HELP! Weird driveability problem

[releese78]

The problem seems to be getting worse!

Tonight, when I first left the house, I got about a mile before it started sputtering, I pulled off the road and it stalled.

Later on, well after it being warmed up (about 20 miles after it driving great), I was accellerating in 4th gear at around 70mph when it just choked. I put the throttle to the floor and it was completely unresponsive. From there, I drifted to a stoplight and when it turned green, I went no-where. I pressed the throttle and heard sputtering and backfiring, barely moving at all, it did this and all of the sudden...BAM, it woke up and ran like a bat outta hell again.

I'm about ready to just start throwing parts at it (starting with MAF and O2's). I've been through and heard many horror stories of vehicles being at the dealer for weeks at a time and thousands of labor dollars only to be told "we can't duplicate the problem" or "this should fix it".

Any other suggestions or input would be greatly appreciated. Fuel pump? vaccum issues? AOS?

[Lil bastard]

I cannot believe you're having problems to the extent you've described and are still driving the car !!

I presume you know the definition of a person who keeps trying something, each time expecting a different result?

These motors have been known to implode with little provocation and to keep driving one that is signalling to you all is not right ain't the brightest tactic.

You can pull out the 'ol Mechanic's Dartboard and throw hundreds here or hundreds there in hopes of serendipitously curing the issue.

Or, you can take the logical approach and get it to a qualified person with the proper diagnostic tools and actually find out what's gone wrong and target your $ to the proper fix.

Everything posted here is speculation to one degree or another, and advice is cheap - it's not our car! Someone may have suggested what could turn out to be the proper fix, but until you either buy and install all these parts, or get it properly diagnosed, it's all just guesswork!

Talk to the Service Advisor, ask him how much it would be to pull the codes and records and inform him not to proceed until you have given him the OK. Have him put the service charge on the service order beforehand and sign it, retain a copy. That will protect you from all your fears about a dealer.

[hjkim550]

r78,

I would listen to Lil if I were you. Sound advice if you ask me. Your adventures are starting to get pretty dangerous.

If you are concerned about reputable dealers, you should look at the thread: Find your local mechanic/ porsche specialist. It is a long thread but the last page has a convenient list and links to other helpful threads.

In my line of work, people would think I was nuts if I suggested treatments and cures before a careful and thoughtful diagnosis. Just my two cents.

[insite]

if you want to know for sure if it's the MAF, unplug yours and go for a drive. the car will use a default fuel map rather than sensor driven maps. if the MAF is the problem, your drivability issues will go away.

that having been said, if this were the MAF, O2 sensors, etc, you'd be getting codes left and right. when you put your key in the ignition, turn it to the ACC position but don't start the car. make sure the CEL lights up; it's possible the bulb is bad.

if still no codes & MAF is good, take it somewhere. throwing parts at the car is an expensive proposition. it's cheaper in these circumstances to pay the guy. i'm with the others; fuel starvation sounds likely. stop driving the car if you can.

[insite]

you know, another way the car can starve for fuel is if you have a vacuum leak. check to make sure the intake tubing is all connected and not torn. listen for any hissing in the engine bay. i usually wave around a propane torch (unlit of course) in the engine bay; if there's a vacuum leak, the RPM's will jump.

[releese78]

***UPDATE***

Well, I took your advice...almost.

I checked for vaccum leaks, found none. I did find something very weird though. On the passenger side, coming out of the rear firewall (near the coolant and oil hoses), I see what appears to be a vaccum hose (approx. 1/2 inch outside diameter). This hose has no vaccum and doesnt have any type of fluid coming from it. I looked all over for a place this could possibly go and didnt find any open ports, nor could I tell what it is connected to on the other side. When fully extended, it almost reaches the vent fan, and also has a black "half-moon shaped holder" that probably kept it against the side wall somewhere. Weird?

I think I fixed the driveability issue though! Keeping my fingers crossed! I pulled the MAF again and noticed that the sealant (on the side which holds the rectangle plastic cover in place) to be cracked almost all the way around. Rather than chance it, I purchased a new one, which wasnt cheap since mine is a 98 without e-gas. It's been over a week, approximately 200 miles driven and all seems well. Only time will tell though.

As for the tranny problems, I purchased a filter, gasket and fluid from the dealer, (still waiting for the gasket to arrive, it was backordered) and I'm going to do a service on it. Speaking of gasket, has anyone had any good or bad experiences just using the gasket, or RTV, or a combination of both?

On another note, I've been seriously considering purchasing the ZEINTOP, I've spoken to them on several occasions and although I'm not rich (actually quite the opposite!), I think I'm going to drop the cash to do so. I'll be sure to post pics on here since my car is white and I havent seen one in that color yet. I'm told that it will take approximately 6 weeks for delivery.

One last off-topic question, can Durametric turn on the OBC? or is there any "home tool" which can? I was thinking of buying an inexpensive scanner, and want to kill two birds with one stone.

Thanks again for all of your help and input!

[Lil bastard]

Well, as far as a gasket sealer, I would NOT use any type of RTV or such. These provide a hard cure seal which can then be broken by heat and vibration - exactly the environment you're using it in.

When I did my Filter/Fluid change on my Tip S it was only at 25k mi., but the gasket was leaking. Since there is no dipstick for the ATF, there was no way to know what the level was at. Since I needed to remove the pan to replace the gasket, I swapped the filter and fluid while I was in there. See my DIY in the DIY section.

I used Hylomar as a sealant rather than RTV. Hylomar is a polyester/urethane sealant originally developed by Roll Royce as a sealant for their Jet Turbine Engines. It is a non-setting, non-hardening sealant and so is both vibration and thermo-expansion resistant. It is also a zero-tolerance sealant which means that in some applications where you would need to account for the thickness of any sealant, you can use Hylomar and remain at factory specs - it does not alter spec tolerances. I have used Hylomar for many years and have never used RTV Silicone since - it works that well.

It was licensed to PermaTex, but I understand they now longer produce it as it competed with another of their products. But, Hylomar is available from Hylomar USA marketed as Hylomar Universal Blue. At $28.50 for 100gm (3.5oz.), it's not cheap. But, you use very little when using it as a gasket sealant and 1 tube will last for years - it has an indefinite shelf life. Plus, used as a gasket sealant, it will NEVER leak again, unlike RTV, so that alone makes it worth the cost. See it at: http://www.hylomar-usa.com/

Also, the Durametric will not activate the OBC, only a PIWIS or PST2 can be used. My dealer did it for free when I had the car in for some other work. Others I have heard have charged $60 or $100 to do it while still others have outright refused to do so. Seems the best tactic is to ask them to turn on the temperature display, never letting it slip that you're planning the OBC Hack.