Why is my 3.2 so slow??
 

I know there are a lot of guys on this board with 3.2s of various types so maybe you can help with this.

I am the current caretaker of an '89 3.2 cab and of all the 911s Ive come across over the last few years this one has thrown me a curve ball. Im not sure if its just me or something related to the car but the car is simply......... slow.

It has a SW chip and a Dansk 1 out exhaust which seems ok. The car is smooth, has an idle switch problem or something so it stalls occasionally but other than that it drives well. 80K miles, good history, just serviced and everything works on it. Its the performance that Im not sure about. Were these cars not meant to be about 6 sec to 60mph? This car doesnt seem anything like that.

I have a standard test for seat of the pants acceleration and comparing the cars I have this is how I see it:

Rolling start 50mph slightly uphill probably about a quarter mile. At the top of the hill the '75 turbo will be doing over 120mph, the Carrera 2.7 over 100mph but the 3.2 struggles to get to 85mph over the same distance.

Can anyone with experience of these late 3.2s let me know whats going on here?

Boy I'm no expert here what so ever, (wrenches and & are mortal enemies). If the car is in good mechanical condition could it be something as simple as the accelerator pedal not being properly adjustment?@ not getting all you can from it? Can you actually have a mate time you 0-60?
I'm sure a few experts will chime in.

Yeah the gas pedal and throttle position was my first thought also. All looks right though. I was planning on testing it against a friends new Golf GTI. Im worried it might be embarrassing Im afraid to say...

GTI diesel? Hope you can beat that.

Isn't there a full throttle switch that needs to close to get full power?

Do you still have the original Chip. If so put it back in to test. If its not the throttle it sounds electrical to me

Sounds like the car is firing on 5 cylinders...mine will run smooth enough on 5 to do what you describe.

Start basic: fuel filter, make sure all injectors are firing, check all the plugs to see if anything is fouled.

Make sure the throttle gets fully open. Incidentally, the black plastic switch on the side of the throttle body is not a throttle position sensor, it is just a rotary on/off switch to tell the DME its at full throttle and the DME then ignores the o2 sensor. The Bentley manual describes how to test and set all this. When I first got my 3.2 years ago I thought it was a TPS too, but it is not.

If all else fails get to a shop that can stick a wideband o2 sensor in the exhaust and find out what's going on.

Your SW chip is not the problem. If the car is stalling occasionally you have something else amiss.

I had a miss on very humid days (not in the rain, just high ambient humidity) other then that the car ran great, I think the 3.2 runs pretty strong on 5 cylinders. You should check your ignition wires, this is what my coil wire end to distributer looked like and the distributer end of the #4 wire (inside the boot). All the wires unscrew from the ends, worth looking at. When i checked the resistance of my distributer cap the coil post had high resistance and the #4 post was very high in resistance. I think the bad connections destroyed a relatively new dist. cap. Replaced the cap, two dist. end boots and the #4 wire. She idles smoother and has more get-up and go now. The one on the left was the coil boot to distributer, I'm surprise that the engine ran at all, the ignition is designed to have resistance at the spark plug ends of 3k ohms. So the story is even with very high resistance they run pretty well.

http://forums.pelicanparts.com/uploa...1259338442.jpg

IIRC, I've read somewhere that the barndoor (throttle air plate) that is located where the airbox meets the AFM box may sometimes not open completely at WOT, which would probably cause your problem. You should probably remove the airbox and test your barndoor, and make any adjustments as necessary.

To get 6 sec 0-60 you really have to get on it very hard. There are two ways to check the throttle switch. First have someone push the accelerator to the floor and see if it physically opens all the way, then while they are holding it open pull the connector off and put a meter on it and see it it is actuating.
The plug wires which were originals on my 88 started to fail. 15 to 20 years is a long service life for those. I replaced those 5 years ago with Magnacore's. Also if an injector is not operating that can do it as well. These cars can run amazingly well on less than 6 cylinders.

make sure you are getting full throttle.

Do you have the original cat?
The suggestions above seem most likely.
You say "just serviced and everything works on it". I would hope your mechanic could tell if it is running on 5 cylinders. After checking the electrical system and fuel system, consider that your cat might be plugged; it is rare, but often overlooked.

Thanks for the input. I will start checking again to see if it looks like its getting full throttle. I was assuming it would sound different if running on 5 but maybe not?

This car has a cat bypass installed too. I will have a look at the cap and wires and see if anything looks out of place but it sounds like the diagnosis will be beyond my abilities. Will have to go back to the shop to be sorted I suspect.

At least it sounds like there is probably something wrong and its not just unrealistic expectations.

I have a 77 with an 89 3.2 in it. When I got the car it was slow too. It actually ran surprisingly well but was, well, slow. It turned out to be many things:

1) The fuel filter was clogged

2) The 2.7 CIS fuel accumulator was still installed in the fuel system

3) The CIS fuel pump was providing incorrect fuel pressure to the Motronic system

4) One of the plug wires was severely corroded

5) The CO setting was way off

6) The intake boot clamp was restricting the throttle to about 80% open

7) The "brown wire" was jumpered on the ECU

I added a Steve Wong chip and cat bypass and now the car is as fast as I expected it to be. Fast enough to whack the ass end sideways in second gear on a freeway on ramp.

I would suggest you check for fully opening throttle, throttle position switch sensing full open, correct fuel pressure, correct CO setting. Also do a compression or leakdown test to see if you are developing normal compression in all cylinders.

Steve Wong has a good description of how to check the throttle position switch. I think it's on his website 911CHIPS - Performance Chip Tuning for the Porsche 911

I don't have anything to add as far as what the problem may be but when I was looking at cars I drove about 15-20 cars and I recall the 88 I drove felt sluggish compared to most of the earlier cars. I just thought it was weight, G50, refinement, etc... that the earlier cars lacked. I didn't like it as much as the SC's I'd driven. Just sayin.....

I understand your frustration, I have a 87 3.2 that was rebuilt approx. 20,000 miles ago by the PO. His shop bill shows everything was complete including euro pitons and cylinders. Since then I added a SW chip, Bursch exhust, removed the cat, new wires, cap, plugs, rotor,filters and an msd intake. Bottom line, my wifes 02 Boxster still blows it away. Any idea,!

Cam timing off?

Both of you two have something amiss. My '84 with a euro cat bypass and SW chip, and with a little weight removed (it weighs 2550 pounds) is very quick. It's noticeably quicker than my wife's 2.7 liter Cayman, and even gives my 996 a decent run for it's money.

Something's definitely not right if you have a SW chip and a cat bypass and the car still feels slow.

Perhaps something more scientific then how fast a car feels should be our baseline. 0-60, 40-60 in third or fourth. A dyno run?

I can post how many seconds it takes for my car to go from a rolling start (level ground) 2nd gear @ 10 mph to 60 mph. Then a couple of runs rolling @ 40 mph to 90 mph in 3rd gear. Thats a 50 mph spread from 2nd gear as well as 3rd. What do you guys think it should be in seconds to pick up the 50 mph? Off the top of my head I think 5 seconds would mean things are in order.
???

Blacklotus99:

Scott (450knotOffice) is a pretty good barometer for the relative performance of a Carrera 3.2.

I also own an 87 Carrera 3.2 Targa. It weighs 2,460 lbs after a liberal amount of weight reduction (pretty much bare bones). With 180,000 miles on the clock it still flat out flies. The car is very quick as per my butt dyno and relative to other modern cars. I have had the chance to gauge the Carrera's performance in several "safe and sane" encounters over the past 6 years. My car shows every bit as much acceleration as an STi, GTi, Mustang V8, Boxster, S2000, etc... Moreover, it is a hell of a lot more raw, challenging, and rewarding to drive than any of the cars I have mentioned IMHO.

So, something seems to definitely be amiss with your Carrera Cab.

Mike

http://forums.pelicanparts.com/uploa...1259428426.jpg

The chart shows 1/4 mi. in 15 sec. speed 90/94mph

first gear pulls you to 40
second gear pulls 30 mph more to 70
third gear 25 mph more 95.

Good info. Looks like you should be able to do 0-60 in about 6 seconds, shifting out of first at 40 mph.

Now, what do you guys with 'slow' cars actually see when you do this test?

I really need to figure this out, Steve Wong spent an hour on the phone with me making sure his chip was properly calibrated and he came up with several checks which I performed and all checked out right but something is dead wrong. Its been in the 50,s here in florida and thats when I used to feel the extra pull but now nothing!

If you go for an emissions test you can often get a lot of useful data quite cheaply. Mixture would be #1.

It has all been covered but here is my two cents worth.

Make sure the brown wire is un-plugged under the seat at the DME. It changes the setting to meet smog requirements in Japan and California.

Verify that when the throttle is floored, the throttle plate if fully opened. They typically need to be adjusted to reach there stop. Also, some times the hose clamp on the elbo will block its full engagement.

Verify the TPS contacts close at full throttle by hooking a Volt Ohm Meter to it. They are known to fail and the WOT maps are not triggered if it is falty.

I might add that you could try unplugging the O2 sensor where it goes through the motor sheet metal in the motor compartment. This will also trigger the WOT map.

I am assuming you do not have something like big aftermarket cast wheels or such.

Being a G50 cab the weight difference is probably about 150+ lbs or like driving a 915/3.2 coupe with one of your buddies aboard. The spare, jack, & tool kit can be removed for a 50lb saved. The battery is 65lbs and can be down sized for a little additional savings. Rear seat backs and belts for another 20+lbs. Thus, you can get 100lbs off pretty easily without much expense or loss of comfort.

I am a big believer in verifying ones AFR's on a dyno. Even if running a SW chip. If you do this, you should get about 215hp to the rear wheels with a chip & cat bypass. It typically only costs about $100-$150 to do this and should put all to rest.

brown wire? is there a picture of this wire? I have a 3.2 and never heard about that trick before. not saying mine is slow by any means. but every little bit counts!

Results are in:

Three pulls form rolling @ 40mph 3rd gear to 90mph 10.1, 10.2, 10.5
I didn't do the 10mph to 60mph pulls

Add 4 sec to the 0 to 40 mph on chart, plus the 10 sec. from 40 to 90 = 14 sec. 90mph on the chart looks to be 13/14 sec..

It's a bit sluggish nailing it in 3rd from 40mph for the first 3 seconds then she starts to wind-up nice.

Taking it from 1st with a shift @ 40 (4 sec.) into second could take a sec. for the shift (add 1 sec.), but the rpms would be higher catching second up to 70mph (add 4 more sec.) shift to third ( add 1 sec.) within 3/4 seconds you should be at 90.
4+1+4+1+4 = 14

I would say that the 40 to 90 test in 3rd gear you should be able to do in 10 sec. for a good running 3.2.

I'm stock, no chip yet... how many sec. from 40 to 90 in 3rd gear dose it take for you ( Steve Wong ) chipped guys???

I really would like to know that.

TIA,

http://forums.pelicanparts.com/porsche-911-technical-forum/482295-what-california-car.html

Brown wire link:

nice tip mate! thanks a million

That's a great hint if anybody noticed. What it is telling me is that it's running rich which also happens to be one of the most effective ways to kill 3.2 performance.

My SW chipped 84 used to stall sometimes when I pushed the clutch in to down shift or just come to a stop. I verified no intake/vacuum leaks, head temp/switches/linkage/plug wires/cap/rotor all OK.

Then I adjusted the base A/F mixture as described by Steve Wong in this post (about half way down the page): http://forums.pelicanparts.com/porsche-911-technical-forum/370635-carrera-3-2-idle-fluctuation.html Thanks to Steve Wong & others for all the good info in this link.

This is what I did:

Warm up motor (took it for a drive).

Turned off motor.

Unplugged O2 sensor.

Connected volt meter.

Started Motor.

With the motor at idle and normal operating temperature: Used a digital volt meter to measure the voltage off the O2 sensor.

The idle mixture properly adjusted should swing evenly between 0.2 and 0.7 volts (as mentioned by Steve Wong).

Mine was pretty much a constant 0.9 volts (rich mixture).

Mixture adjustment is performed by adjusting the air bypass screw under the air flow meter with a 3 mm allen wrench (will need to remove the plug if it is still there).

I backed out the adjustment screw until the voltage bounced evenly above and below 0.5 volts.

Then I adjusted the base idle speed (as mentioned by Steve Wong as well).


No more stalling, more top end power, and another benefit: my car starts much easier when warm.


Hope this helps,

Can someone post a list of things for me to check, remember 87 3.2 no cat/sw chip/bursch exhaust/93 octane only and the engine was re-built approx. 20,000 miles ago. PO bill was almost $10 grand for upper and lower using euro pistons and cylinders. I do have Waynes book and a Bentley manuel. Went for a long run today along the beach, my wife said, I feel like your driving your work vehicle which is a six cylinder ford. HELP, Thanks!!

bklyn,

Get the care on a dyno or lat least a Innovate Motorsports LM-1or 2 to get a baseline. It will tell a lot about how the car is running. It helped me immensely in finding out what was going on.

I did a rebuild and the car was running really well but only dynoing at 151 hp and running as rich as 9.8:1. I have an SW custom chip and DC22 cams from camgrinder. Talked with both of them and got a list of things to check. Make sure the throttle is opening all the way, + activating the full throttle switch, the signals getting to the DME, checked AFM with battery and meter to make sure it was smooth output throughout the full range of motion + signal getting to DME.
Fuel pressure check and make sure all fuel injectors are firing and plug wires are functioning properly. I also did a compression and leak down to make sure everything was alright there.
Last but not least I put the dial gauge on the cams and checked my initial timing. 12 degrees advanced! Ok, screwed up the initial cam timing. HP output now in the 260 range. And the AFR is around 12.5 -13 range now.
It can be any of the above. Start with he throttle to see if it is opening all the way and go from there.

1) Check to see that all plugs are firing. With the engine running (be careful) pull one plug wire at a time and note if there is an RPM drop. You should hear one. If no drop, the cylinder is not making power.

2) Check your WOT switch. See this link: http://www.911chips.com/C1INSTR.pdf Go to page four of the .pdf file

Thanks Mike, I will start there. Checking the Bentley now, other checks will have to wait until next weekend.

I would go even more basic on a car that feels like a Ford 6 cylinder. Like 88 D says, do a compression check.

Man, if your wife notices something like that, it must be pretty bad....:eek:

Guys, had a few min. to check the throttle plate. Wife pushed it to the floor but it still had about a quarter of and inch the plate could open, would this cause the problem? I plan to ajust anyway, guess that would be the cable under the vehicle. Thanks

It is adjusted at the linkage that is on the transmission linkage. If you look at the top of the picture (just right of center) you can see the ball socket that needs to adjust the throttle. Also may be able to adjust behind the gas pedal.
http://forums.pelicanparts.com/uploa...1259535342.jpg

That could certainly do it.