[TxGreaseMonkey]

I believe both ECMs are bad. You should've read 5 volts! To me, this is why your Civic won't spark and ties in with the Check Engine Light staying on, when the service check connector terminals were jumped.

Remember, the MAP sensor 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 (basically, a giant power transistor), you will experience catastrophic ignition and fuel system failure.

[zortmo]

Is it odd that both ecm's measure the same voltages? Have you ever tried to repair the ecu? Do you know which chips go bad?

[TxGreaseMonkey]

That's way over my head. I've been told that, over time, the electrolytic capacitors start to leak on the 1989-94 ECMs. Heat is the big culprit. Do you see blue swirls on the covers? If you open them up, you may see several microprocessors that are "crazed" from heat. Vibration and heat can also affect these "giant circuit boards," just like Honda's main relays, causing cold solder joints. Buy a remanufactured Cardone ECM from O'Reilly Auto Parts for around $255 with a lifetime warranty. Other outfits only give you a 1 year warranty. Another alternative is to buy a used one on EBay for around $110, freight included. Some might come with a 1 year warranty. New ECMs from Honda are over $850, plus tax, and only have a 1 year warranty.

Where did you get the second ECM? Yes, it's very interesting. Both could have been damaged in the same way; e.g. not disconnecting the negative. Battery terminal when working with them. It's hard to tell.

Honda Civics will go 350,000 miles, if you take care of them. I keep my cars for a long, long time. If you like the car and would like to keep it for a long time, then I'd put a new ECM in it.

[TxGreaseMonkey]

You can perform other tests, but I don't think anything else will get it to spark. Tell me about how your problem began. Was it sudden?

[zortmo]

Yea it was sudden... going down the road about 45 and just died. I checked for spark and fuel first thing. I had no spark and I smelled fuel at the exhaust after cranking the engine over and heard the fuel pump as usual, so I figured I had fuel pressure. I opened the distributor and saw a small amount of oil inside. I figured it was enough to short out the igniter or ICM or whatever the heck it is. I bought a remanufactured distributor and it still had no spark. I returned the distributor and searched the net and found someone saying if I had a solid CEL on shorted service connector I had bad ecu. I also bench tested the main relay... it's fine. So I bought an ecu off Ebay for $90. I have an email to the seller to see if it can be returned. I probably get to eat it.

[TxGreaseMonkey]

Sudden death situations are often caused by computer failure. People think these ECMs (particularly Honda) are bullet proof, but they are not. Makes me think even more that its your computer.

Here are the likely culprits, when you don't get spark: ECM, igniter, coil, rotor, distributor cap, wires, main relay, and MAP sensor. ECMs and igniters are the usual culprits--both solid state. They either work or they don't.

[zortmo]

I really appreciate all your help. I'm also a believer in Honda. This is the first time one has laid down on me. I'm thinking about an buying an Insight. Maybe now is a good time.
Just thinking out loud here... do you think any other sensors / transducers being bad could cause this condition? (I understand there are other sensors that effect the spark... )

[TxGreaseMonkey]

If your car is in otherwise good shape, I wouldn't get rid of it. The MAP sensor is the "Key" sensor on Hondas and is the only one capable of knocking out spark and fuel. The same can be said for the ECM.

Somebody else will come along and get your car for a steal, put in a remanufactured ECM, and drive it for years. Trust me, I've seen other people get frustrated with otherwise fine cars and sell them to an individual who knows what he is doing for peanuts on the dollar. Good way to make a living, if you wanted to. You are on the verge of a great personal victory--don't stop now.

[TxGreaseMonkey]

How many miles are on your Civic?

[zortmo]

Ok,OK... I'll have to save for a couple of weeks for the parts. I'll post back after the next round. Thanks again
150,000 mi give or take... run hard and put up wet...

[TxGreaseMonkey]

Hang tough and never, never, give up!

[TxGreaseMonkey]

zortmo, here is what it would cost to replace the crucial ignition parts and get a new lease on life:

Ignition Coil (RockAuto.com), Part No. 30510PT2006, $36.79
Main Relay (RockAuto.com), Part No. RY422, $38.89
Igniter, Advance Auto, Part No. 115070, $69.88
ECM, O'Reilly, Part No. 722048, $256.99*
Total $402.55

* Have O'Reilly match Advance Auto's price and get a lifetime warranty for the same price.

[kean]

You may try to test both ecu to a same model car/engine and see if it works so you could isolate the problem with it.

I thought several times trading my honda to a corolla bacause toyota is known to be very reliable, but when I had the chance drive the corolla, I realized that I get more pleasure driving my civic, damn fast for a SOHC but economical.

I hope you've seen some souped and very well dressed civic around your place, I'm sure you'll think twice before getting rid of it. The EF,EG, and EK civics are good looking and I think even after 10years it will still be.

The good thing about having a problem like this is you learn about your car.
And if you encounter the same problem in the future, you already know how to solve it. Save money on labor cost.

Just change the crucial parts as txgreasemonkey had stated and you will feel your car perform like it was new. Anyway those parts are part of the car's service maintenance, don't be sad to spend few bucks, you will benefit from it in the long run.

[TxGreaseMonkey]

zortmo, try this test:

. Turn ignition switch OFF
. Reconnect the 3P connector to the MAP sensor
. Turn ignition switch ON
. Measure voltage between D17+ male terminal and D21- male terminal on the ECM
. Record the voltage and let me know the reading.

[zortmo]

Fixed it... finally. The first distributor I bought was bad. I got another one and it fired right up. I was able to rule out the ecu by using a logic probe to verify the signal between ecu and ignitor. It had to be in the distributor... I bought one from Oreilly with all new oem parts and a lifetime warranty for 175.00.
Thanks for the help and the inspiration to stay after it. Great forum.
Mike

[TxGreaseMonkey]

Good job. That's got to make you feel really great!

[Doug777]

I was having the same problem with my 92 civic not sparking. I finally figured out from this forum how to test the ECM by map sensor voltage and it tested bad. So I got a used one and it started up just fine and worked for a day. I ran a engine code test and got straight blinking... nothing I could discern different from long - short blinks. They all seemed the same to me and just kept blinking(Is there something wrong with that?). Now today I go to start it up after work and it won't start again. So I checked the engine code again and got a bad ECM signal.

So my question is, what is it that is killing the ECM? Is there a short somewhere that is frying it? If so, how do I diagnose it?

I've noticed for a while that every time I try to get out of my car I get shocked when I touch my door, which was annoying at least, but got me wondering if there was something wrong. Next thought is that the door locks randomly quit working and I don't remember being shocked before that. Could that be the culprit?

[TxGreaseMonkey]

Doug777, it's very important to disconnect the negative battery cable, before working on the ECM. You also should ground yourself first, so you don't short out the new ECM.

This link may help:

https://www.askmehelpdesk.com/cars-t...tml#post235038

[Doug777]

Doug777, it's very important to disconnect the negative battery cable, before working on the ECM. You also should ground yourself first, so you don't short out the new ECM.

This link may help:

https://www.askmehelpdesk.com/cars-t...tml#post235038

Yup... I read through all that before and did it all step by step. The negative cable was disconnected when I did the swap and I reconnected it afterward. I was also grounded to the car body when I did all the work. It ran and I drove it about 2 miles, put it to sleep for the night, and drove it another two miles to work in the morning. When I went to start it again when I was done working it wouldn't start and that's when I did the engine code check and got the bad signal.

Now I'm just trying to figure out what is causing the ECM to go bad? There has to be something screwing it up for it to be going bad after 15 minutes of driving.

[TxGreaseMonkey]

Doug777, was the replacement ECM an exact part no. match? When I replaced my ECM two years ago, I bought an ECM with a lifetime warranty from O'Reilly Auto Parts.

Try applying dielectric grease to the ECM's connectors.