3.2 Carrera Gutless unitl 4K Rpm

[Classic11]

Hello Community,
This is my first post and first of all thank you for all the information that is on this site, very very helpful. I have a current issue that I hope someone can help me out, I hat spending more money on parts that turn into spare parts :-)

I have a 1984 3.2 Carrera that was in storage for 10 years and even before then very lightly used. Overall 90K miles but most of them added in the 80’s.
I bought the car not running and before I even tried starting it I replaced: Fuel Filter, Oil and Filter, Spark Plugs, Distributor Cap and Rotor. It starts up and can be driven but shows the following symptoms. Starts up after a few turns and when cold does not idle great and almost needs some support from the gas pedal to not stall, after it idled for a minute it idles decent but sounds almost like it misfires at times or pops but overall OK. Does not smell like it is running rich. When driving it is gutless until over 4000 RPM where it shows power, under 4K it is really not a Porsche. When accelerating it is popping and not smooth but for me this is my first Porsche and 3.2 Carrera so I am not really sure how good a perfect motor pulls, but it has to be better than what I got.

So far I have replaced and checked the following in the hopes fixing the problem:
- New spark plug wires
- New CHT sensor (old one was the single wire still and had a resistor soldered in the wire for some reason, but all fixed now)
- New Speed sensor (old one measured good but replaced it and gaped to 0.8mm), Reference sensor is still the original but measures good in resistance and voltage at the DME
- Fuel Injectors removed and cleaned by CruizinPerformance (good service and test results)
- Replaced all hoses related to vacuum and engine ventilation including oil fill cap
- New DME relays
- New O2 sensor
- I have tried another set of spark plugs, same results
- Cleaned throttle body and new O-Ring
- Idle control valve is vibrating but not yet cleaned
- Checked Idle control switch
- Checked WOT switch
- I pulled the spark plug wires one at a time and idle drops slightly so I believe all cylinders are firing.

Fuel Pressure I checked yesterday and here the results I got. 2.5 bar with just the pump running. Holds this pressure for several hours.
When running pressure drops to 2.2 bar on idle, when I pull the vacuum pressure goes to 2.8 bar. When I rev up the motor pressure fluctuates first up then drops to 1.75 bar at times but picks back up quick. Without the vacuum pressure is steady at 2.8 no matter what the rev and vacuum does. I think this is OK but cannot find much info online on the fluctuation of pressure.

- I have not checked the coil, is there a good procedure to do so?
- Also the DME computer I read can make issues thinking about checking some solder connections inside. Hate to spend $500 dollars without knowing it is my issue.
- Anyone in the Atlanta, GA area that would let me test their DME? I can pay a fee or with beers :-)
- I see someone has messed with the screw on the throttle body before, is there a procedure to set this at least to factory settings?
Sorry for the long story, hope I get some feedback from you guys.

[ClickClickBoom]

Find/get a copy of the FSM. Throwing parts at a problem can get expensive, luckily the parts you have already thrown are normal wear items. The ICV is a known problem area, if it is stuck open it might cause some of your symptoms. This is also a wear item, so replacing it won't be a waste of money. Another often missed maintenance item is distributor lube, under the rotor. While you are in the dizzy, check the shaft for axial play as well as radial play. In other words no side to side or in and out. Rebuilding is a 2 banana job.
3.2 Distributor Overhaul...

[Classic11]

Thanks for the advice. I will clean the ICV valve tonight and see, maybe replace. Do you know how this valve is supposed to work? Is it supposed to be closing when not in idle? Is it controlled by the idle switch? What is the FSM? Probably a stupid question but not sure what that acronym stands for.

[jjeffries]

Factory Service Manual.
Best of luck to you. John

[76FJ55]

FSM see ^, also sometimes refered to as the WSM (Work Shop Manual)

also another common acronym is PET (Porsche Electronic Technologies) which represents the Parts catalog. the PET is available HERE on the Porsche website, and can be down loaded as a PDF.

[Duc Hunter]

I clean my ICV on my 3.2 by pulling it off the car, squirting brake cleaner or entropic parts cleaner into it and shaking. you should here is rattling and the valve moves. I bet what comes out if black. Do this several times until what comes out is clear. That will be al you need to do.

Then rattling is the valve moving. As they age they get gummed up and can not move fast enough or get stuck. Also make sure the electronic connection works it properly. Search out here for that procedure, I don’t remember it.

I assume you car makes good vacuum? Also try checking for vacuum leaks. I have started the car cold, and sprayed brake cleaner or carb cleaner around areas of vacuum (hoses, where the intake attached to the heads, etc). If the revs change you have a vacuum leak. Just don't spray it in a way that it gets sucked into the engine air intake through he filter, or this will give a false positive.

[76FJ55]

Back to your original issue; these are prone to having intake gasket leaks in addition to all the vacuum side pieces you've already replaced. These leaks are sometimes difficult to find since there are two gaskets and a plastic spacer at every runner connection to the heads. the lower gasket is below the cooling shroud and also under positive pressure due to the cooling fan, so it is hard to access this for troubleshooting. Vacuum leaks can definitely cause issues similar to what you are seeing. another test aside from just pulling plug wires to test for a dropped cylinder is to take an IR temp gun and measure the exhaust manifold temp where it comes out of the head. the temp on all 6 should be reasonable equal. If you have a couple that are significantly below the norm I would be highly suspect of the intake runner gaskets on those cylinders.

[911pcars]

Start with the basics. Do all cylinders produce spec compression test numbers? If so, engine structure and assembly is good. If never run before, maybe something more basic, like retarded valve timing. Shorting out each cylinder should result in a very perceptible difference in engine speed. If all cylinders show very little RPM drop, I'd suspect a system that affects all cylinders (e.g. valve timing).

S

[76FJ55]

With the ICV in operation, the computer will stabilize the idle speed, so you may not get a significant drop in RPM based on disconnection plug wires.

[otto_kretschmer]

I like to start investigating a questionable engine with a leak down test



you can buy or build your own tester

[stlrj]

Now might be a good time to get back to basics and not assume anything. Check your ignition cable firing order. Getting wires crossed is more common than you think.

[Bill Douglas]

Good advice from the guys.

You car should have good/reasonable power from 3,000 RPM. And be pleasure to drive.

Good luck and I'm sure it will come right.

[Classic11]

Thanks for the comments all. I have dome some more testing yesterday, I took out the ICV, cleaned and tested it with a 9V block battery. Looked pretty good and tested fine. I believe the valve was installed backwards, meaning the arrow pointing up but even after I installed it back arrow down and tested the car no real change. I noticed that when I removed the oil cap the motor stalls immediately. Which makes me believe it is fuel/air related, not timing. What you think?
The more I thought of @76FJ55 idea on the intake runner gaskets the more sense it made to me that it could be the issue. I sprayed brake cleaner while running and on the right bank the idle speed went up when it hit the cylinders but that is also where the air cleaner is and with all the air blowing when motor running cannot be 100% sure. So what you do, remove the intake at 10:00PM at night since this issue is killing me. I removed both sides with motor in the car and only think I found was that the gasket on #3 was broken and I think the insulator/spacer cracked. One bolt on that runner was also pretty much loose. I am pretty sure that there was some air being sucked in but not sure how much and that can be all of my problem? Just one cylinder causing that much of a power loss, not sure.
Recommendations on a good set of gaskets and insulators?

[Classic11]

Sorry I did not post a picture of my car here is one, 1984 M491

[76FJ55]

Beautiful car.

When I did mine I ordered the VR intake gaskets (qty 12) and the OEM spacers (qty 6) from our host.

[4flyboy]

Nice!

Welcome.

Where are you located? You may want to put your location in your signature.

['76 911S 3.0]

Sounds like it's running extremely lean. Have you looked into the barn-door MAF to make sure the wipers are not worn out and the sensor is reporting properly?

[darrin]

Originally Posted by '76 911S 3.0

Sounds like it's running extremely lean. Have you looked into the barn-door MAF to make sure the wipers are not worn out and the sensor is reporting properly?

this! the one thing you don't seem to have done is checked/adjusted the base/idle AFR --

[Classic11]

I am located in the Atlanta,GA area I will update my profile. I have the MAF off now, is there a way to test it? I have cleaned the MAF and the door is working well but not sure if the sensor of it is. I heard they are pretty robust.
Can the base idle AFR have that much of an influence? Sorry for all the questions but is there a good procedure to check and adjust?
I hope to have the car back together next week, I have ordered the gaskets and spacers now. Sure now I got it all apart I think I will check valve adjustment and do a compression test also to make sure I have no bigger issues that I am not aware of.

[jpnovak]

Originally Posted by '76 911S 3.0

Sounds like it's running extremely lean. Have you looked into the barn-door MAF to make sure the wipers are not worn out and the sensor is reporting properly?

Yes, this exactly. Then recalibrate the mixture once you have this fixed.

Follow this.
http://www.clarks-garage.com/shop-manual/elect-22.htm