3.2 hesitation issue revisited (long)

Steve Viegas · 09:39 AM

A few years ago I purchased a 1985 911. It had a stumbling/hesitation issue. I was not too concerned about it at the time. The PPI lead me to believe it was probably nothing to worry about and that it might clear itself up.

I promptly lost my income.

I had a mechanic look at the problem. I described the issue, and he drove the car so that he could feel the issue. The problem is the car briefly hesitates around 2500 RPM, and then stumbles badly at ~5200 RPM and will not go beyond that. The mechanic replaced the AFM as well as the distributor. No help. He suggested it might the DME. At this point, I was out of money and I would not be able to chase this problem down.

Luckily for me, our local DME expert Ischmitz, was able to lend a helping hand. He was in the area, had a known good DME and let me try it out, although he did not think it would solve my problem. He was right, but saved me a ton of dough. Thanks again.

Years later, I still have this problem, and unfortunately, I still have no income. I do however have a new symptom!

I can now state, that the stumbling at the upper RPMs absolutely gets worse as the car gets warm. When cold I can get the car up to almost 5500 RPMs when it starts to stumble and refuse to go any higher. When the engine is warm/hot it seems to find its upper limit around 4500 RPM.

One more point, under no load I can get the engine up to 6000 RPMs with little to no issue even when warm.

Anyone have an idea of what I should check next? A few years of this problem is getting...tiring.

Here is the original thread, sorry for starting a new one...
3.2 hesitation

Gemballa2006 · 08-26-2010, 09:12 AM

By no load I assume you mean with the car in neutral or with the clucth in and under load meaning while in gear with the car moving? If that is what you mean then I can only assume it is the transmission somehow retarding your ability to get the rpm's up. I say this becuase if you can get them up when not under load you pretty much eliminate the engine as the problem. This of course is just speculation but it makes sense to me that the transmission is the issue. Have you drained your tran fluid lately, that may lead you to some conclusion and doesn't cost that much. Has there been any work done on it in the past. Just my 2 cents, I can't wait to hear what everyone thinks, someone must have an answer

Steve Viegas · 08-26-2010, 09:22 AM

Gemballa2006,

Thanks for chiming in. You are correct in assuming that by "no load" I mean with the clutch disengaged and by "load" I mean with the power being transferred to the rear wheels.

My mechanic seemed to think it was something with the ignition system and he did not seem to believe it was a transmission issue. I too look forward to seeing what others think. Perhaps they will agree with you.