3genube

ISSUE BEGINS HERE: My car (92 maxima GXE) was stalling very badly when I put it in drive but it seemed to idle ok in park.

So, I changed spark plugs, spark plug wires, distributor cap, rotor and fuel filter with OEM parts. This didn't fix the problem. Car still stalling badly. Tried Chevron fuel injector cleaner in gas tank, but it didn't make any difference

Next I checked the injectors. Four of the injectors were not reading between the recommended 10-14 ohms (1,3,2,6). So, I changed these injectors. But after I completed the job I noticed that car was leaking raw fuel from the tailpipe and was still stalling badly. Opened up the car again and checked/changed o-rings with OEM o-rings based on reading various discussions on after-market o-rings. Verified with fuel rail lifted and switch to ON position that the fuel injectors didnt leak. The 4 injectors I replaced are all new (not remanufactured) Beck-Arnley. Injector resistances: #1 (10.9ohms), #3 (11.4ohm), #5(11.8 ohm), #2 (11.0 ohm), #4 (12.0 ohm), #6 (11.8 ohm)

So, I thought all good. I drained/changed the oil and put in new oil to get rid of the gas-laden oil. But when I start the car it still leaks raw fuel from the tail pipe. I am afraid to run the car for too long or even to warm up the car, as I am worried it may hyrdolock.

Here are some diagnostics I have performed:

- tested spark plugs good using inline spark tester (have good spark)
- Injectors seem to all be getting pulses from the ECU (tested all with noid light)
- Disconnected each injector one at a time - still leaks gas
- Disconnected injector 1, 3 - Car starts on first crank, still leaking gas, still idling ok. Doesn't seem to make a difference if I disconnect these two injectors
- Disconnected injector 1,3 and 2 - car starts after couple of cranks, still leaking gas, but idling ok, i.e. still does not stall badly.
- Disconnected injector 1, 3, 2 and 6 (4 and 5 connected) - car needs multiple cranks to start, still leaking gas, car still idling, almost stalling but not completely dying
- Disconnected injector 1, 3, 2 and 4 (5 and 6 connected) - car needs multiple cranks to start, still leaking gas, car still idling but almost stalling and then dies
- Disconnected injector 1, 3, 2 and 5 (4 and 6 connected) only - car needs multiple cranks to start, still leaking gas, car still idling but stalling and almost dies

I dont see any gas in the Fuel Pressure Regulator Vacuum hose which connects to manifold. So not sure if this is a Fuel Pressure regulator issue or not

I took out the spark plugs and see # 1 smells of some gas but it is not wet. Spark plugs 3, 2 seem to be little black but no smell of gas.

My guess is there may be an issue with one or more cylinders 1, 3 and 2 but still unclear what is causing the gas to come out of the tailpipe.

Is there anything I can do without opening up the car again to understand the cause of the gas coming from tailpipe ?

NOTE: I guess next steps would be to check fuel pressure, compression etc. I dont have these test instruments. I have already spent a lot of money on parts, tools and test instruments

NOTE I have not let the car warm up, as I am worried about hydrolocking it. So, I am not sure if this gas is due to gas collected in the catalytic converter from my previous injector change attempt. How much gas can collect in the catalytic converter ? It is consistently spitting out fuel, so it does not appear to be any remnant fuel that remained in the catalytic converter

Thank you for any tips or advice.

chrome91

iTrader: (1)

is your oil level way overfull? because if youre getting fuel out of the tailpipe, some fuel should be leaking past your cylinder rings and mixing in with the oil in the oilpan

are you for sure getting spark on EVERY cylinder? if not, thats where the excess unburnt fuel is coming from. if you are 100% getting spark on every cylinder, i can only guess maybe the fuel pressure regulator is causing something or the PCM is commanding the injectors on too long. just too many variables

DennisMik

iTrader: (2)

For gas to come out the tail pipe, it has to go through the cylinders in order to get into the exhaust system. There isn't any other path. With all that you have done, you have somehow missed the source of the problem.

It is possible, but highly unlikely, that a fuel injector is stuck in the open position. I don't know how you could test that without a specialized tester.

Otherwise, the more common possibility is the o-rings. And while you said that you have replaced them, maybe you are working under Murphy's Law and damaged one again. Did you replace the o-rings for the 2 injectors that you did not replace?

You need to try to narrow the problem down to a specific cylinder. while the engine is idling, pull one spark plug wire and see if the idle changes. If it gets worse, then that cylinder is OK. No change means there is a problem. Do this for all the cylinders.

The part where you had the fuel rail lifted and looking for leaks is not a valid test because unless the engine is running, the ECU shuts off the fuel pump. You would have to jumper 12 volts to the fuel pump.

The resistance of the injector coils don't matter for a problem like this. High resistance means the fuel injector won't open up. But kudos on your thorough troubleshooting.

James92SE

iTrader: (31)

Initial thought would be an injector stuck "open", although very unlikely now with completely brand new injectors.

Second thought would be FPR issues. You've changed so much other crap, you might consider changing it now too (about $50 right now on Rock Auto) just for good measure.

When you turn your key to "on" and the fuel pump primes, does it shut off after the 5 seconds or whatever?

Last year I had a head gasket fail on my Civic which filled one of my cylinders completely full of coolant, so much so it hydrolocked the engine. Thankfully I could "feel" it and didn't keep trying to start the engine and bend a rod or anything.

Anyway, I fixed it, and it was flinging coolant straight out of the exhaust for probably a good 30 minutes run time after I first started it up. I was getting worried that my head gasket repair job was a failure but it turns out all that crap was just stuck in the exhaust system.

If I were you, I'd pull your cat and start it up and see if you're spraying any fuel out from the y-pipe. That would be your quickest way to tell if fuel is just stuck in the exhaust system or if the engine is still spraying fuel. You could also then check to see if your cat has a bunch pooled in there.

Gas evaporates pretty quickly so you wouldn't think it could pool in there for long. Although if it's trapped between the engine and cat it's effectively "sealed" in there and perhaps wouldn't want to evaporate.

James92SE

iTrader: (31)

Ahh you know what, I didn't even notice you only replaced four injectors. I sort of skimmed/assumed that you replaced the whole set. One of the injectors you didn't replace may very well be stuck "open".

Like Dennis said, you need to figure out which cylinder it is. Surely you've got a nice pool of gas sitting in one of the cylinders.

3genube

Hi all, thanks very much for your replies and tips. I will post back more observations once I try out these suggestions.

Tiniform

Or there could be an exhaust valve not closing for whatever reason. An open injector seems more likely though.

ac max 92

iTrader: (13)

My bets on either one or more of the injectors you replaced aren't seated properly in the fuel rail or one or more of the o rings.

3genube

The rationale for disconnecting the harness to each injector was to isolate which injector was dumping fuel. I assume not getting a signal will disable the injector from injecting fuel into the cylinder. Is this correct ?

When I disconnected 1, 2 and 3 the car didnt stall. But when I disconnected either of 4, 5 or 6, there was a noticeable difference.

This makes me believe the issue may be with cylinder 1,2 or 3

What is odd is that the fuel continued to run out of the tailpipe even though 1, 2 and 3 injectors were disconnected.

ac max 92

iTrader: (13)

Are you sure your not refering to 2,4 and 6 and 1,3 and 5 which are the back 3. The harness that runs the injectors 2,4 and 6 on the front is a plug and play sub harness which ive found to be the most problematic for misfires due to wiggling the wires but for your fuel out the tailpipe either an injector is stuck open or not seated properly in the rail allowing fuel to dump into the cylinder. You need to test the resistance on all of your injectors to ensure they're all between 10-14 ohm if they are you need to take the intake off and find out which injector(s) isn't seated properly in the rail or has a bad pintle cap or o ring.

3genube

Hi ac max 92, I pulled each spark plug as suggested by several of you, and I and see that the misfire is on cylinder #1. It is the one on the back closest to the passenger side. I put in a q-tip into the cylinder and it was wet with fuel when I pulled it out.

#1 is one of the injectors I had replaced The injector resistance is 10.9 ohms. So, electrically I suppose it is good. I checked the other cylinders and didn't find any fuel in the cylinders nor a misfire. #2 seemed to have a slight misfire. This is another one where I had replaced the injector. But I didnt find any fuel in cylinder #2

Now it looks liek I have to take it apart a third time. Is there any easy way for me to check for a pinched o-ring/leak before I close it up? The last time, I had tried the procedure of turning the ignition key to ON and verified that none of the injectors leaked gas. It did seem to pressurise the fuel rail.

But given that the issue is still there, as chrome91 indicated, it may not be a valid test.

The fuel pump seems to be ok per question from James. When I turn the key to on, I can hear it whir and then it stops after 3-4 seconds. So, I assume this is working correctly and not on all the time.

I am going to start taking the plenum apart again

Some things still not clear to me:
1. Do I need to siphon off the fuel from cylinder #1. How do I get it out ?
2. How can I determine whether the leak is from an open injector, o-ring not seated properly or pintle cap. I dont want to close it up and find out again that there is still a leak.

Thanks for any other tips.

jakeru

What kind of replacement injectors are you using?

I've had problems like you describe with aftermarket injectors. Replaced them all with a set of good used OEM injectors (and scraped all the corrosion off the connectors, and reassembled with dielectric grease and weatherproofed the degraded/cracked rubber connector boots) and injector problems have forever since been a thing of the past.

3genube

I used the Beck and Arnley new injectors not the remanufactured ones.

ac max 92

iTrader: (13)

The beck arnleys should be fine. To help answer your questions you would know if the injector was stuck open when you tested the resistance. 10.9 ohm is good and within spec. When you take the plenem (intake) off if i remember right i believe it's just four bolts to pull the fuel rail. Check the plastic pintle caps on the tips of the injectors to see if their are any cracked or broken. As for the o rings there really is no easy way you have to remove the injector. When your putting the injector in try putting a little lube on the o rings to help you put them in a little easier without damaging the o rings and try not to force them in in an awkward way gently twisting clockwise and counter clockwise should be o.k and make the tops of the injectors are flush on the rail and don't appear crooked or slightly lopsided in any way and make sure when you put the bracket with the 2 small screws back on over the injector make sure the little spacer is there under it and not missing and that the bracket is tightened down well. You could always cross reference with another injector that you haven't replaced and isn't leaking. As previously stated it is a good time to just do all 6. As for your fuel in the cylinder it will eventually evaporate or what you could also do to help remove the eccess fuel is pull the fuel pump fuse so the pump doesn't prime and crank the engine a couple times breifly then replace the fuse and see if it turns over but before doing any of that pull the plugs in the flooded cylinders let them dry up and put them back in. Hope this helps you out a little and makes sense lol.

3genube

Much appreciated ac max 92. Am going to try this over the weekend and post back.

ac max 92

iTrader: (13)

Another little piece of advice is there should be a coloured dot on the side of the injector. Try and keep all your injectors consistent with the same colour to ensure a proper flow pattern. As long as ALL of your injectors test between 10-14 ohm and you don't have any damaged pintle caps or o rings and the injectors are seasted properly in the fuel rail you shouldn't have any issues. Also while your in there check the small pieces of fuel tubing on either side of the fuel rail and make sure there is no cracks and that they are in good condition. If they've never been changed and for what the fuel tubing is worth at your local parts store by the foot you could always replace them while your in there but that's up to you.

CMax03

iTrader: (3)

Hope you didn't hydraulically lock your engine....

3genube

Thanks. I havent started working on it yet due to heavy rains here. I dont recall seeing a dot on the aftermarket (beck and arnley) injectors. I will check. I will also check the tubing. Its a good point.

3genube

I didnt have any problems starting the car. I did not drive it other than run it for about 5 min to locate the misfiring cylinder. So hopefully it is not hydraulically locked.

ac max 92

iTrader: (13)

Hopefully theres no damage to the cat aswell. If you only started it to find a mis and your not driving it you should be fine.

Maxpwer

iTrader: (7)

I strongly suspect (like James said) you have an excess of fuel in your exhaust that will take time to clear out. You may fix your issues but still have gas coming out the tailpipe for sometime after, leaving you to believe that it hasn't been fixed.
I have 3 steps guaranteed to find your issue.
First, pull the intake and fuel rail. Get a bucket just wide enough that you can rest your rails on top (or rig one up with something across to hold it up) so all the injectors will spray into the bucket (make sure to remove/disable anything related to the ignition system). You can the turn the key to the on (not start) position so the fuel pump will pressurize the rail. You will quickly see if you have fuel leaking past an o-ring or an injector stuck open. If so, repair and test again. If you have a leak past the o-ring, pull the injector out and get new o-rings in case one is damaged (I know they were new but you can pinch and/or cut them during install). Make sure you lube them up generously with oil as well as the inside of the rail (I prefer and recommend synthetic since I've never had an issue, but I have no real proof its any better than regular oil since I've never tried it)
Step 2, disconnect the exhaust somewhere between the block and the cat. If you can remove the y-pipe completely this would be ideal as you could pour out any gas trapped (and upgrade to an aftermarket Y-pipe at the same time). With an open exhaust you can run the engine and see if gas is actually still coming out. If not, and you stalling has cleared up, you probably have a bat/clogged cat. Try a shop vac or leaf blower to speed up evaporation of the rest of the gas. Once dry, if you car still stalls with the exhaust hooked up you know you cat needs to be replaced. If you still have gas coming out the open exhaust, then on to...
Step 3, with the exhaust still open you need to compression test your engine. You either have skipped a tooth or two on the timing belt causing the exhaust valve to open too soon or close too late. This will be verified by low compression numbers (but similar) on all cylinders. Replace the belt, making sure you timing is correct and test again. If you only have one or two low compression cylinders, you may have a bent or seized exhaust valve. It's possible you have a bad head gasket but regardless, if you've done all the above and still has gas in the exhaust, it's time to pull the head and find out what's up.

3genube

Thanks all for your feedback. It is much appreciated

It has been raining here, but I got a small window of opportunity to try the procedure in Step 1. Here is a video I made. I put ziplock bags under each injector. Put back fuel pump fuse, reconnected battery and turned ignition to ON. I did find that injector 1 was spraying fuel from the bottom. Other ziplocks were dry. So, this is the only one leaking. This was also verified to some extent earlier on when I tried pulling each spark plug to locate the misfire and I had found fuel in cylinder 1.

This is my third attempt at injector replacement Last two times it was spraying from both top and bottom. So probably I am not putting the injector in correctly. So, I tried removing the injector. During this process somehow the middle enclosure with the net did not come out with the injector. It remained stuck inside. So I had to pull it out separately. It is the last photo in the video. I have to get a new injector now. I will hopefully get it in this week and replace it. Will post back. Hopefully this was the issue and I wont need to do step 2 and 3. Fingers crossed.

Short video clip. Injector shown is #1. You can hear the fuel stream as soon as I turn the key to ON position and stops when I turn the key back to OFF. Next photo is the fuel collected in the ziplock. I assume this is what is causing the fuel to get into the tailpipe. Final photo is the injector after I pulled it out. I used 3 thin flat screw drivers about 120 degrees apart to press/lift the injector out from the top side. I was gentle enough but still when I removed the injector, the plastic enclosure around the body of the injector (with the net) remained stuck inside the hole. I had to pull it out separately. Pintle cap is fine, o-ring doesnt appear to be pinched or torn.

londonflu

I had the same symptoms last year; problem was solved by replacing an injector and O2 sensor.

DanNY

iTrader: (14)

just to rule out the connector...did you try and plug the connector in another injector to see if it does the same thing?

3genube

No I didnt try that. I didnt know you could do that. But I tried the noid light on all connectors and it seemed to be pulsing ok. Not sure if this test the same thing you are asking

3genube

I wasnt able to work on the car for a couple of weeks. Just got to it today. I put a new injector on cylinder 1. I greased the o-ring and the inside walls of the injector receptacle with grease and the injector went in smoothly. I pressurized the rail and didnt see any drips. So, closed everything back up and started the car. Starts on the first try i.e dont need to crank multiple times. But still smoking and smoke smell like gas but it not dripping gas. It could be the residual gas but not sure how long it would take to clear out of the exhaust. I ran the car for at least 10 min until warm and drove the car forwards and backwards and still has the smoke. I pulled spark plug on cylinder 1 and dont see any gas in the cylinder anymore. So, I guess I am at step 2 of what MaxPwer suggested. It will take me some time to figure how to take the exhaust out. Never gone under the car before except to drain oil. If there are any tutorials, pictures of what this looks like it would be a big help. Also, the car does not stall. It starts every time, runs smooth and does not stall, except for the white smoke from the exhaust which smells like gas. I also checked the codes and codes read 55 in mode 3, ie no trouble codes. I havent tried to drive it much as I am worried about hydrolocking the car. I have to do more checking tomorrow. If any other suggestions, I will try them. Thanks much

londonflu

Now change your O2 sensor, and you should be golden! Advance has with NTK ones, made by NGK.

londonflu

Here's what happened to mine last year:

Problem:

Thought I'd make a late night/early morning run to the store today, then on the way back about 1 block from my place, I started getting a hesitation and loss of power, so I turned off everything since I just had the 2nd alternator replaced again just last week (first one was defective), thinking it was related, turned off headlights, stereo to see if it was a power draining issue. Still hesitated pulled into my parking spot and turned the ignition off. waited a minute or two and then tried to restart, it took two cranks before it finally started. It hasn't been 5k miles since I did the injectors, knock sensor, coil packs. It was dark out so didn't bother to pop the hood but I did notice white smoke coming from tail pipe smells like fuel. First thing I though of is me cat must've went out?

Solution:

Replaced leaking fuel injector & O2 sensor.

ac max 92

iTrader: (13)

Good to hear you got that injector seated properly. Listen to the tailpipe and if it doesn't sound like you have a misfire and the throttle is smooth with no stumbling or hesitation then i'd just take it for good runs on the highway to burn off any residual raw fuel. I wouldn't bother taking the pipe apart just yet. The raw fuel has probably damaged the cat and has or will burn up the substrate in the cat especially if it's an aftermarket and not oem. I'd just wait until closer to etest time and take the pipe apart one time to change the cat and possibly the o2. If it fails emissions with high hydrocarbons then chances are the cat is probably no good.

3genube

Thanks londonflu and ac max. I am going to try these things and post back