Help!! I'm going to get hit by a semi truck!! Random stalling, stumbling idle

[wawazat??]

Dear Tom,
xoxoxoxxx

Love,
Todd

[TomsSVX]

Originally Posted by wawazat??

Dear Tom,
xoxoxoxxx

Love,
Todd

Name is Tom, not Mike

Tom

[wawazat??]

Originally Posted by TomsSVX

Name is Tom, not Mike

Tom

ZING!

Haha

[macadamianut]

OK,

So this weekend I plan to check timing (alignment) and spark from the coils.

What is the proper way to check for spark from the coil and plug without damaging anything? Can I simply pull one out at a time and test again the chassis? Or do I need to ground the coil by the mounting bolt before trying?

Which is the #1 cylinder? I need to find TDC to check timing. A diagram of the cylinder numbers and firing order would be cool. I haven't found it yet, anyone know?

Planning to order a front coil and move from one location to the next and hoping to find a bad coil causing this. Still wondering if the cracked outer insulation on one of my crank sensor wires could be causing this whole problem. I shrink wrapped/taped it back up. Order a new lower harness?

Man, there is a lot to think about here.

Thanks

[SoCal LS-L]

A spark tester works great, or you can use the plug and just ground it.

You dont have a diagram of the cylinders and timing? I thought you already downloaded the service manual linked in my signature. Its in there with some more useful stuff.

I wouldnt worry about the cracked insulation, unless the bare wires are touching or grounded its not the problem..... mine is cracked also but runs fine.

[macadamianut]

Whoops,

I did find the info under "specifications". Must have missed it before.

Do I have to remove the crank pulley to check timing or can I sneak in somehow?

[SoCal LS-L]

Originally Posted by macadamianut

Whoops,

I did find the info under "specifications". Must have missed it before.

Do I have to remove the crank pulley to check timing or can I sneak in somehow?

There should be a timing notch on the pulley to match with the cover marks, each cam has a notch and corresponding mark on the rear timing cover.

[macadamianut]

Broke down and ordered a new TPS and a new front coil, even though they are DVOM testing fine. Will try moving the coil from hole to hole and hope to find a bad one. Should be here tomorrow.

Will update.

Thanks again for all the insight and help.

PS. Tom, were you able to find a loaner MAF? I can send back the test sensors asap or wait for the MAF and ship back after the test/purchase of that.

[sowise]

Mac I can't help but get the feeling when it is all said and done this will be a forehead slapper. Best of luck though hope you find it soon.

[TomsSVX]

wait for the MAF to send them back... gotta dig one out give me a bit

Tom

[macadamianut]

After installing my new TPS, which made no change, I noticed a distinct sucking sound momentarily when I whack the throttle open. Sounds like it is coming from the PCV area. Is it possible to have a vacuum leak in this area???? Either the hose or valve threads???

Thanks,

[Trevor]

Originally Posted by macadamianut

After installing my new TPS, which made no change, I noticed a distinct sucking sound momentarily when I whack the throttle open. Sounds like it is coming from the PCV area. Is it possible to have a vacuum leak in this area???? Either the hose or valve threads???

Thanks,

Kia ora Mac,

The PCV utilises manifold vacuum in order to purge the canister and therefore the answer is yes.

The valve should be closed when the car is not in motion and certainly when the ignition is not on. The old puff and huff test will work for you, if you disconnect the tube running to it from the canister. Don't suck it to see. Blow by blow, is the answer.

As you suspect there could well be a leak, not involving the actual valve mechanism. While blipping the throttle, listen using a piece of tubing as a stethoscope .

Best of luck, you deserve some.

[hairy]

I am now watching this thread VERY carefully as my JDM SVX seems to have developed a similar problem, it has hiccuped and stumbled several times while trundling along at about 50Km/hr in traffic and twice has stalled completely (turning into my street and at the barrier in a carpark) in the last couple of days.

I took it into where I get it serviced (SubTech in Penrose) and no codes came up, they suspect the MAF as they have come across similar problems in other Subarus.

They had no room today so they are going to dig a little deeper tomorrow.

I will let you know the result.

[macadamianut]

Well,

I gave up and dropped the car at yet another Subaru dealer. I need my daily driver back up. Its been two months now and a lot of wear and tear on the 968 on our really, really sh***y roads here. I can say that 968's make excellent daily drivers though even when it's 10 degrees F and snowy outside (I have snow tires for it.).

They are diagnosing a bad MAF and base this off of running the car without it and having good results. They want $700+ parts and labor?????

$700+ is a strange number considering that the MAF new from most Subaru dealers is only 400ish. So that means they want 3 hours labor to install??? (It took me less time to reinstall the upper plenum for the first time I tried.) Just crazy.

I did try swapping in a used MAF from a junkyard earlier with no results. I am confused as to how they came up with this. And, just how do you make the car run without the MAF connected?? I couldn't figure that one out.

I will speak to them about the price of the part and labor and show them evidence of other Subie dealers charging much much less than that. I do want them to be satisfied too as they may get the car right back again and I don't want to be paying twice. They will want their tech to install and use their part if they are going to warranty the repair.

To update since the beginning of this thread:

-New coolant temp sensor
-New TPS- set to 0.485v
-New Front Coil in #1 cyl. (never got time to move around)
-Cleaned TB and By-Pass Air
-Removed Purge control system enitrely and re-vented under car through skid plate.
-Checked timing
-Measured all coil resistance - same
-DVOM resistance test on knock sensors - good
-DVOM tests on MAF all checked out, I even smacked the thing a few times
-New vacuum lines under manifold - all
-Cats are not glowing
-No good codes
-Unplugged injectors one at a time - all good
-Plugs - good, all similar and proper heat (huh?)
-Cylinder compression - 175-183psi
-Seafoamed the car twice.
-New alternator
-New upper plenum gaskets
-New vac lines to EGR and FPR to manifold
-New bosch iridium/platinum plugs
-New PCV
-New fuel filter
-New OEM paper air filter

And possibly now a new MAF. Man, I sure hope this works.
Thanks.

PS. Tom, if you have already sent the MAF, I may tell them that I'll take the car back for now to try yours. Send me a PM and let me know what you want for yours. If not, I should probably just suck it up and pay them. I need to get this car back on the road, stat.

[hairy]

It turned out that my MAF just needed a clean...............I love CRC MAF Sensor Cleaner.

$700.............WTF?

I hope it all works out for you.