So I bought a 1992 honda civic DX auto and after a week of buying it, it crapped out on me. It would crank, but would not fire up. Immediately I began troubleshooting. I checked for spark and there was none when I grounded the plugs against the frame several times while my friend cranked it. Next I checked for fuel to the fuel rail, there is fuel flowing when cranked. Also, my valvetrain moves when cranked so my belt is not broken. Everything is connected also.

There was no spark so I replaced it with a new distributor from autozone and it started right up after one crank. The next day I went to start it, and continued like last time; just cranked and would not fire. I exchanged the part from autozone and it still would crank, but not fire up.

I went to eBay and purchased an ECU from a good working Civic DX automatic that was wrecked. The sellers feedback was 100% and assured me the ECU is in working order. Still nothing, just the solid CEL with no clicking from the main relay whatsoever.

Next my determination was the main relay. I had all the diodes soldered and put back in, still nothing. Next I went to Honda and purchased a new main relay with the part numbers matching and it still would not click.

All the grounds are secure and ground properly from the ground wires (the tranny ground, the battery ground and also the engine ground from the valve cover), I get 12v from the battery and I cannot determine what is wrong with my civic. I really need to get this car running and I have spent $500 so far and I am at a total loss and I have no where else to turn. I am an aircraft mechanic for the Navy so I have a good comprehension as to what I am doing. Please help :-/

If you turn your ignition ON, the Check Engine Light, on a properly running Honda, should come on and then go off after 2 seconds. During this time, you should hear the fuel pump run. If the Check Engine Light does not come on and then go off, focus on the main relay, ECM, and ignition switch.

My hypothesis is that your ECM is bad. Run a simple "K-Test":

Disconnect the MAP sensor connector from the MAP sensor. Turn ignition ON and check for 5 volts between the right female reference wire socket (+) and the main ECM ground on the thermostat housing. Really press the black test lead into the ground. If you don't have approximately 5 volts, then your ECM is likely bad. Remember, the ECM is nothing but a giant "power transistor," whose job it is to provide the proper voltage to a host of sensors (transducers) under constantly changing conditions. The confirming test is to turn the ignition switch OFF, disconnect the D harness to the computer, turn the ignition switch ON, and measure the voltage between computer pins D19(+) and D21(-). If there is less than approximately 5 volts, substitute a known good ECM. If you have approximately 5 volts between D19 and D21, repair an open between the ECM and YEL/GRN reference wire going to the MAP sensor.

Most of these "crank but won't start" situations on Civics are main relay, ICM, coil, or ECM related. A few have been caused by bad CYL, CYK, or TDC sensors in the distributor. If your ECM checks out OK, then I would suspect your ICM (igniter), since you just installed a new main relay. A final item to check out is the Manifold Absolute Pressure (MAP) Sensor, which is the "key" sensor on Hondas. It controls timing (similar to the old vacuum advance on distributors) and air/fuel mixture, depending upon manifold pressure changes. Like any transducer, it converts energy from one form to another. Here, it converts throttle body vacuum pressure changes into fluctuating electrical current signals to the ECM. If this sensor does not receive the proper voltage from the ECM, you will experience catastrophic ignition and fuel system failure.

My experience with Hondas has been main relays, ICMs, coils, and ECMs should be replaced proactively after 10 years or 120,000 miles, whichever comes first. Distributor bearings will likely fail around 95,000 miles.

Do I have to find someone to crank the car while I do this or can I just turn the ket to the couple clicks ahead?

Quote:

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Originally Posted by txgreasemonkey

I suspect your ECM is bad. Run this simple test:

Disconnect the MAP sensor connector from the MAP sensor. Turn ignition ON and check for 5 volts between the right female reference wire socket (+) and the main ECM ground on the thermostat housing. Really press the black test lead into the ground. If you don't have approximately 5 volts, then your ECM is bad. Remember, the ECM is nothing but a giant "power transistor," whose job is to provide the proper voltage to a host of sensors (transducers) under constantly changing conditions.

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I also read your other informative post about how your car did not start because of your map sensor. I was thinking it could have been this. Did you buy a new one or was it just the connection?

Crap, stupid me just realized that I never disconnected my battery when I swapped ECU's... do you think I fried the working ECU when I connected it to the harness?

Yes, you have to disconnect the negative battery terminal or you can wreck the ECM.

Only replace the MAP Sensor as a last resort because they usually are very reliable and they cost $225. I ended up buying a new one.

Quote:

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Originally Posted by davin

do i have to find someone to crank the car while i do this or can i just turn the ket to the couple clicks ahead?

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I not sure of your question.

Once you get your Civic running again, be sure to change all of the fluids. I would use Valvoline SynPower Brake Fluid and flush the whole system. Also, I would take a battery squeeze bulb and partially replace some the power steering fluid. I would also drop and clean the transmission pan, change the filter, and replace fluid with either Mobil 1 Multi-Vehicle Synthetic ATF or Amsoil Universal Synthetic ATF. I believe your Civic requires a Dexron II rated fluid. I run Mobil 1 5W-30 synthetic engine oil with a Purolator PureOne filter in my 1993 Civic DX. Finally, I would change the antifreeze with a 50/50 mixture of antifreeze and distilled water. A well-maintained Civic can last 350,000 miles.

So after doing all that, there is absolutely no power coming from d19 and d21 nor is there any power from the map sensor wires to the ground connecting to the tranny. I have swapped out both ECUs that are compatible with my car furthermore.

My assumption is that there is no power going to the ECM, but the strange thing is that there is 12v coming from the battery.

It is not the dizzy because the complete unit was replaced along with a cap and rotor with spark plugs and all.

I am in the barracks with an aircraft electriciansmate and he cannot find anything either :-/

I am not getting power to terminals d19 and d21 nor am I getting power from the map sensor to the ground running from the tranny. However I am getting a full 12v from the battery.

My conclussion is that there is no power running to the ECM :-/

The thing that really stinks about this is, I have only had it about a week before it crapped on me. I bearly gave it any love :-(

The main relay controls power going to the ECM.

http://www.tegger.com/hondafaq/mainr...mainrelay.html

Quote:

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Originally Posted by davin

i am not getting power to terminals d19 and d21 nor am i getting power from the map sensor to the ground running from the tranny. however i am getting a full 12v from the battery.

my conclussion is that there is no power running to the ECM :-/

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When you checked for 5 volts between D19(+) and D21(-), did you have the rest of the harness connected to the ECM and the negative battery terminal connected, the ignition ON, and testing at the "male pins" on the ECM (not on the D connector)?

The solution is going to be something major, not some remote "possibility." The Check Engine Light has to go out for your Civic to start. If it stays on, then there won't be any spark. Likewise, a dead main relay = no spark. I still think the Check Engine Light won't go out because the ECM is bad.

Again, if the CEL will not go out, check the ignition switch, main relay or ECM.

Two additional things to check:

. All under-hood and under-dash fuses. Use your DMM. Pay particular attention to under-hood fuse #31, which is a 7.5A fuse to the ECM. There are four fuses in a row, along the back of the fuse box. This one is located second from the left and, if removed for 10 seconds, will erase any stored DTCs and reset your ECM.

. Main ECM ground. As mentioned above, it is located on the thermostat housing. Remove and examine the 3-wire brass ground, clean with 240 grit abrasive cloth, and apply dielectric grease.

To recap, you replaced the distributor (remanufactured), which had new igniter, coil, and sensors; the main relay (Honda); and the ECM (used)? Or, did you return the distributor to Autozone, since it didn't solve the problem?

Quote:

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Originally Posted by txgreasemonkey

Two additional things to check:

. All under-hood and under-dash fuses. Use your DMM. Pay particular attention to under-hood fuse #31, which is a 7.5A fuse to the ECM. There are four fuses in a row, along the back of the fuse box. This one is located second from the left and, if removed for 10 seconds, will erase any stored DTCs and reset your ECM.

. Main ECM ground. As mentioned above, it is located on the thermostat housing. Remove and examine the 3-wire brass ground, clean with 240 grit abrasive cloth, and apply dielectric grease.

To recap, you replaced the distributor (remanufactured), which had new igniter, coil, and sensors; the main relay (Honda); and the ECM (used)? Or, did you return the distributor to Autozone, since it didn't solve the problem?

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I still have the remanufactured dizzy along with a new cap/ rotor with new plugs, the working ECM from a wrecked civic, a new main relay from OEM Honda and still the CEL light stays on and there are still no clicks from the main relay and everything is installed correctly.

I used the fluke to get a reading from the 3 pin MAP sensor connection D19 (yellow/ green) and D21 (green/ blue) and had no signs of a reading when the ignition was on, but not cranked. I don't feel comfortable cutting the wires from the D-Harness (looking at the ECM, the D-Harness is the mid size connector and D19 & D21 are the two most top right connections all the way at the end).

I really do not think the ECM is bad because I have two P06 computers that both register the same results. I also talked to several other people that I work with in the navy to see if not disconnecting the battery would short the computer, people said it was highly unlikely. Another person, a highly skilled aircraft mechanic that does inspections for quality assurance (these are the most knowledgeable people mind you) and he said he fixed his accords ECM and dizzy without disconnecting the battery and it worked.

Also the engine is TDC (top dead center), meaning that the cams line up with the piston... and since the cam is keyed to the dizzy (distributor), it will fire in the correct order (unless you have your spark plugs all backwards and won't fire right). Furthermore, the valvetrain does move when I crank it from taking off the oil cap and looking for the valvetrain to move when cranked.

I am bringing along an aircraft electriciansmate with me to look at my car. This is way beyond my level of electrical engineering and see if his professionalism hands on will do. Also, I will take off all the grounds and take a wire brush to all the connections to see if that will help. Also I will disconnect the battery and reconnect all the connections that I have touched, also checking all the fuses, do all the groundings as stated above, reconnecing the battery and see if that will do anything. I need this car by tonight because I have class to go to and I need college in me to keep me out of trouble :-/

I really appreciate all your help and I tried applying all my knowledge and processes in case people try and Google this with a no start, no spark problem from a Honda Civic.

After talking with the aircraft electrician, he said it sounds like a ground issue somewhere. Especially if when I purchased a new dizzy, it fired up and the next day it didn't. Then going back to autozone for an exchange to only crank again. So we are going to do that and also the fuses while the battery is disconnected. Hopefully that will help.

I also did not see an alarm that turns off the ignition anywhere, so I ruled that out as well. Also noted, they said not disconnecting the battery would not short out my ECM.

You have had some introduction to Honda Civics. In my mind, your Civic should run. Apparently, you have an "open" somewhere or the ignition switch is bad and the ECM is not getting power. Thanks for your response, professional attitude, and service to your country. God bless.

The D-Harness is the molded connector on the right with 22 sockets.

.. .
.. .

As you look at the pins on the ECM, D19 and D21 are the last two pins on the bottom row.

If the car turns over, then would that rule out the ignition switch right? As I am at work now, I am contemplating what is wrong and asking others some questions. The only reason I think the pins are not throwing and voltage is because there has to be an open somewhere. Personally, I feel it has to be a ground because my wire harness looks great. I will keep you posted as to what the outcome is with mechanics looking at my car after work. Actually, I have to go now because the pilots need something and the bird is rotating and ready to fly...

No. "ON" is one circuit through the main relay and "START" is a different circuit. ON and START have different contacts in the starter switch. Power flows from the battery, through the ignition switch, to the under-dash fuse box, and to the ON or START circuit of the main relay.


Thought: You have no power to the ECM because the first relay in the main relay is not being energized.

The main relay actually contains two individual relays. One relay is energized whenever the ignition is on which supplies the battery voltage to the ECM, power to the fuel injectors, and power for the second relay. The second relay is energized for 2 seconds when the ignition is switched on, and when the engine is running which supplies power to the fuel pump.

Test: Turn ignition to ON and listen for the "click" of the first relay.

Nothing, I have nothing. After all my hard work I get nothing. I had the Chief Aircraft Electriciansmate help me, he knows his stuff and fixes aircraft, still rotating mind you while there is Navy Seal Team awaiting insertion, before they take off and I work right along side of him. I am at a complete loss, I have no car to get me around, I need a car to get to school tomorrow and I am ready to hit the bar to get ****faced via the bus.

I checked every freaking fuse, I pulled all the grounds, took a wire brush to the grounds along with the frame and bolts, I also pulled all my connections to make sure there was nothing inside blocking continuity also assuring that the pin was aligning with the connector to complete the electrical path too.

After all that, I put the key in, I only hear one click from the key switch, no two aditional clicks from the relay and I still freaking get the solid Check Engine light. I am going to check all my fuses again and try again. If that does not work, I am hopping on the bus to the bar. I bought this honda for reliability so I can actually focus on school and keep my mind clear, I never thought it would bring me down to this level. I really don't feel like burning all my paycheck on this car, I am totally lost. I don't get paid a lot and I do not want to spend my hard earned money I got saved from repairing aircraft in balad iraq all while getting mortered to just fix a Honda of all things.

The only is, it has to be the ignition switch

I'm sorry for your frustration, especially when you are trying to do the right thing.

See if it could be the throttle position sensor. Turn the ignition switch ON, disconnect the 3P connector to the Throttle position (TP) sensor, and wait several minutes and see if the CEL goes out. If the light goes out, replace that sensor.

Now, see if it could be the MAP sensor. Reconnect the TP Sensor. Turn the ignition switch ON, disconnect the 3P connector to the MAP Sensor, and wait several minutes and see if the CEL goes out. If the light goes out, replace the MAP sensor.

Nope, tried them both and the CEL still stays on along with the oil light (the only two lights that are on). Also with the ignition switch, I am leaning toward this. I am researching on how to test for this...

I doubt it is the ignition switch because all the article symptoms I read are pointing that the car would be fine, and randomly die on the road. My car cranks, with out the replays clicking, the CEL staying on and no spark.

Never give up!

If the CEL stays on, the causes are ignition switch, main relay (which we know is new) or the ECM. I agree that the ignition switch is not most likely. I still feel that it's the ECM. I like Cardone remanufactured ECMs, with a lifetime warranty, from O'Reilly Auto Parts. Get them to match Advance Auto Part's price and get the lifetime warranty. Put a new one in (10 minute job) and I bet your car starts and runs like a top. Remember to disconnect the negative battery cable before installing. If it's not your ECM I will be greatly surprised. I don't believe that it will be a connectivity problem--I haven't seen it yet on Hondas. They have good wiring and connectors. It's the core electrical stuff that wears out--ECMs, main relays, ICMs, and coils. Those are the usual culprits I've seen. To me, the odds are 90% that it's the ECM. I've wasted lots of time checking connectivity issues over the years--I was usually barking up the wrong tree. These Honda ECMs are not bullet-proof. Heat, vibration, and water trashes them. I've been told the electrolytic capacitors on the 1989-94 Civic ECMs are prone to leaking.

I do not plan on giving up, I just am really low on money right now and I do not have a lot to work with other then the money in savings for which I need in case of emergency.

There is not O'Reily autoparts stores around me. I am going to shop around for the cheapest ECM covered under warranty :-D

Thank you for all your help. I really appreciate everything you do for others helping them as well as myself.

First thing tomorrow is me hitting up kragen auto parts to get an ECM with a 1 year warranty for $260.

You are a great American and it is I who appreciate everything you are doing to protect this nation, during this very difficult period in our history.

My bet is you are stationed in San Diego. I know Kragen Auto Parts is all over California. I used to work at the Pacific Missile Test Center, Point Magu, CA.

No one in the san diego area has any in stock. I tried Kragen, Auto Zone and Napa :-/

davin, go to the site below, order the computer, and request 2 day delivery.

http://www.partsamerica.com/ProductL...ine%20Computer

Is the original ECM Honda Part No. 37820-P06-A50?

Try:

http://www.partsamerica.com/ProductL...ine%20Computer
Or
http://rockauto.com

OK, so all day today (I have off from work from doing work-ups from the weekend) I have been working on this car. I have a co-worker who has a 1993 honda civic LX automatic and I took out his ECM from his car and put it in mine. I disconnected the battery and everything and when I went to turn the key, no clicking from the relay and the CEL still stays on. Then when I put the same ECM into his civic, it fired right up!! Now I am thinking it could be the ignition switch, I have no other ideas :-/

Only thing else I can think of is some sort of interlock associated with the transmission or antitheft device. Pretty unbelievable.

Did your Electriciansmate look at it?

Yeah, he really could not figure anything out because all my grounds are good, my wire harness looks good, and my battery is at 12volts. He is also ASE certified I might add. He took a fluke to a lot of the goodies and everything read fine. We where also going to try the 12volt light bulb test, but we forgot it :-/

I am about to look at the switch right now and see if it looks pitted or anything. I think it may be that because my low beams do not work as well (the bulbs are new and the fuses are good, I was thinking it was the switch, but it could be an open leading from the ignition switch). This is the only thing I can think of :-?

Check these sites out on Honda ignition switches:

http://www.tegger.com/hondafaq/ignit...tch/index.html

http://techauto.te.funpic.org/ignitionswitch.php

*goes out and hotwires the car*

It has to be that because it says that if you do not hear the clicking sounds of the car, then it is the ignition switch!