white lead is ign. switch input, it should be at 12.53V but no less then 12.05V.

As I said, a drop of .5V at coil when cranking is normal, and yes, it would not result in a weak spark.

Pick up one of these, [or one like it].... http://www.autozone.com/autozone/acc...uestid=1712227 and ground it to the head or engin block, [not the valve cover] you can jump the ground with the lead or ground a plug to the head/block also.

Have you checked the engine and harness grounds? 94

 

ign. input is 12.53V

used a spare plug and tested spark again on each of the wires, grounded plug to the head....spark is borderline, seems like it should have enough to start....?? This is getting so ridiculous.

 

if your using a OBD 2a to 1 conversion harness check the wires that go to pins A25 And A26 in the ecu. just went thru a similar problem weekend before last at montgomery IFO. Those are the ground signals to the dizzy. One of the wires A26 had pulled out of the conversion harness on the end that the eng harness plugs into and car was missing real bad, swapped out the dizzy then it wouldn't start. found bad wire on A26, fixed , put original dizzy back in, All good. Good luck! Electrical problems are the worst to track down.

 

Have you checked your pcm ground for good clean contact points? G101 is on the t-stat housing, the little wire that doesn't look like much. It's a horrible place for a ground wire and on earlier models cause problems from time to time. I usually try to find a spot on the engine block to bolt them.

 

Okay gang, thought I'd return and report. Problem has been identified and solved. After running voltage tests on everything imaginable, the culprit ended up being the ECU. Apparently a couple resistors took a ****. Replaced it, had a new chip burnt and vuala.

thanks for helping me trouble shoot it and narrow the search.

 

great you got sorted!