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Start and then Stall -- '04 EX-L 4wd

1686 Views 77 Replies 10 Participants Last post by  undivide
This happened after the spouse returned from grocery shopping with a mixed highway + local driving: the car struggled to start, and after it started, it stalled immediately. There was some notable vibration from the engine bay before it stalled. For the first 2 tries, it left a strong gasoline odor. After a 3rd start, I pumped gas for a min or so and the car got into the normal working state. Once in this state, everything worked fine and I drove the car on the road without issue. It even stopped at STOP signs and traffic lights without stalling or abnormal vibration.


[Update 1]: After turning on/off a few times, the symptom is now repeatable: if right foot rests on brake, the car cranks strong but it won’t start; if/when cranking the car and at the same time pumping gas (ie right foot not on brake pedal), the car can start -- is the foot not on brake a sign that something went bad? Once started and pumped gas for a few seconds, the car drives just fine – it doesn’t stall in subsequent stops at STOP signs or at red lights.

[Update 2]: When the hard-to-start-then-stall occurred, there was no CEL or any warning light on the instrument panel initially. After many on/off tries, now the engine light and VTM-4 light are on.

Vehicle repair history: it’s a 2004 EX-L, 4WD with 203K miles:
- Starter and alternator are still original
- spark plugs were replaced with NGK at 152K miles in 2017
- EGR valve was replaced in 2017 at 155K miles
- timing belt and water pump n all belts are replaced at 157K miles in 2017
- diff fluid changed in 2019 at 172K
- 2 O2 sensors (the ‘04 EXL only has 2 O2 sensors) were replaced in 2018 at 164K miles
- valve adjustment done & PCV replaced in 2021 at 189K mile
- The battery was replaced in Nov, 2022 and is practically new

I searched and the past working fixes include: valve adjustment; fixing timing belt jump one tooth. Neither seems the cause of the problem I am experience.

Where do I look next?
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Damn Felpro! For all fellow piloteers: if you adjust valve lash, do yourself a favor and get the OEM valve cover gasket!
It is well known that Felpro sucks and should not be used, again as you said, only use genuine Honda valve cover gaskets, price is not to be a concern here (and it's not like they cost an arm and a leg anyway). And valve cover gasket replacement may be necessary at other times other than valve adjustment = leaking.
 

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Turn A/C on to see if it makes a diff, as ECM should adjust idle higher when A/C is on.

Another possibility is engine temp sensor, would be nice if you can watch live data and see what ECM sees for various sensor data if you have a scan tool.
 

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you replaced the valve cover outermost gasket but did you do the press fit tube seals at the same time?
if not, don't blame felpro. I went with a beck/arnley kit and no leaks anywhere. just clean the oil out of the tube before reinstalling the plug.
also those covers require a special torque sequence to properly seal it down.
everything in the factory service manual
 

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Discussion Starter · #46 ·
you replaced the valve cover outermost gasket but did you do the press fit tube seals at the same time?
if not, don't blame felpro. I went with a beck/arnley kit and no leaks anywhere. just clean the oil out of the tube before reinstalling the plug.
also those covers require a special torque sequence to properly seal it down.
everything in the factory service manual
Did I press fit tube seals? yes, I used a large socket and gently pressed it. I did get 14K miles since the valve adjustment. Could my craftsmanship be improved? Probably. After all, it was the first and probably last time I do a valve lash adjustment.

Anyhow, I made some progress today and replaced the #4 tube seal with a Honda OEM one today. The old seal was ripped in the middle. No wonder oil leaked. I managed to remove the front cover for cyl#4 5 6 without removing the intake manifold because there is plenty of space to move the cover out once the 5x 10mm bolts are removed. This probably saved me a good 2-3 hours.


" just clean the oil out of the tube before reinstalling the plug." --> I used a piece of paper towel to clean up the oil. There must be still oil left in the plug well since the engine bay had a puff of smoke shortly after the car started & warmed up. Smoke did not re-occur though, so I am reasonably sure that left-over oil is burnt up.

Good news: the CEL disappeared, and the car is drivable.
Bad news: the car was still shaky after a warm start, as if it will stall. This is observed after idle relearning (I disconnected the battery when replacing the tube seal).

Another sign that something is not working as expected: when gear is at "P" and after a warm start without pumping gas, RPM jumps to ~1500 momentarily and then it settles at ~700-800. What gives the momentary RPM surge?

P.S. 1. the attached pic is the old #4 tube seal after the cover is removed.
2. a 10mm socket was dropped in the car and nowhere to be found. A cost that was not budgeted.
 

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The surge is Idle Air Control Valve. The shaking is likely related. Remove the Throttle body and clean it really well. Do not move the Butterfly Valve. I would say clean it without removing the Throttle Body, but I bet the gasket is bad. Replace with a new one, and make sure to get the old off. Do not scratch the aluminum surface. You can use a plastic razer blade sold at Walmart. Make sure to dry it before re-installing it. If you don't the liquid-carbon created from cleaning will dry and cause the butterfly valve to stick, or could settle at the bottom of the butterfly valve and cause it to restrict airflow.
Razer blades
 

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This happened after the spouse returned from grocery shopping with a mixed highway + local driving: the car struggled to start, and after it started, it stalled immediately. There was some notable vibration from the engine bay before it stalled. For the first 2 tries, it left a strong gasoline odor. After a 3rd start, I pumped gas for a min or so and the car got into the normal working state. Once in this state, everything worked fine and I drove the car on the road without issue. It even stopped at STOP signs and traffic lights without stalling or abnormal vibration.


[Update 1]: After turning on/off a few times, the symptom is now repeatable: if right foot rests on brake, the car cranks strong but it won’t start; if/when cranking the car and at the same time pumping gas (ie right foot not on brake pedal), the car can start -- is the foot not on brake a sign that something went bad? Once started and pumped gas for a few seconds, the car drives just fine – it doesn’t stall in subsequent stops at STOP signs or at red lights.

[Update 2]: When the hard-to-start-then-stall occurred, there was no CEL or any warning light on the instrument panel initially. After many on/off tries, now the engine light and VTM-4 light are on.

Vehicle repair history: it’s a 2004 EX-L, 4WD with 203K miles:
  • Starter and alternator are still original
  • spark plugs were replaced with NGK at 152K miles in 2017
  • EGR valve was replaced in 2017 at 155K miles
  • timing belt and water pump n all belts are replaced at 157K miles in 2017
- diff fluid changed in 2019 at 172K
- 2 O2 sensors (the ‘04 EXL only has 2 O2 sensors) were replaced in 2018 at 164K miles
- valve adjustment done & PCV replaced in 2021 at 189K mile
- The battery was replaced in Nov, 2022 and is practically new

I searched and the past working fixes include: valve adjustment; fixing timing belt jump one tooth. Neither seems the cause of the problem I am experience.

Where do I look next?


Howdy,
I just had a similar issue with my wife's 2004 Pilot. It was very intermittent, but long story short, I believe you need to replace the main relay, under the dash, near the steering column. I spent the extra and bought the Honda, O.E. part.
I also remember, when the green security light would light up, it would start up normally. If it didn't light up, it would crank, but not start. At one point, the vehicle would crank and not start.
I would tap the relay; the light would then come on and I then knew it was going to start.

Good luck, I hope this helps,
K-Lap

P.S.
You mentioned at one point, when it was acting up, you could smell fuel, so that eliminates the fuel pump and other fuel delivery items...
 

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Discussion Starter · #49 ·
Howdy,
I just had a similar issue with my wife's 2004 Pilot. It was very intermittent, but long story short, I believe you need to replace the main relay, under the dash, near the steering column. I spent the extra and bought the Honda, O.E. part.
I also remember, when the green security light would light up, it would start up normally. If it didn't light up, it would crank, but not start. At one point, the vehicle would crank and not start.
I would tap the relay; the light would then come on and I then knew it was going to start.

Good luck, I hope this helps,
K-Lap

P.S.
You mentioned at one point, when it was acting up, you could smell fuel, so that eliminates the fuel pump and other fuel delivery items...

In my case I never experienced the green security key not showing up. Thanks for your input though.
 

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Discussion Starter · #50 ·
The surge is Idle Air Control Valve. The shaking is likely related. Remove the Throttle body and clean it really well. Do not move the Butterfly Valve. I would say clean it without removing the Throttle Body, but I bet the gasket is bad. Replace with a new one, and make sure to get the old off. Do not scratch the aluminum surface. You can use a plastic razer blade sold at Walmart. Make sure to dry it before re-installing it. If you don't the liquid-carbon created from cleaning will dry and cause the butterfly valve to stick, or could settle at the bottom of the butterfly valve and cause it to restrict airflow.
Razer blades
I am tackling IAC valve. I got to the point where throttle body is detached and I cleaned it thoroughly.

I am stuck at removing the second Philip screw that fastens the IAC to the throttle body. It's rusted and the screw head is stripped. I cut a deep groove with a hacksaw and hoped I could use a flat screwdriver to loosen it, but it doesn't budge so far.
 

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Discussion Starter · #53 ·
If you have a quality vice grip, you can get on the screw head from the side and twist it off. If you made a good cut on the screw head you can also use plyers or something similar on the flathead to help twist the screwdriver giving you more leverage.
Yeah, after cutting a deep groove, and used the flat head screwdriver, it didn't budge: the screw is rusted and it's really tight, even after I soaked it w/ WD-40 overnight. It's probably not a good idea to continue in this route as there were shredded metal pieces from twisting. If the metal on the screw head is broken into pieces, it will be really a long day.

I tried a vise grip today and no success yet. The screw head is round and the grip is not firm enough to break it loose. Also there is not enough space to find a good angle to grip. I will give a few more tries, and if I cannot break it loose, I will take it to a shop.
 

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There are two different types of impact drivers. Both have flathead bits. The hammer style that you hit can even take a socket depending on the style. The electric impact driver would work as well.
 

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WD40 is a great spray lubricant but you really want to use PB Blaster (y)
It's ability to penetrate down into threads is unmatched! Definitely take the throttle body to a shop if you have doubts about further damaging anything. I think worse case scenario you can order new/rebuilt or salvage yard throttle body.
car-part.com is a great resource
though me personally I would probably get the rebuilt from cardone even though its an extra 80 to 100 dollars because they've already done the cleaning for you with brand new sensors.
 

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Discussion Starter · #60 · (Edited)
@royalbiggster I really appreciate your tips. With the flathead bit + impact driver, I managed to break it loose and the IAC valve was taken off the throttle body. I replaced it with Standard Motor AC229 -- it's sold by Amazon and made in USA, and I hope that it works as well as the OEM one.

In addition to this, I checked coils and spark plugs for all 6 cylinders: #1 and #4 are soaked with oil. I replaced the #4 cyl plug seal a couple of days ago and today did #1. The end result is that the car does not stall any more, and the check engine light disappeared after driving for about 30 mins. That is good.

What's annoying is that at warm idle, it still has noticeable vibrations from the engine bay. Note that all these are after performing the idle learning procedure. It seems that there is something extra/else that is not working properly, or will vibrations disappear after driving it for some time? The car drives fine without vibration at both local and highway speed.

I will leave the lesson here again: do NOT use FelPro kit if you do valve adjustment. Both #1 and #4 plug well seal looked as it they were "torn" in the middle and both resulted oil leak. The fact it worked for about 2 years and 14K miles and the tears being in the center indicate the quality issue, instead of the workmanship. See the attached photo where you can see the tear for cyl#1.
 

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