VX diagnosis help - Solved! - Fuel Economy, Hypermiling, EcoModding News and Forum

1carnut · 08-09-2012, 08:44 PM

I have a 94 VX that died on me on the way home. I'm thinking electrical and might suspect the ignition switch but I thought that I would reach out here since there is so much knowledge. Here is what it did. Started fine leaving work and I had driven about 3 miles when I felt what seemed like a miss but when I looked I noticed that the tach was at 0. I turned onto a side street and when I pushed in the clutch, it was indeed not running. I put it back in gear and tried to kick start it. The tach came back up for a couple seconds and I thought it would be okay but then back down again and I had to coast it to a stop and it wouldn't start. All dash lights look normal and it cranks over just fine. Has gas and I believe it's getting gas. The thing that makes me suspect the ignition switch is that a couple of times when turning it back towards the off position between attempts, the motor kind of tried to start and it even fired for a couple seconds one time. I don't know how the ignition switch comes apart exactly. I have the cover off but not sure what's next. I thought of checking grounds but if it cranks, can they be bad? Fuses? If anyone can give me a step by step of things to check or if you have had a similar issue, I would really appreciate any insights.

scivicblu83 · 08-10-2012, 07:49 AM

check the ignition module inside the distributor, these go out pretty often, the can be checked at autozone with their testing equipment and aligator clips. looks like this http://www.am-autoparts.com/Honda/Ci...FQQ4nAodXnoAKw

California98Civic · 08-10-2012, 08:05 AM

Suspect the ignition coil too. I had a similar problem last fall in my 98 DX. Turned out that the ignition coil failed once it got truly hot from some run time. My coil tested within normal range once I warmed the car up to the point where the cooling fan came on. But the car failed again when driving. I noticed both failures were after roughly similar time/miles from a cold start. So to simulate the fail situation (took forever to come to this procedure) I stayed home and simulated the 15 mins driving time at my usual roughly 1800-2200 RPMs by simply holding the throttle in my driveway. Failed again, and this time the coil failed the test too. The igniter was bad as well (aka the "ignition control module"). I got a replacement distributor at Autozone with a lifetime warranty. No trouble now for about 8 or 9 months.

Honda-tech.com has some great people on it who can help (also has packs of roving kids). "Test, don't guess," was the best advice I got. Patient testing saved me from throwing a (used) $100 ECU and a $35 MAP sensor at the problem. Both of those parts turned out to be unnecessary, but the 96-98 Honda Service Manual suggested they could be the problem so I checked it out.

1carnut · 08-10-2012, 10:56 AM

So I pulled a spark plug and set it against the valve cover so that the side was grounded against the cover. Had someone turn the engine. A single spark when the key was turned towards off but no spark when the engine was turning over. So pull the ignition coil and have it tested?

scivicblu83 · 08-10-2012, 11:11 AM

you will have to test the coil's resistance with a multi meter, i dont think auto parts places do that. the ignitor, or ignition module can be tested at some parts places. the coil will be cheaper to replace at about 30 dollars the ignitor is about 100 dollars

scivicblu83 · 08-10-2012, 11:15 AM

1. With the ignition switch OFF, remove the distributor cap.

2.remove the two screws to disconnect the BLK/YEL and the WHT/BLU wires from terminals A (+) and B (-) respectively.

3.Using an ohmmeter, measure resistance between the terminals. Replace the coil if the resistance is not within specifications.
Primary Winding Resistance (between the A and B terminals): 0.6 - 0.8 Ohms.
Secondary Winding Resistance (between the A and coil wire terminals): 12.8 - 19.2 kOhms
NOTE: Resistance will vary with the coil temperature; specifications are at 20°C (68 °F) .

scivicblu83 · 08-10-2012, 11:31 AM

how to test the ignition control module or ICM.

1.Remove the distributor cap, the distributor rotor, and the inner cover.
Ignition Control Module

2.Disconnect the BLK/YEL, WHT/BLU, YEL/GRN, and BLU wires from the ICM.

3.Turn the ignition switch ON. Check for voltage between the BLK/YEL wire and chassis ground. There should be battery voltage.
If there is no battery voltage, check the BLK/YEL wire between the Ignition Switch and the ICM.
If there is battery voltage, go to step 4.

4.Turn the ignition switch ON. Check for voltage between the WHT/BLU wire and chassis ground. There should be battery voltage.
If there is no battery voltage, check the Ignition coil and WHT/BLU wire between the ignition coil and the ICM.
If there is battery voltage, go to step 5.

5.Check the YEL/GRN wire between the Engine Control Module (ECM) and the ICM.

6.Check the BLU wire between the tachometer and the ICM.

7.If all tests are normal, replace the ICM.

1carnut · 08-10-2012, 12:52 PM

I did the first test and appear to have (my ohmmeter is really cheap) the correct .6 - .8 ohms on the connectors in the first test. Does that mean that the ICM is good and the ignition coil is bad?

slownugly · 08-10-2012, 01:03 PM

ive done 5 of these in the past 6 months (customers and mine) last one was my teal vx did the same thing with the misfire and tachometer. ignition switchs go bad. NOT THE TUMBLER!! the plastic switch and wiring harness that goes down into the fuse block. way to tell is once the vehicle starts dont let the key go back into the on position hold it forward a little bit and if it stays running in that one position then its the switch. the plasitc switch must wear out and im seeing it pretty frequently. they are pretty easy to do ill post a link of the ebay one i used which worked fine. my aftermarket supplier wants to sell everyting together as one unit (switch/wiring/ignition lock cylinder/new keys) for hundreds of dollars but i found a better way out.

scivicblu83 · 08-10-2012, 01:04 PM

did you check the Secondary Winding Resistance (between the A and coil wire terminals): 12.8 - 19.2? if thats good too then the ignition module needs to be tested, its expensive to replace if yours wasn't bad to begin with. if you do replace the ICM you will need a good quality ( at least craftsman) screw driver because the screws that hold the rotor and the ICM will strip easily, they tend to be hard to break loose (iv'e had to dremel them into slotted screws before) .

make sure you are getting fuel by smelling the tail pipe for a gasoline smell not just the exhaust smell that always there. the civics have have a main relay in the drivers kick panel just forward of the door that goes bad, which you have to repetedly kick while cranking if it is bad. if it is bad, when you try to start the engine it will just crank and not fire.