Mysterious Stall Issue.
 

The car is a 97´ Civic SI.
EJ9 (hatchback)
The engine is a D14A4.


Symptoms; Loss of power, sputtering, misfire?, intermittent stall.
Stalling is the number one concern. I believe the sputtering may be connected, i.e. the sputters are "near-stall" incidents.

The engine will start and the car will drive. But after a while, it just stalls. It can sputter once or twice, or it will simply stall without warning. Feels like stalling is less common on a cold engine.

The car used to have some issues with idle speed fluctuation after warming up, but I think this got a lot better after I took apart the throttle body and Idle Air Control Valve and cleaned them.

My car does not have a Fast Idle Thermo Valve.

The TB and what I could see of the intake manifold where really mucky. Seemed almost like there had been spilled engine oil in there, in addition to the carbon build up and such. Might just be the coolant that runs in there (for some reason).

Before the TB and IACV cleaning, I replaced the timing belt and did the valve clearance. Didn't seem to affect the progression of the problems (was happening before and after). Engine runs fine when it runs. See video.

The spark plugs are new and they all work properly. There is visible spark on all four. I assume from this that the distributor/wires need not be changed.

-slight- excess of O2 in exhaust. According to the guy who did the road security check. There is also a small hole in the pipe.

Should I consider problems in the fuel delivery system? Main relay? Pump? Injectors? Can I troubleshoot these without expensive shop equipment?
-Edit: Have tested both ignition switch and fuel relay excessively. No malfunctions on those. Could still be issues with injectors / pump /electrical supply-

The MIL (aka CEL) works, but is not on when the engine runs. Allegedly there are no codes. (Is it possible to find codes without a lit MIL?).
-Edit: Took a closer look at the MIL. Seems like the ECU records errors properly. Still I have no error codes except the ones I induced.-

-Edit: I am now leaning towards a compression problem. Will update after I test that.-
-Edit: Wasn't a compression problem. Considering options.-

Re: Mysterious Stall Issue. Please help. (+video)
 

I don't think its the ignition switch, but I'll ask

Are you having a hard time cranking the car? It looks like its a sensor issue, the ect sensor probably.

Also when was the last time you replace the crankcase pressure valve?

Re: Mysterious Stall Issue. Please help. (+video)
 

Cranking and starting fine. Has a habit of not starting after a stall. I think this got slightly better after cleaning the IACV though. It seems like part of the problem was in there.

I dont think its the ECT sensor. The car doesn't have any issues with overheating. (but the idle issue ocurred after warming, possibly because the car lets in more air on cold startup. all startup is cold startup where I live).
Also, wouldn't a botch ECT cause a CEL and code?

I looked in my service manual for a crankcase pressure valve, but all I found was a Positive Crankcase Ventilation Valve (PCV). Are these the same?
(It has probably never been changed.)


Oh and thanks for helping me!

Re: Mysterious Stall Issue. Please help. (+video)
 

Its not about overheating, the ecu needs a reading from this sensor, not your gauge. I've heard people have issues with the car just dying out at the red light because of this. You're gonna have to do some troubleshooting. Why didn't the CEL light come on?

Yes the PCV is the same.

Re: Mysterious Stall Issue. Please help. (+video)
 

It's defiantly not fun when this happens man you to through endless s**t. My 95 prelude had a similar problem and I couldnt figure it out nor my dad so I took it to Honda and it was diagnosed with "red dust" in the distributor cap. Mechanic said he cleaned it up and it ran like a dream.. Lol I wish you the best of luck man.

Re: Mysterious Stall Issue. Please help. (+video)
 

Thanks man. Its a constant man-vs-macine battle over here. You know, I actually took it to a dealer/mechanic, and the incompetent SoB didnt even take the time to wait for the symptoms to occur. :thud: He called it fixed and asked me to pay full price. :crook:

Oh. That makes sense. But since it goes to the computer, shouldn't that mean it definitely warrants a code/CEL when defunct?
As mentioned the CEL (just the light/LED itself) works, as it comes on with the engine cranking, and then goes off.
The "mechanic" said there where no codes but I don't trust him. Is it possible for there to be a code without a lit CEL? i.e. if the connection between the ECU and the CEL has been severed?

Re: Mysterious Stall Issue. Please help. (+video)
 

You'll need to find a way to monitor all your sensors to see whats going on.

Re: Mysterious Stall Issue. Please help. (+video)
 

Did you or a mechanic do a cylinder(s) compression test?

Re: Mysterious Stall Issue. Please help. (+video)
 

[QUOTE=hondacivic97si;50233592]Thanks man. Its a constant man-vs-macine battle over here. You know, I actually took it to a dealer/mechanic, and the incompetent SoB didnt even take the time to wait for the symptoms to occur. :thud: He called it fixed and asked me to pay full price

They tried doing the same with me but because it was through Honda I made a stink and they took care of it along with free valve adjustment 👍👍:thumbup:

Re: Mysterious Stall Issue. Please help. (+video)
 

[quote=zigerog;50234261]Man, I wish I could do that, but its a now unaffiliated shop and honestly I don't think they know what they're doing so Id rather not leave my car with them anyways.

No. Is this concerning the carbon build up in the intake manifold? Could this be a broken valve?


Edit:
Id love to take a "Scanner Danner" approach to this, but I just don't have the hardware. Whats next? Scrap it? Oh god please no.

.

Re: Mysterious Stall Issue. Please help. (+video)
 

By the way. I have now inspected the ignition switch -very closely and in every possible way- and it seems to operate properly. All circuits work, where they should and when they should.

Also, the Main Relay (pgm-fi) seems not to have any visible cracks or faults.

Edit: I have now hot-wired and tested every working circuit of the PGM-FI main relay directly. Unless it has to heat up to malfunction, they all work properly.

I also changed the fuel filter just to see if it was clogged, honestly it looked like new.

No change. Kill me now.

Re: Mysterious Stall Issue. Please help. (+video)
 

If your compression is low (worn compression rings(s)) in one or more cylinders it would cause loss of power, misfires and stalls. Easy to test with a friend and a compression gauge.

Re: Mysterious Stall Issue. Please help. (+video)
 

Ok thanks for the tip! =)

Re: Mysterious Stall Issue. Please help. (+video)
 

I had a similar problem with B16, when I revved it the tach would drop to zero and then the car would stall. I pulled the cap off the dizzy and spring that goes on the coil fell off. Replaced the coil and very thing is fine. You may want to take a look at the coil

Re: Mysterious Stall Issue. Please help. (+video)
 

I dont think that is relevant in my case, as the engine seems to handle revving pretty nicely. If anything, I can keep it alive longer by keeping it at about 3K.

I am now leaning towards a compression issue, as suggested by Jimi Hondrix

Re: Mysterious Stall Issue. Please help. (+video)
 

I have now done a complete compression test. Both cold and Warm and with a bit of oil.

The compression is spot-on. All are around 13 bar with minor variance. (≈188 Psi?)

Also the timing is not off.