84_Carrera

...So the bucking issue's back with a vengeance.

I've been noticing that you sometimes can "push" through it with more fuel (rich - black smoke), then it passes, and sometimes you just can't. If I catch it right at the beginning of the buck / hesitation and push the clutch in or dump it in neutral, I can often see a 1k - 2.5k rpms rev surge, which passes. At idle, no issues.

Today it got really bad, and stalled on me going up a hill in 2nd, ~2k-2.5k rpms. I'd get her re-fired, give it gas & it'd bog & stall again while in neutral on the side of the road. After letting it idle for a few minutes, I was able to get up the hill with some hesitation, then it completely passed and drove normally, until I shut the car off upon reaching my son's school to pick him up (more on the idiotess that parked next to me shortly).

Upon leaving for home, the car did the same exact thing about 10 minutes later (not before, not again after).

I have a Cylinder Head Temp Sensor on order with Pelican already, and the hoses look ok. I've replaced the idle air valve already, fuel filter's been done in the past 1-2k miles.

Any other ideas, or is the concensus the HTS?

Back to the school parking lot - I'm in the last stall, nose-in, open lane on my left, and I'm sitting in the car waiting for my son. A woman backed her SUV perfectly parallel to me, driver's door to driver's door (again, in the driving lane, not a spot). She decided that it wasn't quite right, so she pulled forward, then backed in on an angle this time, her nose to my rear quarter, and about 6" closer to my car. I'm like, "Ok, you don't want me to leave before you or anything..." as there was little clearance on my rear Q. She opens her door... RIGHT INTO MY MIRROR. She gets out, appears to finally notice that I'm sitting in my car, pauses to see if I was getting out so she could pass the blame my way somehow, sees I'm not moving & am just sitting there glaring at her speechless.

"Oops." And walks past me to the building, making sure to set the alarm in her SUV with a honk of the horn. AAAARRRRRGGGGHHH!!!

Oh, yeah, and it was sunny & mid-70's today, I had the day off from work, and was able to go driving in my 911. I guess that's the therapy I needed for idiots like that.

Corrales911

Bad mass air flow sensor or O2 sensor can cause weird problems like you mention...

84_Carrera

Ok, I did remove / transfer the old O2 sensor from the cat to the pre-muffler awhile back, (well) before the problems started. Does unplugging the sensor revert the computer to a pre-set condition so I can check that out, or will that make no diagnostic sense?

Chris(MA)

"Oops." And walks past me to the building, making sure to set the alarm in her SUV with a honk of the horn. AAAARRRRRGGGGHHH!!!

Stupidity is the worst disease of man (or woman).....

84_Carrera

I should have elaborated a little on the condition...

only when hot, driven for about 10 minutes or so, oil temp just below the 1st line (hotter than the bottom solid block). Will only have one episode per running cycle (so far).

Had a brief "stutter" condition like this before, replaced the original(?) DME relay, problem went away for a short time, then returned. The one I put in was a spare purchased by the PO, I bought a new one this year for glove-box insurance.

pjc

Could this be a fuel pressure problem? Seems unlikely I know but any port in a storm.

PJC

rbcsaver

Do you have a reusable (K&N) oil filter installed. Excess oil can muck up the MAF (personal experience) Try spraying intake cleaner (NOT carb cleaner, they are different) can't hurt and will clean out years of dirt. Does sound like it could be a bad head temp sensor more unlikely the O2 sensor, but if that is original to 84 then it too is past due for replacement. I've replaced both on my 84 with the head temp sensor the biggest PIA.There are threads here and Pelican on the subject with pics. You'll need to cut a slot with a disk grinder in to a 14mm deep socket length wise for the wire.

84_Carrera

I was considering that it may be fuel pressure related, as the rpms surge under no load during the occurrences.

Yes, I have a K&N filter in there, installed by PO. I do like the K&N filters, however you can't oil it nearly as much as it comes out of the box on a heated MAF type car (assume there's some kind of heated element if not MAF on the 84). My own personal applications for them, clean it extremely well, let fully dry, then BARELY wick enough oil from the container (never use the spray, IMO), just enough to change the color to a light pink. If it looks red, it's too wet.

If the masses believe the K&N is a no-no on this car, I'll happily go back to paper. Whatever's best for baby.

I may swap the O2 anyway, figuring it's probably due. I'll go back through the paperwork & make sure it hasn't been done in the past couple of years.

Edit: Hey Steve, did you get a new socket from Sears?

rbcsaver

I still use a K&N on my 84 and yes there does seem to bee a board concensus to stick with the OEM. Suggest you try the intake cleaner (NAPA, Autozone, etc. ) Yes, it was a new Craftsman 14mm deep set socket. It was only a few dollars, but I think I voided the warranty.
Regards,
Steve

g-50cab

I'll put money on the cylinder head temp sensor

84_Carrera

Well I got in my clutch helper spring & cable last night, with luck Pelican'll have the HTS etc in my hands shortly & we'll do it all. I'm still debating about doing the O2 at the same time... one part of me wants to figure out the true cause by replacing one part at a time, another part says "do it all at once". Too bad the O2's are so expensive. Cheapest I found for the Bosch 13003 (92860612400) was $150.09 after a 5% discount. Looks like later 80's Carreras used a much cheaper O2 - I wonder what it would take to convert? PCM replacement, or is it a different harness, etc?

emac

Fred
I had a problem somewhat similer to yours. My car was running perfect and out of the blue at 5g she would start to shake and shudder. I tried everything, new gas filter, injector cleaner, plugs, wires, cap and rotor. It was getting dark and I was ready to give up and just as I reached to shake the plug wires I seen the blue flash. I had a small wire that came loose from the + side of my coil. I changed the five cent spade and the car has never ran as good. I realized that at 5 g she shook just enough to ground the wire. Might not be but its worth a look.
As far as the lady, happened to me one day but not in my P car. I was soo pissed that the party didn't care that I opened my trunk and placed my golf shoes on. I then did about a five minute gig on the subjects hood. Might have been the wrong thing to do, but I but that person will NEVER walk away from a dented door again.

carnutzzz

Fuel filter? Melted cat?

84_Carrera

Filter was replaced, and I have a Fabspeed Euro-Premuffler in there.

Dan Cobb

Golf shoes on their hood?! That is a bit too much if you ask me.
Hey, I'm no saint, and i have definitely bumped a car door or two in my day.
I changed my thought process on it all about a year ago though. I pull my big Chevy dually into a spot at Home Depot. When I get out, I realize that I am a bit closer to the new Escalade than most would prefer, but I cautiously open the door and exit the truck. I didn't think I hit it, but I looked at their door just to be sure because i saw a mark on it.
It was from a red car/truck and mine was black. I was in the clear...or so i thought.
When I came outside, there was a 4 foot long key mark through both of my left doors (crew cab) and the Escalade was no where to be seen.
What a jerk (to be polite).
Anyway, I always try to park on an end spot and i crowd the curb if possible to leave a little extra room for the soccer moms and rednecks. Fortunately, I haven't had any parking issues with the 911, but i do know/understand t your frustration.
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