Cranks, but wont turn over. 95 Civic DX

GlennH

New Member
First of all I checked all the old posts regarding no start problem.

Car has 40k original miles and ran great. Excellent car. Yesterday morning, went out to start it. Able to crank the engine but it doesn't start.

Battery is fine.
Checked for spark and there is spark.
Cleaned and tightened the ground on the thermostat housing.
I checked all the fuses, both under the hood and under the dash. All were fine.
Checked the main relay and all soldering points look excellent. No cracks detected. The car was in a mild California climate until 2014 when it came to Arizona

When put key on the ONII position (but without trying to start the car), I couldn't hear the fuel pump prime.

Based on this helpful post http://www.clubcivic.com/forum/threads/no-power-to-fuel-pump.210565/

I did the following.

Removed the main relay under the dash and connected Terminal A1 to Terminal A7, using a wire. I could hear the fuel pump run, even without having the key in the ignition

Then I connected Terminal A5 to Terminal A7. I could NOT hear the fuel pump run.

Next, with the main relay in place:
  1. Turned key to ON(II).
  2. Grounded the A7 and then A8 terminal (Grn/Yel wire) individually to the metal frame under the dash.
When I grounded A7 nothing happened.
When I grounded A8, I could hear the fuel pump.

Since the fuel pump is running, I'm guessing the fuel pump is not the issue.

How can I determine whether the issue is the main relay under the dash or the ECU unit? or maybe there is some other issue?

Also, in the link to the helpful post that I noted above, it indicates that fuse 24 and fuse 31 should be checked.
Does anyone know what these fuses are and where they are located? The fuses under the dash only go up to fuse 27, and fuse 24 is for the electric window. Also, I don't find a fuse 24 or 31 under the hood.

Thanks for your help
 

GlennH

New Member
Thanks boofoo, really appreciate your help. I changed out Fuse 24 this morning (the original fuse looked ok). Still the car only cranks but wont start and run. I listened, and the fuel pump still doesn't prime.

Also, when I turn the key to the ON(II) position, I think the main relay clicks once. Hard to verify this, but fairly certain.

Any other ideas about how to continue troubleshooting the problem?
 


GlennH

New Member
Actually the old fuse was still ok, and the new one is also. Just to make sure, I replaced Fuse 24 a second time, because I have several spare 15A fuses. Bottom line, I think the fuse is ok.

But should I check the voltage anyway and report back?

I really appreciate the help, I'm in a remote part of Arizona and it is my only car. So I'm stuck until I get it sorted out.
 

GlennH

New Member
I pulled Fuse 24 and took a reading with the multimeter at the connections for Fuse 24. 12.3 Volts

Previous to this morning, when I had the key in the ON(II) position, the CEL light remained on, even when the key was left in this position for five minutes or so.

After I placed back Fuse 24, I still had the key in the ON(II) position. Then approximately two or three minutes later I heard the fuel pump prime and the CEL light went off.

Tried to crank it and the car started!

Then I turned the key off and tried again. I noticed that now the CEL light stays on approximately 5 seconds or so and then the fuel pump primes. Did this several times and there is a short lag before I can start the car. Don't recall the short lag, I just used to put the key in and crank, and it would start right away.

Anything else to check, or is the problem resolved now?


 

GlennH

New Member
boofoo, you must be a Honda expert. Thanks again, for helping.

Actually, I spent quite some time trying to get a voltage reading with Fuse 24 installed, trying to take the voltage at the top taps, but I couldn't really get a good reading. Sometimes it would flash a number for a split second, but usually I was only able to read 0 volts. I can go out and try again. What do you think?
 

GlennH

New Member
The two test results above are inconsistent with one another. Most likely the first test (5-7) yielded a false negative result.

The delayed time for the pump to prime is most consistent with a bad ECU, assuming that voltage at both top tabs of installed fuse 24 identically read battery voltage. You have not yet posted those test results.
Regarding: The two test results above are inconsistent with one another. Most likely the first test (5-7) yielded a false negative result.

Possibly I did not have the connection wire properly in place, although I tried several times to make sure I had a good connection. I couldn't really see if I had a good connection or not, as I just stuck the wire in place. Should I try that test again? If so, with the power on ON(II), I assume?
 

GlennH

New Member
Touch the red meter probe to one fuse tab and the black meter probe to the metal frame under the dash.
My bad, I had better go back and review electricity 101.

Anyway, with the key in the ON(II) position, Fuse 24 reads 12.3 Volts.

Just to check, I left the key in the ON(II) position and after approximately one to one-and-a-half minutes the CEL light went off and the fuel pump primed.
 

GlennH

New Member
Thank you. Are you 80% or more sure that it is the ECU? I think they are fairly expensive.

Also, what pointed to the ECU being the problem?

Also, can I PM you in order to send a small check for your help?
 

GlennH

New Member
95%

Does your Civic DX have a D15B7 engine? If so, it should not be inordinately expensive.


That's very kind of you. Thanks. I'll PM later when the current tech discussion is done.
Re: Does your Civic DX have a D15B7 engine?

I believe that is correct. It is a stock 95 DX model. I'll start a new threat to ask about the best place to buy an ECU, etc.
 

GlennH

New Member
Your A8 test result where the fuel pump ran localized the problem to the ECU or its circuit.

The delay in the CEL turning off and the pump priming after turning the key to ON(II) points to a faulty ECU.
I'm guessing that it is best not to drive the car until the ECU is replaced, due to the ECU possibly completely failing at any time now.
 

GlennH

New Member
Took out the ECU a couple of days ago and looked at both sides of the circuit board with a magnifying glass. All soldering joints looked new as far as I could tell and the C14 (fuel pump related) capacitor and other capacitors looked excellent, no bulging or leakage.

Went to reinstall the ECU this morning (72 deg F ambient temperature) in order to find out if any codes were coming up on the CEL. When I turned the key to the ON(II) position, the fuel pump primed right away and the CEL engine light went off. Then twice I turned it off and turned to the ON(II) position, with the same result. This afternoon (90+ deg F) tried again to find out if the increase in ambient temperature made any difference. The first time with the key in the ON(II) it took approximately 5 or 10 seconds before the fuel pump primed and the CEL light went off. The second and third time in ON(II) position, the fuel pump primed right away and the CEL light turned off.

Tomorrow I'll repeat what I did in the paragraph above and find out if the results are similar.

By the way, the CEL did not throw any codes.

Any more advice or is the ECU still the main suspect?
 

GlennH

New Member
Repeated yesterday's test:

When I turned the key to the ON(II) position in the morning when it was cool, the fuel pump primed right away and the CEL engine light went off. Repeated this three times, with the same result. This afternoon (90+ deg F) tried again with the key in the ON(II) it took approximately two minutes before the fuel pump primed and the CEL light went off. Then tried to start the car and it fired right up. While waiting for the pump to prime and the CEL to turn off, I jumped the code plug (located the glovebox) with a wire. The CEL did not throw any codes, but the SRS light (which is working correctly) blinked continuously while the wire was in the code plug. It was not a series of long and short blinks, just a steady blinking. Tried to look up this issue on the internet, without much luck.

So the issue of the fuel pump not priming definitely appears to be temperature related.

Even though the C14 capacitor (associated with the fuel pump) on the ECU looks good, I'm considering replacing this capacitor on the ECU circuit board to see if that solves the issue.

Any recommendations or thoughts?
 

sycokid666

Respected
My 95 hatch is kinda having this issue as well I am curious on seeing what happens. I get mine to prime by opening the gas cap and releasing the pressure and for some reason it primes up and starts right up and it seems like the steering wheel tilt has to be all the way up not sure if that has anything to do with it but similar symptoms of the no prime no start I don't get any cel codes when I do start up though . I thought it was just faulty wiring or something to do with one of the wires to the ecu but they all look fine . Note: this car has a b18b1 using a 91-93DA ecu and I just start it up to keep running or if I need to move it or something it's future project and not a daily..


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sycokid666

Respected
When the pump WON'T prime with key turned to ON(II), does the CEL remain on steady or does it turn off after 2 seconds?
I will check and get back with you boofoo I'm thinking it stays on for a few seconds and then turns off but not 100% positive got home late and don't want to mess with it I will check tomorrow when I get home from work ..


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GlennH

New Member
Original poster here.

I replaced the C14 Capacitor on the ECU (desoldered the old one and soldered in the new) and haven't had a no start issue during the last two days, so problem appears to be resolved. Recommend, for anyone who hasn't done so, replacing the C14 capacitor, as this one is known to fail in older ECUs, and failure could lead to a damaged circuit board. In my case the capacitor looked fine on the outside and circuit board was undamaged. If anyone needs a C14 capacitor, PM me and I'll mail one for three bucks, including postage. I have extras
 


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