[CroCivic91]

So, your 88-91 Fuel Injected Honda Civic won't start? Many people here had similar problems (including me), and I'll try to explain a few troubleshooting tips that might help you get your Civic running again. Even if your Civic is a bit older, or a bit newer - you might find some interesting informations here.

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Some, perhaps unknown, terms I'll be using here:

MPFI - Multi Point Fuel Injection - MPFI engines have 1 injector for each cylinder. Standard Civic engines have 4 cylinders, and so they have 4 injectors. Fuel to the fuel injectors is brought through a fuel rail which is connected to a fuel filter. Each injector has an electrical connector attached to it, which brings signals from ECU telling injectors when to inject gas.

DPFI - Dual Point Fuel Injection - DPFI engines have 2 injectors in the throttle body, one main and one auxiliary. Fuel to them is brought through a line from fuel filter to the throttle body - if injectors are pulled from a throttle body, they do not get gas. Injectors also have an electrical connector attached to them which brings signals from ECU saying when to inject gas.

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One of the first things you want to do when you have problems with your Civic is to check your ECU / ECM (Electronic Control Unit / Electronic Control Module) for error codes. It is a metallic box, placed under the carpet, below the glove box, where a passenger would usually keep his/her feet while driving. Pull the carpet down a bit, and you'll see it. There will be a circle on the metallic sheet, which is just an opening through which a red LED light can blink. When you turn the key to position "II" (when the Check Engine Light, Oil light and Battery light turn on, but you do NOT yet crank the car) the LED will blink once, as if it's saying "Hello there, I'm alive...". That LED will report any error codes it might have stored after the initial hello-blink. Error codes are coded with blinks as follows: number of short blinks = error code, pause = another error code is coming now. For example, if you're getting a "HELLO_BLINK-pause-blink-pause-blink-blink-blink-blink" it means the ECU stored error codes 1 and 4. Once all error codes are "blinked" (displayed), ECU will "reblink" them again. Notice that if you're getting something like this: "HELLO_BLINK-pause-blink-pause-blink..." it means that ECU has an error code 1 stored. If there are no error codes, then the ECU will just blink once and will not blink again.

After you've written down all your error codes, you can search online for an error code list. You can find an error code list on www.4thgenerationcivic.com

Now error codes might give you an idea as to what's going on. One of the very common error code you can get is 16. It means there's something wrong with Fuel Injection System. Now, don't go running right away, trying to replace fuel injectors. If your car is having a hard time starting in a hot weather (after being parked in the sun for an hour or so), or if you shut it down, go to the store, come back and it won't start, AND you check your ECU and see an error code 16 - you most likely have a bad Main Relay. It's such a common thing with Civics. Now don't either go running to the store to buy a new one. All you have to do is take out your old Main Relay, resolder it's joints, and put it back in. I did that to my car (it experienced the same problems I described above) and it's starting every time since I did that. Detailed instructions on how to "DIY (Do It Yourself) Main Relay Fixing" can be found here - http://www.markl.f9.co.uk/howto/elec...main-relay.htm

When you're done with fixing the car, have your negative battery cable disconnected from the car for about 20-30 seconds. It will erase the ECU memory of error codes. It will help you notice any new error codes once you see your car is having troubles again. To make sure error codes are deleted from memory, try checking for error codes when you connect the battery cable again. You should see less error codes then before (hopefully none).

Final note about checking your error codes: Many people will tell you that you should disconnect the negative battery cable for half an hour or more to delete error codes. Official Service Manual states you should only keep it disconnected for 10-15 seconds, so double that if you want to be safe and keep it disconnected for 20-30 seconds. I've tried it and 20 seconds work.

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Problems with starting your car might be caused by not getting a spark, not getting fuel or by your timing being off.

To check if you're getting fuel, the easiest way would be to have someone crank the car while you smell the exhaust. If you can smell gas, it's getting gas. Just a word of caution here - do NOT try smelling the exhaust of a working car. There is carbon monoxide in it, which can, if you breathe in enough of it, kill you. If a car is working, it is getting gas :)

If you're not sure if you smell gas or not, pull out your injectors (if you have a fuel rail and 4 injectors (all 1.6 liter Honda Engines are MPFI, only 1.5 liter DX is DPFI - if you have a DX, try pulling out the whole throttle body which is connected with 4 nuts to the intake manifold)) with the rail still connected to them (and electrical connectors connected to them too), pointing them to somewhere that will not ignite the fuel once they (if they) squirt gas out, and have someone crank the car while you look if gas is squirting out. If the gas is not squirting out, you now know that your car is not starting due to not getting gas to the injectors. It might be caused by clogged fuel filter, clogged fuel lines, non-working fuel pump (make sure you check for Main Relay before you go out to buy a new pump, because Main Relay gives power to the fuel pump - if your Main Relay is not working fine, and you DON'T check it first - you might believe that your fuel pump is not working, and be amazed that your newly bought fuel pump is not working either, all because of a Main Relay) or no gas in the tank (a long shot, but hey... ). If you are getting gas, then connect everything back (injectors into the intake manifold, or throttle body to the intake manifold) and go on checking for spark.

Now for spark - I'll quote labman (member of this forum)... "If it has spark plug wires, pull one off and hold the terminal near a ground while somebody cranks the engine over. If you don't get a spark, start checking the ignition system." So, since we do have spark plug wires, pull one off. Now there are two ways you can check for spark: with a spark plug or without. If you want to do it without a spark plug, do as labman said. I personally like the spark plug method better. Take one spark plug (known working one), plug it into the wire until you can feel it touched the metal inside the wire, hold the wire by it's top (what you used to pull on to pull the wire out of the spark plug hole in the valve cover) and make contact between the top of the spark plug and the chassis (any piece of body under the hood enough away from the fuel filter and fuel lines). Now have someone crank the car while you look for sparking on the spark plug. Do this process with all 4 spark plug wires. If you're getting a spark on each wire, then the only problem might be wrongly set timing. If you're not getting a spark, and ignition coil and igniter unit both test fine (read on for procedures how to check those), then either spark plug wires or distributor cap and rotor must be replaced (wires, cap and rotor are cheap things... you should replace them all if you're not sure when you last replaced them). If ALL fails, it might be possible that your internal sensors inside the distributor went bad. You should replace the whole distributor.

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Checking your spark plug wires:

Service Manual says that you disconnect each spark plug wire off and measure resistance between the 2 ends of the wire. Resistance should be less than 25000 ohms on each wire.

When taking wires off, it's best to do one at a time. If you take all off and forget where each one was connected to, and connect them back in wrong order, you will get sparks on wrong cylinders, and your car surely won't start. So, be safe and take off one wire at a time.

[CroCivic91]

Procedures to check if your Igniter Unit or Ignition Coil is bad.

In order to reach the Igniter Unit, you should remove the Distributor Cap and Leak Cover, which is a plastic thing just under the Rotor (it might help if you remove the rotor as well). Ignition Coil is on top of the distributor (you'll only see it if you remove the Distributor Cap) and the Igniter Unit is a match-box like unit, just under the rotor. You can see it once you take the Leak Cover off. Now you should see 4 wires connected to the igniter: WHT, BLK/YEL, WHT/BLU and BLU.

Now here is how to diagnose problems with the Igniter Unit:
Check for voltage between the BLK/YEL wire and the body ground with the ignition switch on. There should be battery voltage. If there is no voltate, check for an open in the BLK/YEL wire between the igniter unit and the ignition switch.
Next, check for voltage between the WHT/BLU wire and the body ground with the ignition switch on. There should be battery voltage. If there is no voltage, check for: faulty ignition coil or an open in the WHT/BLU wire between the igniter unit and the ignition coil.
Next, check for continuity between the WHT wire and the body ground. There should be continuity. If there is no continuity, check for: and open in the WHT wire between the igniter unit and the ECU or poor ground.
Next, check for continuity between the BLU wire and the body ground. There should be continuity. If there is no continuity, check for: and open in the BLU wire between the igniter unit and the tachometer (or the A/T control unit) or poor ground.
And if all continuity and voltage tests are normal (with a known good 50A fuse), but the engine won't start - replace the igniter unit.

Here is how to diagnose problems with the Ignition Coil:
There is a BLK/YEL and WHT/BLU wires connected to the coil. Call the terminal to which the BLK/YEL is connected terminal A and the other one terminal B. The circular thing on the side of a coil is a secondary winding terminal. Switch ignition to OFF. Remove the screws and disconnect the wires from terminals A and B. Using an ohmmeter, measure resistance between the terminals. Replace the coil if the resistance is not within these specifications: between the A and B terminals - 0.63-0.77 ohms, and between terminal A and secondary winding terminal - 9,760-14,640 ohms.

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Igniter Units from 1.5 and 1.6 Civic engines are interchangeable. I have a working Igniter Unit from a '91 JDM CRX (1.6 DOHC D16A8 130HP MPFI engine) in my '90 USDM Civic (1.5 SOHC D15B2 90HP DPFI engine), so it's for sure. Ignition Coils are interchangeable too... same engine as the above one was a donor for my ignition coil.

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Maintenance tips

Check your oil regularly. Do not allow your engine to get low on oil. Also, buy and install only OEM Honda Oil Filter each time you change your oil.

Have your valve clearance adjusted every 15000 miles, or 1 year, whichever comes first. Unadjusted valve clearance might cause your mileage to drop down, and your car will run worse as a result of lower compression.

Do replace your spark plugs, spark plug wires, distributor cap, distributor rotor, fuel filter and air filter if you do not remember when you last changed them. You won't believe the change once you do replace them.

Have your tires properly inflated. It can do wonders to your mileage.

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Final notes

These are just quick tips for those who think they can perform the work on their car themselves. If you're not confident about doing it - don't do it. It's not hard to do, but if you do not understand what you're doing, you might break something, and I don't want to be held responsible for that.

Search the net, learn about your car... all the knowledge that I have about engines and about cars, I learned on the net. At the time of writing this note, I learned about engines for only 8-9 months. Before 8-9 months I couldn't point at an engine head while the hood was opened, and now I'm not afraid to work on my car myself.

As a final notice, let me just give you a link to my web page, where I documented some work I did on my car - http://public.carnet.hr/~kpuljic/honda/
You can find pictures I took while replacing distributor cap and rotor, if you need to know how the inside of the distributor looks like before you open it.

Enjoy your car and drive safe! :)

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This thread is a work in progress - if someone gives me any valuable information or points at something wrong I did here, I will make sure to fix it.

If you do have something to add to this thread - make sure you send me a private message/email, and I will add your info to the post.

[labman]

Part of CroCivic 's post is specific to Hondas, but much of it applies to any car. The fuel rail trick where he quotes me is straight out on the shop manual for the Grand Am I had.

For any no start on any car, the first question is does it turn over? If so, follow CroCivic 's post as closely as you can, even for other cars and trucks. The codes he lists, and the main relay are specific to Hondas. Turn over, spark, fuel, and it should start unless it has severe timing or mechanical problems.

Many cars, like the Grand Am I had or the Cavalier I have now do not have spark plug wires. A wiring harness from the ECU disappears between the camshaft housings. Inside is a module with the ignition module and 2 coils in a housing. The housing has 4 contacts connected to the spark plugs by little springs. You can open it up and do the same resistance measurements as CroCivic gives. You can even run spark plug wires from the contacts to the spark plug wires and do some of the spark plug wire tests.

If it does not turn over, check the battery. If it doesn't have enough power to light the lights or sound the horn, it doesn't have enough power to start the engine. Check the battery connections. Remove the negative one first, and clean it, leaving it off. Then remove clean, and replace the positive, then replace the negative one. With the negative connected, a short from the body or engine to the positive, can cause damage or injury. Try to start. Try a jump.

Next, clean the connection between the other end of the negative and the body or engine and any connection between them. Then follow the positive cable to the solenoid. It is a fat round thing either on the fender or starter. It has 3 connections, the fat wire from the battery, a smaller wire from the starter switch, and another wire to the starter or a short shunt if directly on the starter. With the negative disconnected, clean those connections. There may be several other wires on the terminal with the wire from the battery. Clean them and careful replace them. Reconnect the negative and try start.

Next, with everything connected, and the key in run, place the tip of a plastic handled screwdriver on the terminal of the small wire of the solenoid. Again, this can cause big shorts, and injury or damage. Touch to other terminal first, and the battery second, and nothing else with the screwdriver. Tilt it until the blade contacts the wire from the battery. If it starts, the problem is in the ignition switch or wiring. If not, place the tip on the terminal to the starter, and again tilt it to contact the battery wire. If the engine then turns over, the solenoid is bad. If the engine still doesn't turn over, the starter is bad.

[kwine]

A few things to add regarding my experience with this problem on a '91 Civic Hatchback:

The symptom was very similar - the car would usually start, but every now and then it would get in this mood where it would refuse, sometimes after it had been running a while (like leaving a store where it was parked for 20 minutes), but sometimes also in the morning. Interesting thing was it almost seemed correlated to the level of fuel in the tank - the lower the level, the more likely the problem, but this may have just been coincidence. The problem was slowly worsening over the period of a year or two until finally the car wouldn't start at all.

Sixteen blinks on the ECU LED. Just un-hook the carpet under the dash on the passenger side and there is the ECU and the LED through a hole in the metal cover. The carpet un-hooks - don't try taking out the hook.

The relay is near the driver-side fuse panel. "Less accessible" is an understatement. To really get at it would require totally dismantling the dashboard. The fuse panel cover comes off easily (see owners manual if it's not obvious). I removed the ash-tray (3 screws - obvious) and one dashboard bolt to the left of the fuse panel which allowed just enough access to the bolt attaching the relay bracket to the frame. Must use a socket wrench - UV jointed socket might have helped as well. The relay bracket bolt was super tight. The metal bent. Getting the connector off is a bit difficult but obvious.

I opened the relay and inspected the solder joints - under magnification actually. There was one suspicious joint but very subtle. I probably should have poked around with the ohmmeter to verify, but I was so sure the relay was the problem that I didn't bother. I re-heated all the connections, adding a little solder to each one. It is important to remove the flux residue - leaving the flux can also contribute to solder joint failure over enough time. The manufacturer didn't remove the flux by the way. Conformal coating is a good idea - if you have some handy.

The fuzzy schematic on the site linked to by CroCivic is probably correct as far as the relay internals are concerned. I did trace out the connections and components and came up with the same thing. I also tested the relay on the bench after the re-soldering and it worked fine.

Put it all back together and the car started right up. Yeah :)

[CroCivic91]

I have added some information to the original post.

- explained "MPFI" and "DPFI"
- added information on how to check for gas
- added information on how to check for spark
- moved ignition coil and igniter unit testing procedure to another post because it was over 10.000 letters long, which is too much for a single post :)
- added procedure for checking your spark plug wires

[CroCivic91]

For anyone wondering what an igniter unit looks like, here are some pics. It is a picture of an open igniter unit. I heavily advise AGAINST opening up your igniter unit if you want it to keep working. Also, you can see a close-up picture of what I believe to be causing this igniter to not working any more. Those 2 wires in the center connect to a squarish metal plate, and you can see burn marks on the left one.

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If you want to know EXACTLY how your Main Relay works, then this is the right place for you - http://www.tegger.com/hondafaq/mainr...ion/index.html

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The first thing you want to do when you try to troubleshoot your car is retrieve it's ECU Error Codes.

PLEASE, ALWAYS read your error codes BEFORE you ask a question here. At least on 88-91 Civics. Reading codes on those is VERY easy and requires no special tools.

[CroCivic91]

If you want to know EXACTLY how your Main Relay works, then this is the right place for you - http://www.tegger.com/hondafaq/mainr...ion/index.html

[CroCivic91]

The first thing you want to do when you try to troubleshoot your car is retrieve it's ECU Error Codes.

PLEASE, ALWAYS read your error codes BEFORE you ask a question here. At least on 88-91 Civics. Reading codes on those is VERY easy and requires no special tools.