Hi, I would appreciate any thoughts or advice you all may have on this Check Engine Light issue. I got water in my gas tank about a year ago (and unfortunately ran it through the engine). I had the engine cleaned out, but afterwards it would still idle a little rough from time to time, and the check engine light would come on. Autozone told me the codes indicated cylinder misfires. I added some HEET and that fixed it right up and the check engine light went off.

What seems weird, at least to me, is that whenever I fill up the gas tank and don't add HEET, it'll start to idle rough again. If I do add it, it's fine. This has been the pattern for the past year. Could there still be water within a closed system in the engine that's not burning off? Again, any ideas on causes or fixes would be much appreciated.

Thanks!

 

Welcome new member, but WHAT YEAR Accord, 1977??

Since about 2003 they have a non-return fuel system, so there's less large-scale mixing in the tank. How much water? Maybe some left in the bottom of the tank somewhere? But a year sounds way too long. Many years there's a drain plug in the tank. Maybe you should drain it?

Could be you fouled the plugs & that's giving you occasional problems. Try new plugs? Use NGK because Honda seems to get along best on them.

 

Thanks for the response! It's actually a 1999. It was LOTS of water. My tank was about 1/4 full, and I went to an Exxon station and pumped a mixture that was probably 80% water, 20% gas. They did own up to it and paid to have the tank drained and for repairs, but I've had this annoying residual effect. (I'm assuming the two are related, since my current problem started just after). I'm with you, I figured any leftover water wouldnt have lingered this long.

I was thinking the plugs as well. I checked them out before and they seemed fine, but it might be worth replacing them. I appreciate the info.

 

Got paperwork for that repair? Maybe what should have been done is not only drain the tank, but remove the fuel pump & clean the inlet screen?

By 1999 there isn't a real fuel filter. Just a fine mesh bag/screen around the pump inlet. It's not a routine replacement on any kind of schedule, but it seems like this problem should have caused them to replace it.

There's maybe as much as a pint of gasoline circulating thru the pump, supply line, fuel rail, FPR, & return. That much water could have circulated back to the tank, unless they flushed that too. It would be good to have a list of what was done.

Think it was just water? Maybe some mud in there too?

 

first of all, welcome...
fuel system is not a circuit, so there's no way anything from the pump up could have returned to the tank...
have your fuel pump taken out(it's o the trunk under the mat towards the back seat. (i have the 00'.
it's really easy to take out, then run it on gas to it cleans itself, do the same to the injectors... there should be no water what so ever...
let me think a bit and i'll get back at you...

 

Fuel supply pipe goes to the engine compartment, flows into the fuel rail.
FPR throttles the return line to control pressure in the rail.
Fuel flows through FPR, into return line & back to tank.
Sounds like a circulating system to me...

Beginning in 2003 it's non-return, but all that means is the FPR & return are all contained within the fuel tank.