Hi, I'm new here and searched for an answer before posting, but no luck so far.

My wife's '99 Honda Accord, 4 cylinder LX with 109k miles, will intermittently experience engine cut-out. She will be coasting down a long hill at about 40 mph, the RPMs will suddenly drop from around 2500 to below 1000, the engine check light will illuminate, then everything returns to normal as she steps on the throttle. It has happened twice in two weeks.

We took it into the Honda dealer where we bought it and the service department couldn't find anything wrong, and couldn't duplicate the problem.

My wild guess is that there is something in either the fuel injection sensing or engine management computer.

If anyone has an idea I'd certainly appreciate hearing it. The car will need to go back into Honda service, but I'd like to suggest to them an area to focus on since they couldn't find anything the first time.

Thanks!
JJ in Denver

 

What tranny? How exactly does she coast downhill?

If manual, & she doesn't press the clutch pedal, then of course the true engine RPM can't really drop like that. In 1999 the tachometer signal is created by the ECU, not by the ignitor like in earlier Accords.

 

Thanks for the response Jim. It has an automatic transmission.

We have some long, high hills around here and it's the sort of thing where the speed limit is 45~50 so you take your foot off the throttle to avoid exceeding the limit.

 

If the check engine light comes on, then there should be a code stored in the engine computer. You can stop by an autozone and have them read any codes stored there. The dealership should have done this too. Post any codes you find on here and we can point you in the right direction.

The other option is that the ignition switch is flaky and is turning the car off momentarily, but not long enough for it to stall. The check engine light would turn on like it does when you normally turn the key to the II position. I think that there is a recall on ignition switches for the 6th gen accords. You should find out if your car is in the recall and find out if you had that switch replaced.

Are maintenance items like spark plugs, dist. cap, rotor, air filter, etc been kept up to date?

 

Thanks PAhonda.

Yes, all of the services and maintainable parts are current. We had the 100k mile service done at the dealer in fall of '08. I don't know if the distributor cap and rotor have been replaced. I could do that.

I'll look into having any codes read; there is an Autozone nearby our house.

 

UPDATE:

I took the Accord over to Autozone where they plugged in their computer to look for any codes. The result was PASSED with no errors.

On a different forum it was suggested that the main relay/fuel pump relay circuit may be bad. I actually found this recommendation for identical symptoms in two other places. So I went to my dealer and bought a:

39400-S84-003 RELAY A 226

for $62 + tax. The parts guy said this is the "main relay" for my car. It is a slide in module about 1.5x2x2" in size, goes behind the dash on the left side. You push up on the old one to get it off the mounting plate.

I've replaced it and will report back here if the problem goes away or not. Since it was very intermittent, I may not know for a couple of weeks.

Thanks to all for your help!

JJ in Denver

 

Hope that fixes it. Normally the main relay problems will cause a non-start, but it's unusual for it to cause a stalling when the car is already running.

 

Follow-up / update: It has been two weeks of daily driving and the problem has not returned. At this point I'm going to assume replacing the relay has corrected the issue. Thanks to all for your responses and support!