‘88 911 3.2 jerky / cavitation

[Marc718B]

Hi everyone. New to the forum and to air cooled Porsches. Today was the first day I was able to drive the new to me 88 911 3.2 and everything went great. It had almost an empty tank so stopped at an Exxon and filled it up with Premium. I then drove back home without any issues. I decided to wash the car (as it was extremely dirty) and after all said and done we went out for dinner on the new car. As soon as I started I felt the idle was a bit rough. When starting to drive it on 2nd and 3rd felt like a jerkiness / cavitation when between 2K and 3K RPM (not sure if that explains it, it was like power was coming and going). Any ideas on what could it be? Could some water affect anything in the engine that would behave like this? Or could be the fuel? I have an appointment already with a mechanic for Tuesday to do some other stuff and will let him know (if it is still doing it) but wanted to check if you guys could think of anything.

Thanks!


Sent from my iPad using Tapatalk

[Driven97]

Factory airbox?

[mo-mon]

Check that all spark plug wires are well seated. Could be gunk in the fuel filter. Don't allow your fuel to be below 1/4 full. You should fill up when the gauge reads 1/2. 911's like a full or near full tank for optimum f/r balance.

Post pics of your '88.

[Tippy]

Pull the distributor cap and liberally spray everything with WD-40.

Spray outside of cap too.

Let’s hope you just got the dizzy wet (very high probability), as these cars display these symptoms when other things are the culprit EFI related and are tough to figure out.

[kyngfish]

Has it been sitting for a long time? Not driven much? You may also want to get it good and hot and then floor it a few times. But yeah, check spark plug wires and etc first. I used to get some hesitation under load and I ended up giving her an italian tuneup - a few big clouds of black smoke and she's been running awesome ever since.

[Marc718B]

Thanks all for the feedback. It is stock, but the fuel filter seems it was last changed in 2012! I have that on the list to change. I’ll check on the other recommendations. Found some other threads out there and they seem to call this behavior “hesitation”. I’ll also do the Italian tuneup and see if that helps but it was interesting it started happening right after the wash.


Sent from my iPad using Tapatalk

[DRACO A5OG]

Sounds like fuel starvation ergo Clogged Filter.

Wash could have soaked the dizzy or if you drowned the forward area of the D-side wheel well where the ref/speed sensor sits could affect it but this situation would clear up soon as you drive her and she starts to dry.

I vote fuel starvation.

[da Vinci Dan]

My hesitation turned out being a bad #3 plug cable connector:

As you are going through the ignition, inspect the wires and boots too.

[Tippy]

You washed your car, now it sputters. Classic wet ignition symptom.

Italian tune up will not help that.

[Marc718B]

Thanks everyone for pitching in! I drove it briefly this morning and the issue is gone. I'll test it again this afternoon but will do a couple of the items people mentioned above as well (don't think it will hurt - like WD-40, checking on ignition and inspect wires and boots). Next Tuesday while my mechanic checks everything out he will change the fuel filter (can't believe it wasn't changed since 2012!).

[jlex]

Could have ingested water from the gas tank when you ran it low. I'd put a can of dri gas in it to make sure the water is cleared out. Don't want water hanging around an injector.
BTW: change out the filter yourself. It's time you waded into the wonderful world of Porsche maintenance. Is a good entry point.
If you're changing the filter, it's my recommendation that you power up just the fuel pump afterwards for a minute or so to circulate the gas a bit to make sure any disturbed debris is captured by the filter and doesn't lodge in an injector. You don't know what dirt may be disturbed after opening the system. Starting the car up immediately afterwards may create a problem.

[Marc718B]

Originally Posted by jlex

Could have ingested water from the gas tank when you ran it low. I'd put a can of dri gas in it to make sure the water is cleared out. Don't want water hanging around an injector.
BTW: change out the filter yourself. It's time you waded into the wonderful world of Porsche maintenance. Is a good entry point.
If you're changing the filter, it's my recommendation that you power up just the fuel pump afterwards for a minute or so to circulate the gas a bit to make sure any disturbed debris is captured by the filter and doesn't lodge in an injector. You don't know what dirt may be disturbed after opening the system. Starting the car up immediately afterwards may create a problem.

Thanks jlex! I was planning on doing it myself, but will get my order from Pelican next Thursday and already had an appointment with the mechanic to check other things, so I'm just going to get him do all the stuff and I'll do it next time. My idea is going from just filling up the tank to doing most of the maintenance repairs myself (hopefully)!

[kyngfish]

It may not need the italian tuneup, but you should just do it anyway once you get things sorted, mainly because it's fun.

[DRACO A5OG]

OP COngrats!

[rokemester]

Amazed that I’m the first to say it? Pictures please. Congratulations.

[rdrr]

I've owned a 3.2 for 15 years. Whenever this happens to me, I replace the distributor and rotor.

Congrats - these are great cars!

[Marc718B]

I should have posted a photo on the first post. Here she is:




Sent from my iPad using Tapatalk

[stlrj]

I doubt it had anything to do with water in the gas since the tank is sealed but wet ignition cables and water infiltrating the distributor cap is more likely. If your're brave enough, try hosing your wires and cap and see how your engine starts to act up again.

Cheers,

Joe
87 Carrera

[Marc718B]

Originally Posted by stlrj

I doubt it had anything to do with water in the gas since the tank is sealed but wet ignition cables and water infiltrating the distributor cap is more likely. If your're brave enough, try hosing your wires and cap and see how your engine starts to act up again.

Cheers,

Joe
87 Carrera

LOL.. I actually thought of doing that... but will wait for the mechanic to do the test.. that way if anything get really screwed up at least he has it in his shop...:-)

[GH85Carrera]

I had an issue with washing the car and then poor running. I checks every spark plug connection, and the distributor. Nothing helped. Then I replaced the distributor cap, and all the wires and put in new plugs. It still did it.

Then I looked at the fuel injectors. One of them was acting up and the connector did not like water at all. I replaced that, and bingo, all is well. I now have a spare plug set I kept in case one wire or a connector goes bad.