I bought this car a few days ago. The previous owner said that the car was having an idle problem, so I figured cleaning out the IAC Valve and the Throttle body would solve this.

Prior to buying the car, during the test drive, the car would die when approaching a stop. Clutch was all the way in and the car would still die. It would start right back up with no hesitation.

Bought the car, drove it home, let it sit a few days. Took the Throttle body out of the engine and cleaned the throttle body and the IAC Valve. Sprayed them with a throttle body cleaner as well as an electronics cleaner. Put everything back together and now the engine won't start.

I have checked the spark plugs, changed them actually, changed the distributor cap and rotor, changed the MAP sensor. Still not starting.....checked all the fuses, all are fine.

Last thing I did was to take out the Ignition Coil to test the Ohms...it's not reading as it should (according to the book), but my friend is thinking maybe the Ohm meter is not working properly...I will take in my ignition coil to have another reading done, but...if my ignition coil was bad, wouldn't a CEL come on?

Also, how could taking off the throttle body cause the Ignition coil to all of a sudden stop working? Or is this just a coincidence?

Any help or insight will be greatly appreciated...

 

Your meter probably isnt off. You can test it by putting your 2 leads together, they should have less than an 1 ohm of resistance. Does the car crank but just not start?

 

Check for spark. Grab and extra spark plug. Pull the #1 plug wire from the head and stick the spare plug in it. Then put the spare plug to a bare metal engine ground and have someone crank the motor over. The spark plug should make a visible spark. If not, there could be another problem.

Also, main relay could be causing this problem:
http://mustardcat.brinkster.net/p3g/.../mainrelay.htm

 

Probably the coil. They just die all of sudden.

 

As mentioned previously, test to see if you have spark with a spare spark plug. If no spark then try this.

Do you have a test light, I like to do this at night. Ground the test light like normal, probe the coil negative terminal, crank the engine, if the test light pulsates, then the ignitor or ignition control module should be good and its time to get a coil. This is a good test but not 100%, a dwell meter is needed to be 100% sure but most folks dont have one, I believe the minimum spec is about 4 degrees of dwell to allow the coil enough saturation time to produce a spark, this is with a good coil of course. More than 4 degrees of dwell and no spark equals bad coil, less than 4 degrees of dwell means bad ignitor, no dwell, go hunting.

You cannot trust an ohm meter to test a coil, it will only tell you that the coil is not an open circuit, any other readings is a guess. Even if you have spark outside of the cylinder, that does not mean that the spark is strong enough to work under compression, yes, it takes more energy to create a spark under compression and even more energy under compression with a lean air/fuel ratio. This is why you need a true spark tester tool to test spark outside of the cylinder. E=MCsquared.

 

You might want to check the compression. Just a thought.

 

If the car doesn't even crank over then your ignition switch could be bad the 5th gens had a recall because of that. If it does then test everything spark and fuel. And you may still have an idle issue if your iacv is bad, cleaning it doesn't always fix the problem you might have to replace it.

 

Thanks for all the replies. The car cranks, but doesn't start. I will do the tests that you have all suggested. I will keep you posted. Thanks again for all the responses.

The ignition switch, is that an easy switch if it's bad?

 

It is fairly easy. Just the electronic portion of the ignition, not the entire ignition assy. Its the electrical switch portion behind the main key portion.

 

Thank you. I'm still waiting for my battery charger to arrive. I'm draining the battery as I'm trying to start it...
Tomorrow I'm going to replace the TB with a TB I found from the same year and model car. It is in working condition. So if this doesn't work...I'm at a loss. I didn't touch anything else...so hope this works! Keep y'all posted.

 

Okay, here's an update. I ended up having to buy another battery. My old battery wouldn't even charge.

So I replaced the TB assembly, reconnected everything, connected the brand new battery....still no start.

My uncle helped me test for spark again, from having a weak spark before, now I have no spark at all. We tested the wire going into the distributor cap, no spark, so we tested the ignition coil, no spark from there. So now I'm going to test the ignition coil. I've been using the Chilton's manual so far, but it's for an accord and Prelude...does anyone know the Ohm range that the ignition coil should be between? I'm waiting for my original Prelude manual to arrive, but just thought if anyone knew the range. Thanks.

 

Helms manual, page 4-20.

Download from www.spoonertuner.com/manuals

 

Thanks for the link. I've been waiting 2 weeks for my manual! I'll check it out when I get home. Thanks again.

 

Dont trust your coil ohm readings, its not a good test, unless its OPEN. Look at my test above.

 

Okay. I'll try out your test as I don't want to waste my time with the ohm meter if it's not going to tell me much. Thanks. I'll update soon.

 

Update: coil is dead. So I'm ordering a new one. I'm also ordering a new igniter as well, since they said those tend to go bad as well.

Question though: does anyone know where the grounds are in the engine? I know there are multiple ones, but I want to check those out...just in case one has come loose or something. I've read in other posts that they went through all the hassle of ordering new parts and then the problem was a ground wire somewhere.

Thanks.

 

1. direct from minus lead of acumulator to the gearbox
2. direct from minus lead of acumulator to the chassis (in front)
3. drivers' side engine mount to the valve cover

 

Thanks! I've checked 2 of the 3. I'll check on the gear box one. The other 2 were fine.

 

Checked and cleaned grounds. Changed out ignition coil. Still not starting. Any other suggestions? I'm really at a loss at this point...

 

im curious to this as well. im having a similar problem with my ef.

 

Hello, You Can Also Go To Your Local Parts Store And Either Rent Or Buy Some Noid Lights And You Will Be Able To Check The Injector Pulse On tHe Injectors And That Will Tell You If Your TDC Sensor Is Working And The Computer Is Receiving The Signal To Pulse The Injectors. If You Have Injector Pulse , Go To The Ign Coil and Distributor.

 

Do you not have spark, no fuel, no fuel injection or a timing problem, mechanical and electrical, lets not forget compression, do a wet compression test, you have been cranking so much that you could have washed down the rings and there is no more oil to help with compression. You dont only check for the big three these days, its much more complicated than that now. Let us know what you find.

 

Changed out my igniter. Tried starting..it didn't start at first. I had to pump the gas pedal a few times...then eventually just held the gas pedal to the floor and attempted to start. Finally, it started!!! But as soon as I release the gas pedal, engine dies. Hold the pedal to the floor again, engine starts. Could this be a bad IAC valve? Or do I need to reset the ECU by pulling the clock fuse?

 

Keep it running long enough to get some oil pumped throughout the engine and burn off the excess fuel in the cylinders, then see if it will idle. If not, clean the throttle body and IACV and see what happens next. Make sure you dont have any major vacuum leaks too.

 

Okay, so I have tried to start the car up again, won't start again. Checked the battery, hoses, grounds, etc. everything is still connected as it was. I'm at a loss....