I’ve had my 2000 Honda Accord V6 for about 3 years now and have had an idling issue pretty much since I purchased it. After driving for at least 50+ miles, and if its hot out it can easily have this issue as well, and leaving the car be for around 15 to 30 minutes, on start up the car drops RPMs immediately and dies. Multiple tries and it will do the exact same thing.
Recently I found out a trick to make it work correctly which is revving the engine to 2000RPM for about 3-4 minutes, slowly dropping it down to 1500 RMP for around the same 3-4 minutes and finally down to 1000 RPM for an additional 3-4 minutes and letting off the gas. Usually after doing this the engine idles fine, car drives great.
However, it must be noted that on Summer days with temperatures in the 85+ range, if I’m climbing (going up a hill for a long distance) the car might bog down on me, will not go above 50MPH and I have to pull off the side of the road for 45+ minutes before the car will run correctly again. This has happened about 3 or 4 times in the 3 years I’ve owned the car.
I would rather not have to rev the engine in hopes this fixes the issue each time so I’m wondering what could be the cause in the first place? I’ve replaced so many things including spark plugs, ignition coils, battery, idle air control valve, gasket, fuel pump, fuel pump relay and on. I gas the car up with Chevron gasoline, I’ve dumped in I don’t know how many different fuel injector cleaners and have also tried Heet as well as Sea Foam cleaner. I’ve also had the car checked for vacuum leaks.
I’ve asked multiple mechanics if this could possibly be a vapor lock issue, but they all turn that idea down. They tell me that since the car is fuel injected this can’t be the issue…but, I don’t know, could it be the issue?
If anyone can give me some thoughts or suggestions I am open to them all. Thank you.
My Corolla does that same thing, and I know exactly why it does. I disabled the idle air control function b/c it was broken. That’s the equivalent of the choke system on older cars, and when it is working it increases the idle speed when the engine is cold, just started in other words. Engines have a tough time idling when cold so they idle better if the idle rpm is increased until they warm up. Once the engine warms up the idle air control function returns the idle speed to normal rpm. My Corolla’s idle is too low at first to run well so I have to bump the idle speed a couple times to warm the engine up, otherwise it will stall backing out of the driveway.
On my car the idle air control is a mechanical gadget that works on the same principle as a thermostat. On your car it is almost certainly some kind of electrical gadget. If your car is drive by wire – no mechanical link between the accelerator pedal and the throttle body – then the rpm is controlled by a motor on the throttle body that is controlled by the computer, which decides what the rpm should be based on engine coolant temperature and ambient temperature.
Cars of that era sometimes weren’t drive by wire and instead had a separate idle air control servo motor. So most likely something with all that isn’t working. Sometimes just cleaning the exterior portions of the works with a solvent is all that is needed as that mechanism can gum up over time. Ask your shop if they’ve tried that.
The problem with climbing a hill when it is hot outside and the engine seems to bog may or may not be related. To diagnose that would probably require a fuel pressure measurement and possibly compression measurements. If the check engine light is on, of course that’s the first place to start. Likewise if anything in the routine engine maintenance is not up to date, I"d do that first before spending money on time for diagnosing something that might just be caused because of some maintenance item has been deferred too long…
I think I recall some model year of Hondas have had a recurring problem with the fuel injection system relay or fuel pump relay. Something like that. Usually the symptom is the car won’t start, then if you try later it will. But OP’s symptom could conceivably be related too. OP should ask shop about that, and if that’s a possibility it is probably worth it just to replace that relay. The relay is probably less than $20 and it’s an inexpensive experiment which just might help.
I’ve ordered up an ICM (ignition control module) and will have that installed next week.
So this past Thursday I took my car for a good long ride and it was having the same symptoms. I parked it for an hour, popped the hood and after sitting there for the hour I started it up and it was fine. Maybe the ICM is overheating or is damaged and shorts out when its gets hot.
I’ll report back after the new ICM is installed and I take the car for a ride again to test it out.
Thanks for the replies.
Re: what are the symptoms if my main relay is going bad?
Car won’t start after parked for just a minute.
Car won’t start when hot outside. Fuel injected PGMFI models only
Car starts but quickly dies as the rpm shoots to 1300 rpm.
Once started the car won’t stall.
the symptoms return after shutting off the hot engine
No humming sound from the fuel pump the moment the ignition switches ON.
No click sound after the ignition key turns
10-15 of waiting and the car pushed to a shade will usually start.
I had the main relay replaced last year, I remember this clearly as the same day I ran seafoam through the car. The symptoms persisted of course.
Having read up on the ICM, it shows very similar issues as what the post on the honda-tech site shows for a bad main relay.
And if not the ICM, not sure what to turn to next.
With all the mechanics I’ve talked with about this I guess what they say is true about this issue, could be a number of things that might be causing it.
Well, still having issues. Called up a Honda dealership and they recommend I replace either the camshaft or crankshaft position sensor. Have to do some research on those, talk with mechanics and figure out which it might be. Sure would be nice to be able to test one or the other to find out if one may be the possible cause of the issue. Will see how this all goes.
The bogging and lack of power with a lowered speed on an upgrade would concern me. Something like that usually points to a flaky fuel pump or partially clogged catalytic converter. Since the pump has been replaced that’s weeded out.
A converter could be easily checked with a vacuum gauge.
Some Hondas of this era are under a recall for the ignition switches which can cause intermittent stalling and so on. You might call the Honda dealer and provide the VIN to see if you’re covered on this. If so, it’s a freebie and seeing as how the switch powers the main relay which powers the ECM and the fuel pump…
All good advice… Start in the Tune Up Parts arena… I will never forget being deep in Denial and I dont mean De River over my set of plug wires in my Prelude. It would run perfect then seemingly at random would bog and stutter… I don’t know why i resisted so long but after a cap and rotor and no change…I did the wires…never had a problem again for the 10yrs I owned it.
But it can certainly be the PGM/Fi relay and or the Ignition module…Ignitor as well. The problem lies in there somewhere methinks.