TwistedFish

Hey everyone, this time I've got a new and more interesting problem. Last week, I filled up my gas tank, and (I'm an idiot, i know) accidentally overfilled the engine. The pump clicked, I didn't notice it, put more gas in it, and then it clicked again, and I stopped. I have no idea if this is at all related to the issue, but I also filled it with premium gas, instead of the usual 87 octane. After this, I drove home. After about 4 hours, I needed to get groceries, so i started it up, this time it took a few more seconds and cranks than normal, but eventually it started up, albeit a bit roughly. It sorta felt like the timing was off, and not everything was engaging correctly. Either way, i drove it 2 minutes down the road, and got to a stop sign, where the car stalled. I pushed it back to the side of the road, and waited for a few minutes before trying to start it again. This time, it started up fine, and I was able to cautiously drive it the few minutes to the grocery store. Everything seemed to be fine after that, and i thought "well maybe i overfilled it, and the evap system got clogged, but it seems fine now, so oh well, lesson learned". I was wrong. The next day, After having previously driven to work (and everything seemed fine) it started up a little rough again. Same issues as the first time. I didn't think much of it, and started the drive back home. The car stalled again, this time going about 30 mph. The only similarity with the last time, was that i didn't have the gas pedal depressed. I really only noticed because suddenly i had no power steering. I had to use the ebrake to slow the car down (I was going downhill) and pull over to the side of the road, where again, I was able to wait a few minutes and start it up again (after having it crank without starting for a few times). At this point, I'm getting a little paranoid, because suddenly the car is not starting reliably, and stalls every once and a while. Additionally, (I don't know if its in my head or not) it feels like I'm not accelerating nearly as quickly as before, and now when i put the pedal down all the way, my RPMs scale up, but the car isn't accelerating quickly, and takes longer to shift gears. I'm at a loss here. I'm not a HUGE car guy, but i would certainly like to know what to do so I can learn and fix it myself. If any of you have any advice, it would be greatly appreciated. Thank you!

TL;DR: Car stalls and has trouble starting sometimes, feels like it accelerates slower. Please help.

Edit: Sorry for the typo in the title, I can't figure out how to change it.

JvG

I'd say that you over filled the gas tank. Excess gasoline might have entered the charcoal canister and the engine is flooding.

You might want to let the car run at idle for a while till the excess gas or fumes evaporates from the charcoal canister.

Our cars were built to run best with premium fuel.
That's not the reason the car acts as it does.

TwistedFish

I'd agree, except for the fact that it was around 4 days ago, and I've been driving the car pretty consistently... I guess I would have figured that excess gas would have been "burned off" by now. An interesting tidbit: (which may have nothing to do with anything) when i go to fill up the tank, the tank gauge needle takes about 5 or 6 minutes to move all the way up to full... is that normal?

JvG

I'd say that you still have too much gas in there.

You might want to remove the gas cap and then let the car idle.

The excess gas has no where to go as it expands right now. Except into the engine.

It's likely that the slow rise on the gas guage is directly related to the tank being too full.

TwistedFish

That's fair, the only issue is that sometimes (when it's hot outside for example) the car randomly wont start. The only new thing is the stalling, really. So I'm sorta lost here. Thanks for your reply!

JvG

The gasoline in the tank would expand the most when it's hot outside. Normally it would expand into some empty space at the top of the tank.

You have over filled the tank. So the only place for it to go is into the charcoal canister and associated plumbing. The valves and plumbing would try to purge what should be gas fumes into the engine.
Only it's dealing with liquid gasoline. The gas mixture is probably rich as flock. That would result in an engine which does not run right or perhaps stalls. The reason I recommended removin the gas filler is that the gas fume's need to vent. Put the cap on loosely so that fumes can vent, but not much gas can slosh out. Expect that the check engine light will come on. It would react to the open gas cap. The engineers would have anticipated someone doing what you have done. I'm going to guess that there will be no long term damage.

I'm just a diy guy who has maintained and repaired his own cars since 1971. I have read a lot, but have no formal training.

TwistedFish

Okay, that makes sense. The thing is, sometimes the car wont start when it's hot, even when I'm not on a full tank. Either way, on a mechanical level would there be something in need of fixing that would cause this? Maybe I need a new fuel filter or something? For now, I'll do what you suggested, and I'm sure it'll work. But for the future, if it's hot outside and the car won't start (immediately) even on half a tank of gas, would should I do to stop that problem?

JvG

Please make sure that the gas cap is just on loosely. We want excess fumes to escape.
We also want to let air into the tank so that it won't develop a vacuum as the fuel pump sucks liquid gas out. A vacuum in the tank leads to stalling.
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TwistedFish

So to be clear, you think the fix to stop the car from taking a good while to start up in hot weather, even without a full tank, is to just keep the gas cap on loosely?

The Wizard

iTrader: (43)

IMO, you didn't really overfill your gas tank. If you would have, it would have spilled out right then and there and run down the side of the car. Your issue has absolutely nothing to do with how you filled up that day.

The fact that your car won't start when it's hot tells me that it's your Engine Coolant Temperature Sensor (ECTS).
Stalling is generally caused by vacuum leaks (rotted out hoses), a bad MAF, or a bad ECTS.

I fixed your thread title. Good description btw.

TwistedFish

Okay, thanks for you input! I probably should have added above, I do also have a code reading that my knock sensor isn’t working, although I don’t have CEL. Would that help to narrow anything down?

The Wizard

iTrader: (43)

The knock sensor would clearly explain the loss of power that you described. A bad KS does not affect starting. Is that your only code?
A bad KS doesn't always trip a CEL. Clear it and and see if it returns.

TwistedFish

Yes, that's my only code. I'll clear the code when i get home!

JvG

He did not have these problems until he over filled the tank. But he did right afterwards .

I find it difficult to believe that an outside cause such as an ects suddenly went bad the same day.

The Wizard

iTrader: (43)

Like you, I like to retrace steps to figure out the cause of things. In this case though, I believe it's just coincidence. You're making it sound like gas it going places that it shouldn't be. When you overfill a gas tank, the gas comes out the fill nozzle. I don't believe the OP overfilled his gas tank at all. He said, "The pump clicked, I didn't notice it, put more gas in it, and then it clicked again, and I stopped." This is completely normal. When the handle clicks, I too squeeze it again until it clicks a second time to be sure. No harm, no foul. No overfilling done. Had he truly overfilled his tank, it would have come out the fill nozzle and ran down the side of the car.

The Wizard

iTrader: (43)

I would also like to add that it's practically impossible to overfill your gas tank; that's the whole point of the gas pump nozzle "clicking" and shutting off. Either the nozzle would have to be defective and not click off, or one would have to pull back the gizmo on the nozzle and pull back the nozzle slightly in the car gas filler hole to even pump more gas.

JvG

One way to confirm Wizards theory would be to leave the gas cap on loosely. The car would continue to stall out once it reaches operating temperature. Yet the gas tank would be able to vent to the atmosphere. And since it could vent, my theory would be proven incorrect.

I experiment in order to test which course of action is best.

Wizards theory is as good as mine. I respect his opinion. He is probably the most experienced member we have.

TwistedFish

These are all interesting points. After a few more days, I've noticed a couple of things. 1: My tank is now down to about 3/4 full, and I haven't stalled once in 2 days. And 2: I'm still having times where i try to start the car and it cranks for longer than normal. It was hotter than normal today (I live in hawaii, so it happens quite often) and experienced this a few times. My theories: Maybe I need to clean the throttle body? Maybe I need a new fuel filter? Interesting tidbit: When i turn the key to "on" I never hear my fuel pump. Are the maxima's fuel pumps in-line?

CS_AR

The latest post make me think about the ECTS. I've seen this happen when the engine is warm and the ECTS not-sending a signal to the ECU adjust fuel for a warm engine. This is usually noticed at convenience stores and gas stations when the engine is turned off for a short period of time and restarted. The engine is warm but the ECU thinks it is cold and sends more fuel than required causing a mild flooding condition.

How to test an Engine Coolant Temp Sensor video below.

JvG

Could be the ects.

if over filling is the root cause, it's possible that there is still excess gas in the charcoal canister and such. That would vaporize and cause an over rich starting situation. It would take some time for the fumes and liquid gas to be burned off.

if things get better with time, my theory was correct. If not, Wizards ects theory is correct.

I

TwistedFish

This seems like a pretty good idea... I recently replaced the radiator (the old one was leaking) could this be the cause?

TwistedFish

Also, I just remembered a perhaps important point: When I bought the car 3 months ago and since then (until the most recent fill up) I’ve always used (and I imagine the previous owner did as well) 87 octane gas. Only with the most recent fill up did I use 93, and only after that have problems started.

My question is, since the Knock sensor will “retard” the engine timing when using 87 octane gas (or so I’ve heard) and I have a KS code (P0325), could this be at all related? I think I’m just grasping for straws at this point, because I thought it was fine (the last few days I haven’t stalled) but today after parking in the hot sun for a few hours, it stalled again. Also interesting but completely irrelevant, I may need a new neutral safety switch, because for some reason the car wouldn’t crank in park today, but would in neutral.

Thank you guys for your replies, keep em coming! I wanna get this figured out haha.

JvG

Sometimes switches can be affected by temperature when they are at the point of failure .
You might find that replacing that switch might solve other issues.

Regarding the knock sensor . Timing will be retarded if the sensor is bad. It won't benefit from premium gas. But using premium won't cause damage.

You will definitely notice increased performance once you replace a bad knock sensor and also use premium gas.

I suggest taking care of other items before you tackle the knock sensor. It is possible to replace the knock sensor without removing the intake manifold. If you do remove the intake manifold, keep in mind that there are other important maintainence items which you might as well take care of at the same time. You will save a lot of time and aggrivation by removing the intake manifold instead of several times .

TwistedFish

Yeah, and since it stalled again today (the gas is a little above half a tank) I went ahead and bought a replacement ects, so we'll see how that goes. Getting to it is kind of a ***** though, you have to take all the air intake hosing and crap off

slickblack94

iTrader: (5)

I think its the MAF.... buy a cheap one, and let er rip tater chip

TwistedFish

New Development! Not really a good one either... I was going to replace the ects, but when I removed the “power cable”? To it, it sort of just crumbled into pieces. The ects LOOKS fine, but I still haven’t replaced it.


Ects looks okay, no terrible corrosion, but the power line housing is destroyed

What’s my next step here? I don’t even know how I’d go about replacing this...

Rit

iTrader: (3)

How are your soldering skills ? I would try to pick up a replacement connector from a junk yard, and heat up the old solder iron !

JvG

The sensor can look fine, but still won't function properly.

Regarding the connection. Find one at a wrecking yard. Remove the old one. Solder the wires.

The Wizard

iTrader: (43)

I don't see any broken/exposed wires. Only the plastic housing is disintegrating. May want to consider adding some liquid electrical "tape", then wrap with some black electrical tape and call it a day.

TwistedFish

Okay, a little over a week now, I've replaced the ECTS, and the gas has gone down (I refilled it only halfway with 87 octane).

It doesn't stall anymore (thankfully, though i still don't know the original cause). Unfortunately, it still has rough start ups from time to time (and times where it cranks for a while before starting, these are one in the same, meaning that it only has a rough start up before going back to a normal idle after i have these long "crank sessions" lol) most often in hot weather. Last night, it was only about 68 degrees, not hot at all, the car had been parked for hours at this point, and it still had a very hard time getting started. Today, after parking in the hot sun, it also takes a while to start. It seems the problem isn't ONLY in hot weather, but exasperated by the hot weather. I'm at a loss here. Maybe its the fuel pump? I never hear it hum when in the "on" position... maybe its busted? I have absolutely NO idea whats going on. Please send help lol. Thanks for all your previous and future advice.

JvG

Do you have codes?

Have you tried putting the gas cap on loosely like I suggested?

Please confirm that the car ran just fine, and no codes before you over filled the gas tank.

Zerodrag

iTrader: (1)

Consistent hard starts, I figure could be the ECTS (which you have addressed).
Random hard starts could possibly be cam position sensor. Since it is easy to access, you could try checking to see if it is fouled with oil. It is also a relatively inexpensive part if it is found to be bad. I am unsure if a failing one throws a code, but mine did not when I had that issue and replaced it.

TwistedFish

Hey, so i have one code, the knock sensor (P0325 I believe), however I don't think that has anything to do with the problem. I did put the gas cap on loosely, and even before overfilling the tank, it had the hard startups, it just didnt stall.

TwistedFish

I haven't actually looked into this at all... could this be something that would be amplified in hot "ambient" temps? Also, as stated above somewhere (I don't blame you for not reading the whole post, theres a ton of comments lol) I don't have any codes except P0325 for the knock sensor.

JvG

Does the exhaust smell like unburned gasoline.

Do you have white exhaust fumes.

Has your mpg gone down noticalbly recently.

TwistedFish

No, nothing like that has happened yet. The only bad smell i get from the car is the smell of burning coolant, but thats because i had a radiator leak before (which i fixed, by replacing the radiator) and now i think its just residual coolant thats burning off. IPlus, i don't seem to be losing any coolant. And I dont feel like my MPG has gone down at all, in fact when this all started, with the premium (92/93 octane) gas, i was getting better mpg than before.

JvG

I use premium due to mileage and performance reasons.

My questions are related to one of the more common hard starting reasons our cars can have.

We are experiencing an epidemic of leaking fuel injectors.

A leaking injector will cause low fuel pressure at startup. Followed by the white exhaust. Also stinky exhaust fumes.

It's difficult diagnosing what's wrong when no codes are present. So we try the process of elimination.

one more test for possible fuel leakage.

Please disconnect the vacuum line from the fuel pressure regulator. Then sniff it. Does it smell like raw gas.

TwistedFish

I'll start on that tomorrow! Thanks for the advice!

Zerodrag

iTrader: (1)

Mine would randomly have hard starts when it was warm. Another possibility on hard starts when warm, and the car has been sitting for a bit, is a leaking fuel pressure regulator. That's pretty easy to test as was mentioned on the above post i believe.

JvG

Zerodrag,

Yes, I was thinking that a ruptured diaphragm in the fpr would cause loss of pressure, or flooding conditions. The presence of gas or fumes in the vacuum line would be an indication.

I want to eliminate fuel leakage as the cause of his problems . So I'm thinking fpr and injector leakage could be a cause. But possibly not after the tests.

Feel free to disagree. Thanks.

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