OK so I know I have a relay issue.. among others.. but ni can't get it the garage until I replace the relay which controls fuel pump.. ive read the faq sections... where is the relay located?

I recommend you slow down and read more of the threads before changing the main relay. Replacing main relays does not solve most non-start situations on Hondas. You should provide us with more of your symptoms, then we might be able to save you time, money, and frustration.

Your main relay should be located on the left sidewall, near your left knee. Probably to the left of the under-dash fuse box. It will likely be gray, approx. 2" x 1" x 1.5." If you turn your key on and off, you will likely hear it. Normally attached to a bracket with a 10mm hex head bolt. Easiest to remove the lower dash panel for access. It's one thing to take it off, it's often another to remount it. Many have charged down this road for nothing. The solution is in proper diagnosis, not in "plugging and playing."

Ok. I would love some help with this (1998 accord v6 lx)

-3 months ago. Car won't start. Spring temps. Does this once or twice in a month. Starts up after I retry in 15 minutes or so.

-2 months ago. Starting to do it more often. 1 or 2 times a week now

-1 month ago. Car stalls while driving. Won't restart. Wait 10 min. retstarts and I drive home. Now car sits because I am afraid to get stuck. I do some research a realize my fuel pump is not coming on so I swap it out for a new one.. doesn't fix the issue

More research on this site and I start looking under the dash for relays. I do notice that when the key is turned forward and I hear the relay click and the car starts. When I do not hear the relay click it does not start. Also the fuel pump makes no noise when no click is heard.

I checked spark on 3 plugs and all seems OK with that..

New issue.. when the car does start is idles at 2000rpm for about 5 sec then bounces from 1000 to 2000 to 1000 to 2000 over and over..


Any ideas?

My hypothesis is that your Engine Control Module (ECM) or computer is failing, based on the symptoms you described. Honda's Troubleshooting Guide always begins by focusing on the ECM in "Engine Won't Start" situations. They will suggest substituting a known good ECM.

First, is your Accord throwing any Codes? Second, let's run a simple "K Test" on Honda's "key" sensor. It's the MAP sensor, which controls timing (similar to the old vacuum advance on distributors) and air/fuel mixture, depending upon manifold pressure changes. Like any transducer, it converts energy from one form to another. Here, it converts throttle body vacuum pressure changes into fluctuating electrical current signals to the ECM. If this sensor does not receive the proper voltage from the ECM, there will be erratic or catastrophic ignition and fuel system failure. Remember, the ECM is nothing more than a "power transistor," with the job of supplying the proper voltage to a host of sensors (often through relays), under constantly varying conditions. Hence, I believe many main relays that appear not to be working properly are the effect, not the cause. The ECM controls the second relay in the main relay, by applying or removing ground to main relay terminal 8. If there's a developing problem with the ECM, then the second relay will not always work.

With this background information, the second diagnostic step is to test the voltage between the ECM and the MAP sensor. Remove the 3P MAP sensor connector and turn the ignition switch ON. Using a multimeter, check for 5 volts going between the MAP sensor's reference wire(+) and ground(-). When you remove the connector, the reference wire should be the female connector on the right, when you look at the contacts on the connector. It will probably be the YEL/RED or YEL/GRN wire.

This is a simple, state-of-the-art diagnostic technique that I developed to troubleshoot starting and running problems with Hondas. I have been working with [email protected] and he told me he will definitely add it to the Start Problem page. So, run this simple test and we will go from there. All I ask is that you work with me and keep me informed. That's the deal, O.K.

I will definitely keep you informed. I appreciate the guidance. So basically I am just pulling the map sensor harness apart, checking the female side for 5 volts when key is in on position. I assume any ground will do?


As far as throwing codes.. yes.. sorry no numbers just memory.. it is currently reset by my mechanic for diag purposes but as I said I have not been able to drive it

-evap canister is leaking
-2 tranny celenoids have issue
-egr valve issue

I took apart egr and cleaned it out carefully with carb cleaner. Seems to move just fine..

I believe that is it.. I will update asap!

THANKS!

Yes, it's that simple. But make sure you test the reference wire. The ECM grounds to the thermostat housing, but any good ground will work. It would be a good idea to remove this ground, clean it with 600 grit crocus cloth, apply dielectric grease or WD-40, and retighten. This is one of those really important grounds.

Many transmission solenoid issues are due to poor preventive maintenance. I recommend using only synthetic lubricants in your car. They have a higher detergency and a higher coefficient of heat, keeping your engine and transmission much cleaner and cooler. Today's electro-mechanical automatic transmissions are very intolerant of varnish, oxidation, and debris. Change the filter and ATF regularly. I usually use either Mobil 1 or Amsoil, changing engine oil and filter every 6 months or 6,000 miles. If the transmission pan and converter are filled with synthetic ATF, then change it about every 50,000 miles.

The fluctuating idle speed is probably due to poor vacuum connections; e.g. the evaporative canister leak you mentioned, EGR leaks, or leaking MAP sensor hoses.

Strange thing is I got these two changes to idling after poking around under the dash.

-car would start.. run rough and die after 2-3 seconds
-up down idle if it does stay running

Like I said all I did was unplug one blinker relay and plug it back in and the above metioned started to happen

Whether it was just coincidence??

As for the tranny.. yes.. poor maintenance from the previous owner.. I have mobil1 synth in there now but when I pulled the drain plug I had a mountain of metal dust collected on it and a slight burn smell to the old.. never before changed, tranny fluid

I changed it at 80,000... got the car at 70,000

Have you run the "K Test," yet? If you think your automatic transmission is somewhat sludged up, many members of BITOG.com use Auto-RX, which is an ester based product that does a great job of removing engine or transmission varnish, layer by layer, in a very safe manner. Just keep that in mind and check it out, if you're interested.

5.05 volts on the yellow/red wire with the ignition on

Still no start (turns over) or no relay click either when ignition is turned on

Next?

Excellent. At least you probably are not looking at replacing your ECM--they are quite expensive.


Next:

1. Did the MIL come on at all? Did the MIL go off after two seconds?

2. Test all under-hood and under-dash fuses. Turn ignition ON, set DMM to DCV, and test the metal test points on top of each fuse. Don't manually remove each fuse--you run the risk of putting them back in the wrong slot. Fastest way is to disconnect the negative battery terminal, set DMM on audible ohms, and touch each fuse's test points. Tell me the results.

3. Test for spark at the plugs. Disconnect the #1 spark plug wire, attach it to an old plug, touch it to a ground on top of the engine, and have someone else crank the engine. Tell me if you have a solid blue or yellow spark.

4. Test for fuel. Do you hear the fuel pump run, when you turn the ignition ON? If you don't, disconnect the main relay from the main relay connector, jump terminals 5 and 7 on the connector (check in a manual to to verify these are the correct terminals on your vehicle), turn ignition to ON and see if you can hear the fuel pump run. Tell me the results.

What is mil?

I got spark and the fuel pump does not come on as far as I can tell.

I have my ear on the cover and hear nothing when I turn the key forward to on.

So let me try this fuel pump thingy after I confirm fuses... ill get back to you.

Check Engine Light or Malfunction Indication Light (MIL)--same thing.

Did the Check Engine Light come on at all, when you turned the ignition switch ON?
Did the Check Engine Light go off after 2 seconds?

OK here are the results.. looks like the relay?

All fuses OK

Found the box you described to be the main relay

As I was under the dash I had my hand around the relay

It clicked once when key was on but that is it

While key is in on position I tap on the box 3-4 times then I hear another click from it.. voila the car starts normal and runs normal too.

My question is canm this relay cause the engine to vary in RPM like I described?

Also what is your recommendation? Get a new main relay?

Yes, get a new relay. Don't bother with trying to repair them. Varying rpm is likely a separate problem and vacuum related. I hope you enjoyed the methodology we followed and learned some important trouble-shooting skills you can share with others. GOOD JOB! I really enjoyed working with you--very responsive. Keep me posted.

OK cool.. thanks for your help.. although I suspected I really had no idea what I am doing and felt at least a bit more confident with some guidance

So the varying rpm is yet another problem huh? Strange.. well at least I can get it to the garage..

The varying rpm will either go away after you install the new main relay or after repair of the evaporative canister leak. Have you already replaced the EGR valve you serviced?

I want you to replace the new main relay. It's not that difficult, now that you have located it. Go for it--just disconnect the negative battery terminal first. As you press the release tab on the old relay, use a small screwdriver and then a larger screwdriver to separate the connector from the old relay. Snap the new relay on the connector and remount it and you are done.

There is a bolt holding the bracket attached to the relay.. much easier to remove the bolt then remove the relay

I will update on the outcome later today with the new relay but I can't see the relay having anything to do with the fluctuation in rpm

We will see?

Egr was not replaced.. just cleaned and inspected by myself.. could this cause rpm fluctuation?

I agree that replacing the relay probably will not affect the fluctuating RPM. Yes, EGRs can cause big problems in engine performance--I tend to hate them.

OK relay works.. car starts every time.. on to rpm


First time car is started in hours runs normal for about 5-8 seconds (1000rpm)

After this it starts fluctuating from 1750 to 1300 up and down constantly


Any ideas?. I guess the egr would be the next step huh? Unless you have any more diagnostic tricks up your sleeve

Good job. Yes, install the repaired EGR and make sure the MAP sensor hoses are in good shape and not leaking.

No way to test the egr huh? Just got to replace I assume

There might be some vacuum test but I would just check it over and make sure everything looks O.K. Check for any apparent vacuum leaks. Make sure the hose is in good shape. I don't really know your configuration. Only if there is a leak in the diaphragm should there be a need to replace it. You mentioned you cleaned it thoroughly.

Make sure it's not corroded or stuck. Push on the EGR valve diaphragm. Using moderate pressure, you should be able to press the diaphragm up-and-down within the housing. If it doesn't move or moves only with a lot of effort, replace it with a new one.

jaydee23, if the EGR, evaporative canister, and hoses doesn't solve the idling problem, then other possibilities are:

. Bad spark plug wires. Make sure the resistance of each wire is less than 25,000 ohms. Wires that have been taken off and disturbed a lot can cause very unusual idle and running performance.
. Idle Air Control Valve.

Make sure to disconnect the negative battery terminal (or remove the reset fuse) for 15 seconds, in order for the computer to reset itself and relearn everything.

How many miles do you have on your Accord? Have you replaced your spark plugs yet? How would you access the overall condition of the engine?

engine has 80000 and has moderate tune up at 75000.. plugs fluids.. no wires though

there is no rough idling at al.. very smooth.. engine run great and strong

egr seems to be in great shape although I will wait and see if it throws the egr code again.. my best guess is a sensor seeing as though it is so consistently repetative. With a machanical issue my guess is I would get some random ,not perfectly consistent, symptoms.. (unless air leak? )

I really appreciate your help and will look into the suggestion you have made.. my machanics may not be all that happy though.. good honest dudes though..

It is the main relay. A very common problem with Hondas. Word?

Just to chime in... I'm having/had both of the problems you've described on my 98 Accord V6... thanks for the diagnosis and fix for the main relay.

The idle problem was the Idle Air Control valve on mine... just as you described, idle fluctating rhythmically (not erratic) between 1K and 2K rpm. Changed the IAC valve, problem gone...

H20mike, using full-synthetic engine oil and changing the air filter regularly greatly reduces residue/dirt build-up in the IACV, hoses, throttle plate, and plenum.

Sorry to be asking this question again, but I couldn't find the main relay under the dashboard. I have a 98 accord 4 cylinder. The earlier models apparently needed to have the cruise control relay removed in order to get to it, I removed what I thought to be the cruise control relay (silver metal box on the right hand side of the steering column) and I couldn't find it. I also looked around the fuse box but no grey box to be found. Can someone possibly post the position of it on a 4 cylinder?

Thanks.

98accord, it's located to the left of the steering column. Turning the ignition key on and off will help you locate the main relay, by allowing you to hear and feel it "click." Main relays often have 7 wires going to them.

Engine stops and goes I thought it is the gas pump but told I am wrong

I have been chasing same troubles and presently have main relay hanging
Out so next time don't start will measure all points and find out
HOWEVER -as one guy points out all these trouble points go back
To a ground somewhere on the engine and my grounds look corroded
Try cleaning every ground point in the car might clear some grief
Jim
Toronto

Ok. I would love some help with this (1998 accord v6 lx)

-3 months ago. Car won't start. Spring temps. Does this once or twice in a month. Starts up after I retry in 15 minutes or so.

-2 months ago. Starting to do it more often. 1 or 2 times a week now

-1 month ago. Car stalls while driving. Won't restart. Wait 10 min. Retstarts and I drive home. Now car sits because I am afraid to get stuck. I do some research a realize my fuel pump is not coming on so I swap it out for a new one.. Doesn’t fix the issue

More research on this site and I start looking under the dash for relays. I do notice that when the key is turned forward and I hear the relay click and the car starts. When I do not hear the relay click it does not start. Also the fuel pump makes no noise when no click is heard.

I checked spark on 3 plugs and all seems ok with that..

New issue.. When the car does start is idles at 2000rpm for about 5 sec then bounces from 1000 to 2000 to 1000 to 2000 over and over..


Any ideas?

Have been chasing same troubles and presently have main relay hanging
Out so next time don't start will measure all points and find out
HOWEVER -as one guy points out all these trouble points go back
To a ground somewhere on the engine and my grounds look corroded
Try cleaning every ground point in the car might clear some grief
ALSO
I took the main relay innards out only and not the protective box which is
Bolted down it flashed against brake bracket and blew fuse (main
Unswitched feed) and I can't find that fuse anyone know where??
ALSO
After getting brake lines replaced, car would not start in shop and had
To be towed away while in shop I removed battery cable to reset and
Reload computers as mechanic might have hung it up anyone know
How long it takes to reboot a honda
Tnx
Jim
Toronto

Check all under dash and under hood fuses with a test light or multimeter.

Wiz, does the Check Engine Light consistently come on for 2 seconds and then go out, when the ignition switch is turned to ON (Position II)?

Be sure the clean the main ECM ground, which may be located on the thermostat housing. It may have 3 wires going into a brass connector. It goes without saying that all grounds should be corrosion free--clean with abrasive cloth and apply dielectric grease.

The negative battery cable only needs to be disconnected for 10 seconds to clear all codes in the ECM.

Tnx tx
Car wouldn't start briefly today and all voltages were there
In relay except of course to the fuel pump so trouble
Is off in the direction of the grounds
Jim

Wiz, what about the Check Engine Light?

tnx tx
car wouldnt start briefly today and all voltages were there
in relay except of course to the fuel pump so trouble
is off in the direction of the grounds
jim

Tx
Gday
On thermostat are a couple of ugly looking suckers a fat and a thin
In a nice warm and I mean warm place to work is it the thin (only
Three wire maybe or the fat)
Tnx
Jim

tx
gday
on thermostat are a couple of ugly looking suckers a fat and a thin
in a nice warm and i mean warm place to work is it the thin (only
three wire maybe or the fat)
tnx
jim
Gday
A generous spray of oil (wd40) on the ecm ground connector located
At thermostat has seemed to clear the trouble with the ground
That connector requires a tool to undo and should be handled carefully
Jim

I have a 1998 honda accord lx v6 the start with no problem then after getting hot then the engine will cut off. Then when you tried to restart the key display won't show up then after 15 min it will show then the car will start.

It sounds like a nasty vacuum leak in the evap system. Check all of the hoses , even at the canister in the back of the car underneath. There are vac lines there,, one could be off, one or more could be cracked or broken. Have you changed the fuel filter. It could be clogged. You say you don't hear the fuel pump run when you turn the key to on and it appears you have a vacuum leak in the evap system... the vac hoses AND fuel pump wiring are all in the same general physical location... Take a look.