Hi,

I'm no mechanic but I like to do my own work on cars, partly on costs and I like to see how things work. I'll try to summarize my issue and focus on the important details as much as possible. My gf accidentally put in diesel into the tank a few weeks ago and I was able to drain and clean the fuel system as best as I could by searching on fitfreak and other sources on how to go about it. My issue now is even if I can get the car to run it wont stay running longer than a few seconds. Before I was able to get the car to start by using starter fluid and it would idle perfectly. Then the more I used the starter fluid the rougher the idle became until It wouldn't start at all even with the starter fluid. I'm assuming it has something to do with the ecm/pcm or sensors telling the ecm/pcm to shut down as a failsafe. I've bought a new battery 151r, adjusted valves, changed fuel pump, changed relay, but nothing helps. Any advice is greatly appreciated. Im trying to avoid taking it to the shop. Thanks in advance

 

First, have you completely removed all traces of diesel from the tank, lines, rail and injectors? (if not, that's a problem by itself)

Assuming fuel system has been cleaned thoroughly and is ok, I'd next suspect the cat has been clogged with soot.....Remove the primary O2 (AF) sensor from the pipe and see if that allows it to start and idle (probably won't do much above idle but it will be a clue you're dealing with clogged exhaust).

If it ran that way..... Then disconnect the first exhaust pipe from the header (manifold) and see if it can run with full power and reach rev limit RPM..

 

How do the spark plugs look?
If they are black clean or replace them (use cheap ND plugs with copper electrode just o see if engine starts. In worst case
Diesel fuel may add soot and carbon deposits on the back of intake and exhaust valves.
Starter fluid is an excellent solvent so it possibley flushed these deposits and brought them to the valve seat. (Saw similar situation with 92 Miata)
To rule this out, do compression test
Also it might be a good idea to swap fuel injectors
A word of caution: diesel fuel residue and soot in the exhaust is creating fire hazard.

 

Spark plugs are ok. A lil black but i cleaned all the soot and grime off and looks ok. I dont think im having an issue with spark cause when i use starter fluid or shoot fuel where the injector go the car will start just fine. But right after it starts if i wait a min or two the car just slowly dies out. Then when i try to start again it wont start or if i manage to get a combustion it would die shortly afterwards. I think the other advice might have something to do it. Like the o2 sensor or one of the sensor is telling the ecu/pcm to shut off. I believe that because when i tried reseting the ecu/pcm im able to start the car using starter fluid again and set the idle. Then when i turn the engine off it wont start even with the starter fluid. I'll try taking the o2 sensor off on my next attempt to see if that do any improvement and touch base after. Im kinda tired of working on the car but stubborn and let the shop have all the glory. Does anyone have a diy link or step by step instructions on how to remove the o2 sensor? Please and thank you. You guys have provided me with loads of info and great troubleshooting data. Its awesome knowing someone has your back for all us diy-ers. Thank you all!!!

 

You will need a 7/8" tool for oxygen sensor removal.

If you can get a 7/8" open end wrench on it, great. Unscrew that sucker.
If not, you'll need a more specialized tool for sensors such as one of these.....
If you don't want to buy it, you probably can rent one from DangerZone and the like

 

based on symptoms the diesel fuel has clogged the fuel line near injectors take fuel rail out and inspect injectors. Older injectors (up to 1997) used to have tiny filter on its inlet (not sure if Fit injectors have one). These filters can be gently pulled from injectors and washed in fuel treatment or mineral spirit.

 

I'm just going to go through what I've had to do on cars with this problem.. You've likely done all this but ... WTH..

You'll probably need to disconnect the fuel line for the fuel rail and clamp a hose on it, then jumper the fuel pump relay and let the fuel run in to a can until its clean, you probably also need to swap out the fuel filter, and maybe the fuel pickup strainer and possibly send the injectors to a shop for cleaning and service. I would empty the tank with the fuel pump and then dump in 2 gallons of the lowest octane fuel you have locally because if you don't pull the tank to clean it its likely to have almost a gallon of fuel still in there.. repeat pumping till it stops. Now put 5 gallons of clean 87 in it, jumper the pump again till you get fuel without air coming out(Less than 5 seconds.. ), reconnect the line to the fuel rail and install your nice clean injectors.

You probably washed the cylinder walls clean of oil using too much starting fluid.
(All you need for starting a car with ether is a shop rag, squirt a bit of the ether on it and hold it by the intake pipe, if it needs more than that you have a fuel delivery problem.

Remove the plugs and shoot a 1/2 teaspoon of motor oil in each cylinder and crank a couple times to spread it in the cylinder then replace the plugs..

Now your ready to try starting it. BUT first,,, check every single fuse in the fuse box to make sure none are blown.. There are interesting interactions between electrical circuits in new cars and a fuse that has nothing to do with your problem can cause your problem.

It should crank up and run within 30 seconds or so,, any more and you have another problem.

Engines don't run because of either: No spark or No fuel 90% of the time..
Once you foul plugs on these new engines you need new ones.. The iridium plug is really sensitive to fouling once done its almost always game over for them. Cleaning often doesn't help in my experience, it might get you fired up but its a coin toss.

Usually an O2 will throw a code, but I've never seen one cause a car not to run at all..

Good luck!

 

Hey Dwtaylorpdx and others,

Thank you for taking the time to explain what to do cause thats exactly the process i did except of motor oil i put a 1/2 tsp of gas before i started using the starter fluid. I just didnt know how explain it well enough so people would understand. Then when i tried starting it sure enough it would start for 10-15 seconds then die on it own or when i tried pressing down the gas pedal. Then when i would try starting it again i would just get the crank no start issue. Or if i got the combustion needed it would bog or studder really bad for a couple sec then shut off. Is it possible one of the sensor is telling the ecm/ecu to shut off so it wouldnt ruin the engine? Cause if i could get it to start and idle it would only be a one time deal unless i took the neg off the battery and put it back on after a few mins. I got it to start a couple times using the starter fluid and idling smoothly a few time and i let it run for like 15-20 min (reving to 3000-4000 rpm thinking it'll clean the line and injector more) then i would shut it off hoping it would start on its own since it was running just fine but tried to start it again and i would only get crank no start most of the time. But if it did start it would die shortly after no matter what. I tried pressing down on the gas pedal to give it more juice but it wouldnt even rev up. Im at a loss on what to do next. Might just let the pros deal with it. I havent yet cause everyone been giving me hope that i can do this on my own. Thanks everyone!!

 

So you've had it running on the fuel in the gas tank, that's good. 3000-4000 RPM would indicate the exhaust isn't restricted enough to kill the engine.



What methods did you use to drain the diesel from the gas tank? Did you dump in some gas and try to run it? How much? Did you drain the tank again and refill with gas again?
In detail please.....I'm trying to figure out if there's still a significant percentage of diesel-gasoline mix in the tank now, because diesel doesn't burn clean in a gas engine at all.



Pull out a couple spark plugs and see if they are black with soot.
Wet, or dry?
Post pics?

 

Yes, ok in details. whenever i can get it to start it can stay running with the fuel i currently have in there. I siphoned most of the diesel but seeing as the tool could not reach where the last bit of diesel was i'd say i left about a gallon give or take. Not thinking ahead i added around 6 gal of gas 89 octane cause my friend told me i needed higher octane so it would mix with the diesel and make it easier to start due to diesel was oil based (hindsight:what i should have done was kept turning the car to the on position until all the diesel was out of the fuel line and then add the new fuel but since i couldnt locate the fuel line quick release i followed his suggestion) Then i tried starting it a lot by turning the key to the on position about 10-15 times before i turn the key all the way over and it would sputter or just crank over but no cumbustion. So i figured needs spark. Took out the spark plugs and the ends look black and grimey so with a micro fiber cloth i gave it a quick rub downn until it wasnt so blackened and place them back in and got same results. So a housemate and fitfreak member told me to try adding a lil bit of fuel to where the injectors would be and start the car to see if it would even start. I followed his instructions and when i turn the key to the ingintion it would start no problem and smoothly for about 10-15 sec then sputter and die out. Now i knew the spark plugs wasnt the problem since it was able to ignite the fuel and since it couldnt stay on it must be the pump, fuel, injectors or fuse/relay out. Checked fuses and relays all seem in working condition. Replaced fuel pump cause thought diesel might have ruined or clogged the old pump. Placed everything in and with the fuel line connector off near the firewall i turn the key to on and fuel would flow out for a couple seconds. Connected the fuel connect and tried to start her up but no luck. So moved to next part, the injectors.

So i removed the injectors and cleaned them out. Boy, that was a pita cause i couldnt hold the injector and supply power and spray injector cleaner at the same time but did the best i could. At first it wouldnt spray but once i got it going it would spray out a good flow and then flipped it and did the process again making sure it sprayed out both ways and one more normally. Placed same amount of fuel where injectors would sit and installed injectors n fuel line. Then started the car and it would start easliy and smooth then idles kinda rough and the sputter and die. So figured didnt do a good job cause i took the rail off but with the injectors still attached i asked someone to start the car and fuel with spit out but not smoothly and so repeated injector cleaning steps but this time built a small box to hold the injector while i sprayed the cleaner through and and supply power with ease of a button. Then just to confirm the rail was clear of diesel i placed the injectors on the rail and sprayed the cleaner through and it would spray smooth and evenly. Placed everything back on and did same steps as before and it would start but now it idled for awhile so i thought it must be a miricle that i was able to get it running.

Celebrating too early thinking everything would work normally now i step on the gas pedal and the engine shuts off or dies. Turn the key to the start position again and this time it starts normally but when i step on the gas pedal the needle with move up slightly then decrease along with my hopes of fixing this car. So now im thinking the timing or valves. Performed a valve adjustment by following instructions from a different post and didnt seem too difficult. Especially since i can get the parts off pretty quickly now. Car would start and idle fine but everytime i step on pedal it shuts off so figured sensor is telling it to shut off or the computer went bad in all the process.

At my wits end and tired of doing the same procedure expecting different results (def. of insanity i know...) i go to the local oriely to purchase a new batttery (the old one was buldgy and after cranking it a few times the starter would whine slower) and maybe their reps might have more insight on what it could be. They were no help at all. Couldnt even give me any advice or insight at all besides take it to the shop. Decided they were of no use and stood in line to pay when i spot starter fluid on the rack next too me. Remember watching a friend use it to start his car i decided to copy his methods. Got home Installed the new battery 151r but still no luck. Figuring i'd give up and let the shop have a go now i glance over to see the starter fluid canister sitting there i think to myself "why not? Its going to the shop either way and cant hurt." So i spray it into the air intake and it started up. thinking its going to die after all the fumes are exhausted i sit there waiting for it to sputter and die but a few mins pass by and it was still going strong idling quietly and smooth. My interest rekindle and hopes high i step on the gas pedal and it stays on and revs to 2500-3000 easily. Glory within my grasp i rev higher and still it keeps running. Remembered reading how to do the idle reset i perform that process but wasnt sure i did it correctly cause when i reved it to 3000 for five mins it wiould just rev louder but never reseted but wasnt sure since it was my first. Turned car off and started it up again but this time its idling rough so turn the key off. Tried turning it on again but no go. Not even with the starter fluid. It would sometime start then die within secs or not at all. Resetted the ecu the next day and it would start with the aid of starter fluid. Drove it around the block a couple times to relearn idle. Stopped the car and when i try to start it up just cranks. Used starter fluid and it starts for a couple seconds but doesnt idle or if it decides to idle its for two sec then sputters and dies (like a bad soap opera death scene). Then it wont start with or without the starter fluid. Checked the spark plugs and tips are blackened and wet but not gunky like before. Wiped them down and placed it in again. I hope this help resolve any questions on the process i took. I would like to get any input on what it could be. Sorry its so long. Thanks for taking the time to help or read this. I'll post pics and a vid of my issue when i get the chance.

 

I've been without a car for about a month n a half now and it sucks big time...

 

So you probably have (roughly) a 20% mix of gasoline and diesel. This is probably your entire problem. Diesel can't burn well in a gas engine, and you haven't got it diluted enough to run reliably. (even if you get it to run decent, even a small amount of diesel mixed in can cause problems, so it's important to get it cleaned out or diluted out as much as possible)

If you are using the electric fuel pump in the tank to drain the tank, it will leave approximately a gallon of liquid in the bottom.

Dump that mix out, FLUSH it out by repeating the process a few times. You will have to empty the tank, add some gas, empty the tank again, add some gas, empty the tank again. Repeat until the fuel coming out doesn't smell like diesel....because unless you wish to pull out the tank to clean it, the best you're gonna be able to do is dilute the diesel until it's mixed weak enough to not cause huge problems.


Cheap gas is fine, no point in using higher octane.

There is no Schrader on Hondas fuel systems, you have to disconnect the fuel supply line to drain the tank (by running the fuel pump) and purge the fuel system....probably in the engine compartment would be easiest.....



The lines and injector rail probably hold enough fuel for the engine to run or the car to drive a mile before fuel from the tank reaches the rail and injectors. The fuel system is "returnless" so anything the pump picks up and sends into the fuel line and injector rail has to exit through the fuel injectors.

Sounds like you just ran down the battery from all the cranking, without getting the engine to run enough to recharge the battery. Probably could have just purchased a battery charger as the battery was likely still good.
They sell parts, not fix cars. If they could actually fix cars they probably wouldn't be pimping parts.

Same goes for asking technical advice from a tow truck driver.

In our shop you would have been billed for an appropriate amount of labor time and some fresh gasoline, and if we weren't totally swamped you probably could have had the car back by 5PM the same day LOL.

 

For best results perhaps the gas tank may have to come out off the car and fuel pump should be removed for complete draining of the mix. Diesel is heavier than gas so it tend to collect at the bottom of the tank around fuel pump well.

 

Diesel and gasoline should mix together easily though, they are both petroleum products.
Simply pouring one into the other will mix them together pretty well.
Shake the car side to side if you wish.

It's certainly not like trying to mix water and gas.



That said, when I have to do this type of job at work I will go with whichever way I feel is a good combination of most effective and fast. One car might get the pump yanked out and the car tilted to one side so all fluid can be extracted by a vacuum pump, another might get the tank yanked out so it can be cleaned on the bench.
The last Fit I received with a tank of diesel got the tank removed for cleaning.

Water contamination in a fuel system requires more work, water will sit in low spots and collect in the fuel rail to cause problems and stray misfires later.

 

This is what I've found:
Putting Diesel into Gasoline

Now, let's look at the reverse – you’re mixing a higher flash, heavier fuel into a base fuel (gasoline) that’s lighter, more volatile and burns at a much lower flash temperature. Despite these differences, putting diesel into gasoline won’t cause nearly as many problems as the reverse.

The biggest concern is the reduction in octane. Thinking about how gasoline burns in an engine, octane rating is the measurement of gasoline’s ability to ignite at the right time – not too early. Gasoline with lower octane rating will ignite too quickly once it is injected into the chamber. The gasoline ignite and explodes, but the piston is still on its way up and the resulting pressure wave collision gives you (at best) a knocking sound and (at worst) damage to the piston and rod. In a sense, octane slows down combustion, it delays it.

Gasoline needs to have an octane rating of 87-91 to fit today’s car engines. Diesel fuel has an octane rating of 25-40. Mixing 2% diesel fuel into gasoline will lower the overall octane rating by 1 point. Getting 10% diesel contamination lowers octane by 5 points, which is enough to create problems in most engines. The octane depression rises linearly with increasing percentages of diesel fuel in the gasoline.

So higher levels of diesel contamination will damage the engine and give you blown pistons and cracked heads. More moderate diesel contamination will give you dirty combustion and can damage the engine over time if something isn’t done.--end of the quote
BTW, in vintage (read 1950 to 1970) 2 stroke engines (that used 1 to 20 oil in gas mix ratio) oil tend to sink to the bottom of the tank, requiring agitation of the fuel tank before starting the engine. Diesel/gas mix may (but not necessary) act similar way

 

Awesome, thanks for all the data and help everyone. Going to drain all the gas from the tank and purge the line. I'll keep you posted on the matter

 

I helped a friend with this problem after they towed their honda to my house, full tank of diesel. The Lseries have a "quick connect" fuel line right under the throttle body. Disconnected, attached a hose, and filled up a few 3 gallon pails with the mix by cycling the key on at first, but then wiring the pump to "on". When the flow started to sputter, siphoned in ~4 gallons of premium and a splash of seafoam. Started the car on starter fluid and it ran a little oddly for the tank, and after a fresh tank of premium it shows no issues and is back on regular running fine.

 

Hi guys,

Latest update: ok, i can sense im close to having the car run as it should. I flushed the tank out and put 5 gal. Of fresh new gas. It still wont start without the assistance of the starter fluid (or i started just placing a gasoline drenched rag in front on the air intake) but it'll stay running rather than spitter and die. Then i performed the idle reprogram. My rpm seems to idle a lil below 1000 rpm but its stable but i notice a faint clicking noise. After i did the reprogram it died. I pop the hood and with my gasoline rag repeated the steps to start it and it started again where as before it wouldnt. So i decide to take it around the block for a test as i am cruising down the street i fell the gears shift and once it shifts the throttle would depress or even if i pressed on the gas pedal it wouldnt accelerate then it would misfire. Im assuming when i did the vavle adjustment i must have tightened them too tight thus the misfire. So i pull over and tomorrow i'll perform another valve adjustment. In the next run if i cant get it to run properly i'll have no other choice but to leave it to the pros. I just hope it wont cost me an arm and a leg especially since i've done most of the work already.

*If i did everything correctly otherwise that would be another issue for the pros to fix.

Thanks to everyone who read and posted advice. I appreciate all the help and knowledge everyone provided. Really boosted my confidence and auto knowledge. Thanks all!!

 

Sounds like dumping the gas tank again and more fresh gasoline would be in order.

Remember: If you are only using the electric fuel pump to empty the tank, there's always about a gallon of liquid left in the bottom when the pump is done.....so you probably still have a bit of diesel in the current mixture.

 

Understood. The first time i siphoned the diesel out it left about a gal. as you guys said and I was unsure of draining the leftover so I just mixed the remainder with 6 gal. of premium. This time around I didn't to leave anything in the tank to rule it out so I siphoned all i could with my tool and then got a rag and soaked the inside of the tank and then wrung it out into a pail until there was nothing left besides the shiny reflection of where it once inhabited. Replaced the fuel pump module and then dumped a fresh new 5 gal of 87 grade octane thru the filler neck.