Need EXPERT help with a problem car at work. 2000 Honda Accord V6.

[DJ Hellfire]

*This is very long, but it has all the info for you guys to possibly help me out with this.

This 2000 Accord V6 has me stumped at work. The car comes in on a flat bed as a no start. So I do the diagnosis and figure out that the car has a weak fuel pump and bad gas. Put a new fuel pump in, disconnected the fuel line before the pressure regulator, put a hose on the line, and powered the fuel pump manually from a jump pack and pumped all the gas through the hose into two buckets until no more came out. Was about a half tank of this crap. Took a sample in a clean drinking glass and there was about 85-90% water with a small amount of gas on top. It was obvious that someone blatantly put water in this tank.

Went to Exxon and got $10 gas. Poured a little in another drinking glass to compare to the bad crap. That bad crap was piss yellow with merky *** water and piss yellow gas floating on top. The new stuff was nice and clear. Pour the rest of the $10 in the tank with a bottle of dry gas. Car starts up fine and runs smooth after a few cranks. But here is where the story takes an f'ed up twist.

Road test the thing and whomp on it. Stalls out on me about 1/2 a mile down the road and I left my cell phone home that day. Push it into an Outback Steakhouse parking lot. Cranked it for a while with no luck. So I just sat there for about 20 minutes, tried again, and it started right up. Take a u-turn. Get a little ways back and it stalls again. This time it wouldn't start back up. So we towed it back. As soon as we got back to the shop and got the car off the truck, it starts up fine.

So this time I beat it around the parking lot and could not get it to stall. As soon as I am about to pull it back in the shop, it stalls. This time, I decided to take a fuel sample again. It was slightly dirty/yellowish, but didn't have the fuel on top of water anymore. Just wasn't as clear as the new stuff. Put the line back on, cranked it, and it started right up.

So by this time I have come to a realization. Whenever it stalls and wont start back up, all I have to do is crack the fuel line and relieve fuel pressure and it will start up. So this morning I come in and let it run until it stalls. Try to crank it right away and it will not start. So I immediately crakc the fuel line to relieve pressure and it starts right up. I found that this trick works everytime it stalls. So I figured there must still me a bit of moisture or water in there. So this time, I take the car to exxon and fill it up with premium. On my way back it stalled and would start. I called one of the guys from my job to bring me a 14mm wrench. Relieved fuel pressure and what happens? It starts and I drive it back to the shop.

So for some reason, when this thing stalls, it will only start by relieving fuel pressure first. I didn't check fuel pressure because you need a special Honda tool that I don't have. But trust me, it has plenty pressure. Too much pressure you ask? I doubt it. The reason being is that if you spray carb cleaner in the intake and crank it, it will run only as long as you spray the carb cleaner. So if it was flooding itself, I would think spraying carb cleaner would just flood it more and not let it start. It will only run on it's own after relieving fuel pressure.

Any ideas? Also, it has 1 code, but I doubt it's related. It's for vehicle speed sensor and auxillary inputs.

[2001VE]

I'm no expert but I'll give my 2 cents. First guess would be fuel return line to the tank could be plugged up. Try blowing it out with compressed air. You haven't mentioned changing the fuel filter , also probably a good idea. Not knowing fuel pressure makes it harder to trouble shoot. With vacuum hose off fuel regulator I believe pressure should go up a few psi. Maybe test it without vacuum , bad regulator can sometimes do weird things. But there would probably be a code.

[DJ Hellfire]

I'm no expert but I'll give my 2 cents. First guess would be fuel return line to the tank could be plugged up. Try blowing it out with compressed air. You haven't mentioned changing the fuel filter , also probably a good idea. Not knowing fuel pressure makes it harder to trouble shoot. With vacuum hose off fuel regulator I believe pressure should go up a few psi. Maybe test it without vacuum , bad regulator can sometimes do weird things. But there would probably be a code.


As for the fuel filter, I didn't bother replacing it because 1.) the pump didn't include a new one and 2.) it's just one of those white bean bag type of fuel filters that snaps onto the bottom of the pump. So fuel goes through the bean bag to the pump and then directly to the regulator. No way for the filter to really clog since it's not paper, plus pressure seems adequate.

Also, I was thinking about a faulty regulator, maybe rusty inside. But the car is not loosing fuel pressure (because you need to relieve pressure to restart the car after stalling) and it's not excessive pressure (because when it stalls, it will run off carb cleaner but not the tank fuel).

I wonder if maybe there is a rail or injector problem.

[BobMs_wht2k2]

On our 99/00 TL's (Accord with a 3.2) we had a bulletin for an updated PCM/regulator for hard starts. I would guess that mixing age, neglect and bad gas could havethe same effect.

[Cypher]

When it stalls out are there any other symptoms? you said relieving fuel pressure helps it to start. Is there black smoke or anything that would indicate excessive pressure right when it stalls?

Have you tried hooking up a modius scanner and driving around and seeing if watching any of the values helps you?

This sounds about as weird of a problem as a WRX we had in that wouldn't start when you put gas in it.

[reallyflycouple]

I'm a 12 year Honda Vetran, I'd order the adapter from Honda and confirm your fuel pressure readings first. Make sure your return line is breathing freely to the tank. I know you need to lower your rear sub frame and tank to change your pump. Maybe you crossed a line with a evap line or pinched the return on assembly somehow. Another thing you can examine is your long and short term fuel trim values. They are a great way to see how lean or rich it's running. A faulty fuel pressure regulator won't make that engine stall. That would only make it run rough, lack power or fuel economy. You could have a failing injector due to water saturation. If the injector is staying a fuel duty cycle and stalling or not starting, relieving the fuel pressure would help the car start as well as allowing the injector to function again...only a theory though. You really need to see your fuel psi.

[DJ Hellfire]

When it stalls out are there any other symptoms? you said relieving fuel pressure helps it to start. Is there black smoke or anything that would indicate excessive pressure right when it stalls?

Have you tried hooking up a modius scanner and driving around and seeing if watching any of the values helps you?




When the car is running, it has great power, no smoke, or anything. It runs like it should. Didn't connect the modus while driving it.



1. I'm a 12 year Honda Vetran, I'd order the adapter from Honda and confirm your fuel pressure readings first.

2. Make sure your return line is breathing freely to the tank. I know you need to lower your rear sub frame and tank to change your pump. Maybe you crossed a line with a evap line or pinched the return on assembly somehow.

3.Another thing you can examine is your long and short term fuel trim values. They are a great way to see how lean or rich it's running. A faulty fuel pressure regulator won't make that engine stall. That would only make it run rough, lack power or fuel economy. You could have a failing injector due to water saturation.

4. If the injector is staying a fuel duty cycle and stalling or not starting, relieving the fuel pressure would help the car start as well as allowing the injector to function again...only a theory though. You really need to see your fuel psi.

1. Yeah, I didn't know where to get the adapter from. I tried to rig something on where the damper thing goes next to the regulator, but it leaked no matter what I did. I can just go to Honda a get the adapter?

2. Acutally, there is an access plate in the trunk (4 door, not coupe) that lets you get the pump/sending unit out right through the trunk. So I didn't have to drop the tank. The lines and pump assembly only fit back one way, so there was no way to cross them. But it is a good idea to check the return line. Maybe the return line is clogged and backing pressure up on the engine side? Would explain why fuel pressure relief would start the car.

3. I didn't get a chance to get a scanner on it. I only have a code reader and our shop foreman is the only tech authorized to use the Modus.

4. I think the injectors are a great possibility as well. But you have to take the manifold off to check that, and the customer barely wanted to pay for the diag and needed repairs. So I didn't really wanna start ripping apart the engine to check **** that I won't get paid for doing.

[reallyflycouple]

I've only had to drop the tank twice on these....never because of pump issues. Only because of mice eating the EVAP lines on top of the tank. I've never looked specifically for a access panel. I thought you still couldn't remove the pump from there. I thought there was only enough room to disconnect your lines. I always say you learn something new everyday.

[DJ Hellfire]

I've only had to drop the tank twice on these....never because of pump issues. Only because of mice eating the EVAP lines on top of the tank. I've never looked specifically for a access panel. I thought you still couldn't remove the pump from there. I thought there was only enough room to disconnect your lines. I always say you learn something new everyday.

I believe only the sedan has the access in the trunk. One of the guys I work with had to replace a leaky tank on a coupe a few weeks ago and he said there was no access through the trunk. He had to lower the subframe and tank before he could disconnect the plug and lines. Lucky I had the sedan. Took me only 30 minutes to do the pump.

[cclngthr]

Sounds like a bad regulator and/or return line (if it has one), injector issue. Change the filter (always do that), check the PSI to the injectors and see if it is within normal range. I had a few Honduhs that did this on me and it turned out that the regulator and injectors were weak (although that may not be it 100% of the time).

[OneandOnly1]

So, was this ever resolved?