Went to pull out into traffic tonight. My 996 lost power, then regained it and moved forward, then lost power, then went on as if nothing ever happened. 2nd time for me.

Don't know where to begin looking.
Does anyone have any advice to give?

996 C4 2001 with 95K

 

Sounds like dirty fuel injector.

 

I'll check that out right away. Thank you.

 

did you get a CEL? failing clutch switches can give that reaction as well as injector skips.

do you have access to a code reader?

 

Yes, code reader threw me P0470 and P1411, so that's torque converter clutch solenoid circuit Open; and, secondary air injection system (respectively).

 

both or either can give your car the stutters. are you going to continue the repair yourself?

 

Yes, I plan to repair myself. So far, I'm thinking to check ATF level (add), replace TCC solenoid, reset error codes and re evaluate. Though I'm considering just replacing all ATF.
I think that will handle the transmission issue. If you have advice, then I'd love it.

As to the other code, I'm confused, because I replaced the secondary air pump just 1 year ago. It sounded like a buzz saw. I don't hear anything wrong with the pump this time, so I'm not sure why the error code on this one.

 

Seems like it's not getting enough air when needed. Is the air filter clean? I think you need to be looking towards air blockage somewhere. Good luck.

 

MAF? Sometimes on other cars this is a symptom. But, i think that usually throws a CEL.

 

Sounds like a MAF problem to me also. The TCC solenoid will cause no lock-up or a stall at stops or lock/unlock jerk, but very noticeably different from loss of power. During secondary air function/monitoring the DME ignores 02 sensor readings therefore will not cause an inaccurate A/F mixture( relies on set program map without feed-back) unless secondary air pump is pumping/adding air while in the normal closed-loop mode (unlikely). A dirty or failing MAF will cause extremely rich or extremely lean conditions intermittently because it is the most relied upon sensor with the widest normal operating range 14kg/hr to 1800kg/hr , any reading within that range is plausible to the DME therefore will not show a fault. Usually MAF failures are detected by the DME as fuel mixtures at idle too rich or too lean (or a rare failure of below 14hg/hr).

 

Thank you for your responses re MAF and air/fuel mixes, guys. Appreciate it.

 

Porschetech3,
Left side exhaust just started putting out blue smoke upon cold start yesterday. Any experience with this? 96,000 mi., 2001 996 C4. Am I just lucky?

 

Blue smoke on cold start up is very common on flat six engines, and normally does not indicate a problem (some do it and some don't)unless it is extreme or sustains for a long period. Due to the horizontal piston /cylinder design oil can seep past rings more easily than V or in-line engines. Having smoke just on one side is a bit odd unless the engine was tilted a bit while sitting. If this condition persists on every start up ( just on one side) it can be an indication of a scored cylinder/piston on bank 2 cylinder 4-5-6. I would have someone look into the cylinders on bank 2 with a borescope to check for damage .I hope this is not the case but I have seen it on quite a few m/96 3.4 engines on bank 2. If scoring is significant it will usually be accompanied by a ticking or tapping on that side of the engine. If this problem just started at the same time your drivability issue started then the smoke could be the result of A/F mixture being so rich that it washed down the cylinder and caused the smoke on start, if that's the case fixing the drivability issue will solve both problems.

 

Wow. You know a lot. I will start with cheapest, easiest fix first: check codes again, replace 2nd air pump ($105), look into MAF (haven't checked cost yet), look into borescope (haven't checked cost).

 

I had the same hesitation on acceleration on my 2000 C4, and I was also getting a CEL. I replaced the MAF and the issue went away. I had previously had the CEL and minor hesitation which went away with a MAF cleaning. This kept me from replacing the MAF for a few years, but then cleaning the MAF no longer worked, so I had to replace it.

I bought it on Amazon for about $160.00. If you decided to go this route, check the part number since there are a couple of different types.