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No spark at plugs or distributor?

Tiny
KHLOW2008
  • MECHANIC
  • 41,815 POSTS
Was anything done prior to this occurring?
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
ROSADOERICK
  • MEMBER
  • 2 POSTS
I haven't checked TDC sensor, where is it located? Today I checked the ELD, I read that if there's less than 4.5 volts that I have to check my ECU that it might be fualty. The computer still gives me 20 blinks, should I get another ECU? How can I test it?
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,815 POSTS
CODE 20 - ELECTRIC LOAD DETECTOR

1. Turn ignition off. Remove hazard fuse in main fuse panel for 10 seconds to reset ECU. Start engine and observe "CHECK ENGINE" light. If light is off, problem is intermittent. Test drive and check again.

2. If light is on, turn ignition off. Open lid of main fuse panel in engine compartment. Disconnect 3-wire electrical load detector. Turn ignition on. Measure voltage between Black/Yellow (pos.) And Black (neg.) Wire terminals of harness. If battery voltage is present, go to step 4).

3. If battery voltage is not present, measure voltage between Black/Yellow wire and ground. If battery voltage is now present, repair open in Black wire between connector and ground. If battery voltage is not present, repair open Black/Yellow wire between No. 14 fuse and connector.

4. Turn ignition off. Connect ECU test harness between ECU and ECU connector. Disconnect connector "B" from ECU side only. Connect Green/Red terminal of load detector harness connector to ground. Check for continuity between ECU terminal B19 and ground. If continuity does not exist, repair open Green/Red wire between ECU connector terminal B19 and load detector connector.

5. Reconnect connector "B" to ECU. Turn ignition on. Measure voltage between Green/Red (pos.) And Black (neg.) Terminals of load detector harness. If 4.5-5 volts is present, go to step 7). If 4.5-5 volts is not present, disconnect "B" connector from main wiring harness, not ECU. Measure voltage between terminals B19 (pos.) And A18 (neg.)

6. If voltage is now 4.5-5 volts, repair short in Green/Red wire between ECU terminal B19 and load detector connector. If voltage is not 4.5-5 volts, substitute a known good ECU. If correct voltage is now available, replace original ECU.

7. Reconnect load detector connector. Measure voltage between terminals B19 (pos.) And A18 (neg.) Under the following conditions.

I) Headlight switch in first position - Voltage should be 2.5-3.5 volts.

Ii) Headlight switch in second position - Voltage should be 1.5-2.5 volts.

8. If voltage is not as noted, replace faulty electrical load detector. If voltage responds as indicated, substitute a known good ECU. If condition is rectified, replace original ECU.
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
HARLEYWIZ
  • MEMBER
  • 1 POST
  • 1983 HONDA CIVIC
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 75,000 MILES
Ok I read evey where and tryed everything this is my only hope :) car wont start brought it home keep playing with it and it started ran good 3 minutes and stoped wont start again no spark
replaced new ecu/new relay/new distruber/map has 4.9 volts distruber coil has 12 volts rotor turns no spark all so new wires and plugs just ordered new key swich all fuses are good ecu has no led both sides of case are solid opend ecu no led inside so dont no codes sure could use some help on what else to check
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
DAVE H
  • MECHANIC
  • 13,383 POSTS
Have you checked/replaced ignitor/ICM


https://www.2carpros.com/forum/automotive_pictures/266999_ig_2.jpg



also check Main Relay (PGM-FI)
If vehicle starts and continues to run, relay is okay. To test, remove main relay, located under left side of dash. Using jumper wires, connect terminal No. 6 to battery voltage. Connect terminal No. 8 to ground. See Fig. 8 .
Fig. 8: Identifying PGM-FI Relay Terminals
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between relay terminals No. 5 and 7. Continuity should exist. If continuity does not exist, replace relay. Disconnect battery leads. Repeat measurement. Continuity should not exist. If continuity is as specified, go to next step. If continuity is not as specified, replace relay.
Connect battery voltage to relay terminal No. 5. Connect terminal No. 2 to ground. Check for continuity between terminals No. 1 and 3. Continuity should exist. Disconnect battery leads. Repeat measurement. Continuity should not exist. If continuity is not as specified, replace relay.
Connect battery voltage to relay terminal No. 3. Connect terminal No. 8 to ground. Check for continuity between terminals No. 5 and 7. Disconnect battery leads. Repeat measurement. Continuity should not exist. If continuity is as specified, relay is okay. If continuity is not as specified, replace relay. If fuel pump still fails to operate, test main relay harness. See MAIN RELAY HARNESS under FUEL CONTROL under FUEL SYSTEM.
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
DAVE H
  • MECHANIC
  • 13,383 POSTS
Check for codes ..and let me know .. count flashes ...

RETRIEVING CODES
With ignition off, insert jumper wire in service check connector terminals, located behind right side of dash. See Fig. 1 . Turn ignition switch to ON position. Diagnostic Trouble Codes (DTCs) will be indicated by a series of long and short flashes on MIL. The number of long flashes indicates the number in the 10s column. The number of short flashes indicates the number in the 1s column. For example, 4 long flashes followed by 3 short flashes would indicate DTC 43.


https://www.2carpros.com/forum/automotive_pictures/266999_jump_1.jpg

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+1
Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
GREASYFINGERS
  • MEMBER
  • 5 POSTS
  • HONDA CIVIC
I have a 1987 honda civic, carbureted 1.5 engine.
I am battling with an idle misfire that I can't seem to resolve.
Heres how it looks, the idle fluctuates rather than holding steady by maybe 100 rpm, Intake vacuum is not steady but bounces between 17.5 and 16.5 "hg, it does become steady at higher rpms. The exhaust pressure at the tailpipe is steady for a few seconds and then makes a "puh" when the pressure falls off.

I checked my O2 sensor output voltage and it seems to indicate a lean condiition at.1 volts, but closing off the choke makes the sensor respond quickly up to.9 volts. I put a spark plug test light inline with each spark plug 1 at a time and the lamp glows pretty steady but will occasionally glow brightly. When I rev the engine up to say 2k rpm the lamps is always bright and there is no sign of a misfire.

New plugs, cap, rotor, wires.
In desperation I replaced the ignitor.
Plugs are denso, cap and rotor are quality parts, the wires are the top shelf wires from aurtozone.

I suspect my carb is the cause of the lean condition, but the weak spark has me concerned that my distributor may be shot.

I checked the ignition coil resistance and it is really close to dead on with the factory service spec, I pulled the coil wire from the cap and the spark jumped about an inch and was reddish blue. I then pulled the wires (at the cap) to each plug and they acted the same, they would jump about an inch and were the same color as the coil spark. The wire that had the test light in it seemed to give a brighter glow when I held the connector a little out of the cap.

What should I do?
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
BRUCE HUNT
  • MECHANIC
  • 3,753 POSTS
Are you getting a PGM-F1 light? Have you checked the PCV valve? Can you narrow it down to a particular cylinder that is causing the problem? I am suspecting a vac problem. I am not too familiar with a carbed Honda car engine but there are several things that I think about. You mentioned the lean and that could be a timing issue. Try looking at the timing and vac lines, etc. See if the timing makes any difference to the idle.
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
GREASYFINGERS
  • MEMBER
  • 5 POSTS
There is no light for this one since it isn't fuel injected. More history on the car, I got it with a blown head gasket and shredded waterpump. I replaced the gasket (checked the head, ok) and the waterpump/timing belt. I also replaced the PCV while I had the Intake Man off. Afterward I replaced all the typical maint type items fuel/ air/ oil filters, cap/rotor/plugs/wires.

I have adjusted the valves to spec and the valve seals were replaced when I did the HG. I do have 2 cyl with lower compression, but the deviation is within spec (20 psi from the highest cyl, max is 28)

I did have a vac leak at the carb insulator which I replaced and no longer get any feedback when spraying carb cleaner aroung the intake manifold and vac hoses. I still think my vacuum is low, but I cant easily find out why. I have checked my EGR which is not funtional due to leaking diaphragm but the valve is clean and stays closed

I get the same results with my spark tester on all the cylinders, dim glow and occasional bright glow, so I haven't been able to catch one cylinder missing occasionally that way. The miss seems to be random.

I have the timing set at the 15 deg mark on the crank pulley but it bounces due to the idle problem.
I had it really advanced and that was bad, should I try retarding it?
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
BRUCE HUNT
  • MECHANIC
  • 3,753 POSTS
You mention the EGR valve and that it stays closed. I found this and am wondering if the valve is possibly causing some of the problems.

"If it sticks in the open position or fails to close all the way, it acts like a vacuum leak resulting in a rough idle, hesitation and possible stalling."
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
GREASYFINGERS
  • MEMBER
  • 5 POSTS
I had the EGR valve off and cleaned it up today, it moves freely and the spring seems to hold it closed. Still acts the same.
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
BRUCE HUNT
  • MECHANIC
  • 3,753 POSTS
One other thought; you said you had the intake manifold off. Did you put on a new intake manifold gasket? I have experienced a rough idle and surging on the FI engine, due to a leak at the intake manifold. A fragment of old gasket can cause a leak of air that mixes with the fuel.
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
GREASYFINGERS
  • MEMBER
  • 5 POSTS
I replaced the gasket since it came with the headset, I did a pretty good job of surface prep as well. I sprayed down the top of the IM with carb cleaner looking for leaks, but I will try getting at the bottom as well
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)
Tiny
GREASYFINGERS
  • MEMBER
  • 5 POSTS
After several more hours of poking around, I have determined that the spark is the same all the time and not the reason for the misfire. I don't know why I get an occasionally brighter flash.

I retarded my timing a bit so that when I artificailly richen the mix by shoving my finger into the idle secondary venturi, the timing is dead on and rock solid. Of course as soon as I take out my finger it advances and jumps around.

Last intake vacuum reading was nearly 20" but the idle may have been a bit high.

Any vacuum leaks are either tiny or internal and will be devilish to locate as the last 2 were.

I may just rebuild the carb in desperation, but first I am running a tank of gas treated with seafoam.
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Monday, November 2nd, 2020 AT 2:02 PM (Merged)

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