Hello,
Before I posted this thread I reviewed few threads that could help me in troubleshooting the problem of my car (1990 honda accord ex) but unfortunately it got to a point that I needed to post this new thread. I may have missed a thread that helps but anyway I’ll just post this just in case. First, I purchased this car 2 years ago and was running great. One day (two weeks ago) I drove it to the mall, after shopping got in the car, tried starting the car and would not start. It cranks but just won’t start. Fuel gauge is showing 1/8 tank. I thought I had a damaged fuel pump so I ordered one. Never installed it because I guess it was worth troubleshooting first before doing any hard labor and if I needed to, the fuel pump is ready to install.
I picked up few tips from this forum how to troubleshoot.
1. The air filter been replaced 5k ago and the location of the area I’m at is not very dusty.
2. The timing belt had been replaced 10k miles ago.
3. Just to be sure the timing belt is still intact removed the timing mark cover and had someone turn the engine on and while cranking there is movement. So I think this ok.
4. When key is turned on, the CEL and the S light turns off after few seconds.
5. Checked all fuses under the dash and under the hood and looks good.
6. Checked fuel delivery system as listed below.
a. When the key is turned on, I could hear the fuel pump priming but to be sure I removed the main relay and resoldered the solder joints. Checked for continuity and voltage throughout the main relay and everything checks ok. Also double checked the voltage at the fuel pump harness and looks ok, measured near 12v.
b. Purchased fuel pressure tester and checked fuel pressure at the fuel rail and measured 39 psi. This tells me that the fuel pump for sure doing its thing, no clog on the fuel line or fuel filter.
c. Checked the fuel injector resistance and measured 2.5 ohms.
d. Checked the resistance at the injector resistor terminals and measured 6 ohm to all 5 terminals. This seems ok.
7. Checked electrical as listed below.
a. Checked fuel injector wire harness for voltages. Measured near 12v for each harness.
b. Checked spark at spark plug. Looks ok but replaced with new ones (NGK ZFR5F-11).
c. Plug wires measured less than 12k ohms and this seems ok.
d. Replaced rotor and rotor cap but the car still would not start.
At this point, I’m stuck. I’m not sure what else I should check/replace. Could someone please help?

 

It sounds like the fuel side of things is fine with 39 psi at the rail. The injectors could not be opening. You can plug a test light into both terminals of each injector connector and see if it flashes.

You said that you checked for spark and it looked ok? You were a bit vague on that point. It is likely that you have either a bad coil or bad ignitor.

I was involved in a thread where someone saw adequate spark when the pulled a plug and tested it grounded on the engine. You should have a bright white/blue spark.

We went through numerous tests and nothing made sense for his no start. He hooked up a timing light to the wires, and the current generated by the coil wasn't enough to throw the timing light. If you have a timing light, hook it up to the spark plug wires and see if it flashes. Test coil resistance as recommended in Haynes manual or the shop manual (you can download one for a 90 accord in the online manuals thread in DIY section). Bad coils can still test within the resistance limits in the manual.

There is a coil vs ignitor test in the DIY section as well.

 

https://www.hondaaccordforum.com/No_...m_52217/tm.htm

spark just looks ok ?? or it is ok ??

just for the heck of it , try the above procedure

 

thanks guy! i will double check the flashes from the injectors. also will be checking the coil and ignitor. by the way, the spark was near white/yellow ish color. guess this color is not really acceptable as so call spark? i will post what will the out come be.

 

so far there's one more thing i need to check as recommended is to check the injector with a test lite. but i wanted to know if i properly checked the coil and igniter. while checking the coil/igniter, the battery needed to be charged so i connected a jumper cable and had the other car running just to get adequate voltage to the dead battery (measured 13.5v) when troubleshooting. as recommended by DESERTHONDA, i used the method he had attached to his respond.
1) turn the ignition ON & check for MIL that it should come ON, then turns off after 2 sec. this was ok.
2) check for battery voltage at the positive wire going to the coil & positive wire going to the igniter. this was ok.
3) connect a voltmeter between the coil negative terminal and ground. measure the voltage between the coil & igniter wire connected then disconnected. while cranking, with wire connected measured 15v to 17v. with the wire disconnected measured 9v.

this is where i got confused because the instruction said if the voltmeter reads 8v with the wire connected and if the voltmeter reads 10v with the wire disconnected then to replace the coil. i measured totally the opposite. so just to make sure the coil is bad, i measured the resistance. at the primary terminals, i had the ohmmeter connected to the positive and negative and measured 1.1 ohm. then i measured 15.86k ohm between the positive terminal and the secondary winding terminal. now i'm thinking that the coil is good because the resistance is within spec. so i tried another approach by using test lite. i connected one end of the test lite to neg side of the coil and the other end to chassis ground. while cranking, if the lite flashes, then the coil is bad. the lite was flashing but not really heavily. probably because the battery was dying? but i still had the other car running while i was doing this troubleshoot just to keep the battery charging.

so my question now is the igniter the bad one? the instruction also mentioned that if the voltage measured 10v between the coil & igniter wire connected and disconnected then the igniter is bad. i measured 2 different voltages.

before replacing the coil or igniter, can someone please confirm that i did not miss any of the steps. also if you have any other way to check? would this also be a distributor problem too?

 

Is your coil part of your distributor or is it external?

I'm trying to figure out how you can test the ignitor. The ignitor has four wires going to it. There will be 2 wires that have 12V when the ignition switch is on. One is the the blk/yel wire. That is the power source from the ignition switch. The other wire with 12 V will be connected to the B(-) terminal of the coil and I do not know the color of that one. This wire is grounded by the ignitor (by ECU control) and charges the coil.

Another wire will have 10V and that is the ECU control of the coil and should be yel/grn. The last wire is what generates the tachometer signal and I do not know the color of that wire either.

With that said. Unplug the two wires that connect to the coil (or the wire harness that feeds it) and remove the wire that connects to the B(-) coil at the ignitor. You need to hook up a test light between the the terminal of the ignitor that plugs to the B(-) terminal of the coil and the yel blk wire that goes to the A(+) terminal of the coil. You are basically taking the coil out of the circuit and hooking up a test light there.

Have someone try to start the car. That light should flash.

If it doesn't, keep the coil disconnected (or you will definitely damage it). Use your volt meter to verify that the pin going to B(-) terminal and body ground has infinite resistance to verify that the ignitor isn't constantly grounding the coil. Also connect a test light to the yel/grn wire (removed from ignitor) and ground. Have someone try to start the car. That light should flash as well.

 

thanks pahonda. the coil is internal of the distributor. i will try this method and will post the out come.

 

confirming that the ignitor is delivering battery voltage to the coil. first i followed pahonda instruction is to disconnect both terminals going to the coil. second is to measure the voltages on each terminal from ignitor. turn on ignition key without cranking the car. connect one terminal of the voltmeter to black/yellow wire (+) and the other is to a chassis ground. measured 12v. third is to removed the voltmeter probe connected to blk/yel wire (+) and place it to white/blue wire (-). This wire goes to neg of the coil. Again this wire should be disconnected from coil when measuring the voltage. Measured 0v. Just to be sure that the ignitor is the problem, i measured the continuity on the wire that connects from ignitor to coil and measured zero ohm which now tells me that the ignitor is bad. I ordered the ignitor and will arrive on tuesday. will post the out come.

pahonda, thanks for specifying the ignitor's four connectors which helped a lot when troubleshooting. also to disconnect the wire going to coil which made more sense when measuring the voltages.

previous troubleshooting, this was the mistake i did which i did not disconnect the two wires that are going to coil. if connected, you will measure 12v to each terminals.

 

Hold on a sec.

Did you measure voltage on the white/blue wire only disconnected at the ignitor (still connected to the coil)? That should have 12V. If the wht/blu wire is disconnected at the B(-) terminal of the coil, then it should have 0V. The ignitor grounds the wht/blu wire to charge the coil.

Plugging the test light between the wht/blu and yel/blk wire (where they connect to the coil) will be the way to confirm that the ignitor is grounding the wht/blu wire. It should flash when you try to start the car.

 

Sorry for the confusion. i disconnected both wires (wht/blu and yel/blk) from the coil terminal by unscrewing the bolts. the wht/blu wire were connected to igniter and this is where i measured zero volt between igniter B(-) and ground.

connected test lite between wht/blu and yel/blk wires (connected to igniter) and it flashes when starting the car. the coil is still disconnected from igniter. measured resistance between igniter (B-) wire and chassis ground and resistance is 23k ohms. but should this be infinite, so called open circuit, correct? note that while measuring the resistance, it did not matter if the ignition key is on or off. also just for the kicks of it, disconnected the yel /grn wire and remeasured the resistance between igniter (B-) wire and chassis ground and no change. resistance is the same. next, connected a test lite between yel/grn wire and chassis ground. while cranking the car, there is no flashing light to the test lite.

so now I’m thinking could this be a ECU and igniter issue? I went to purchase a Haynes repair manual but do not specify how to troubleshoot the ECU. Just replacement procedure.

Please advice to how to troubleshoot the ECU or if you have other advice to what else to check. Also please confirm if the igniter is no longer an issue. Just because I measured resistance to B(-) of the igniter, I am not sure at this point.

p.s. i hesitated on the igniter order until it was confirm that this is the problem.

thanks.......