gbailey911

I appreciate all of the advice so far from all of you. Unfortunately it is raining today and the weatherman is calling for a winter storm beginning tomorrow so I probably won't have a chance to check out the car until next week ( I will be out of town this weekend).

The first thing I am going to do is check for any possible intake leaks, check the intake manifold bolts for proper torque, check the temp sensor, check the air flow meter settings, check the WOT switch, check for a mis-adjusted air screw in the throttle body( not sure how to do this, hopefully the Bentley manual can explain), check for a non-closing idle switch, and somehow check the idle valve. I have checked some of these items before but it is easy enough to check some of them again.

The last thing I will check if nothing shows up above will be the idle mixture adjustment against output from the oxygen sensor. The idle mixture adjuster has a one way cap on it. Steve Wong recommended drilling two holes in the cap to remove it. Does this cap have to be replaced after it is removed or can it just be screwed back in with the two access holes open to the atmosphere? Obviously I will have to remove the air flow meter to drill two holes in the plug. Has anyone tried using a dremel cut-off wheel to cut a slot in the cap so that it can be removed with a flat screwdriver? This would allow me to remove the cap without removing the air flow meter.

Thanks again!

Lorenfb

"Does this cap have to be replaced after it is removed or can it just be screwed back in with the two access holes open to the atmosphere? Obviously I will have to remove the air flow meter to drill two holes in the plug. Has anyone tried using a dremel cut-off wheel to cut a slot in the cap so that it can be removed with a flat screwdriver?" - gbailey911 -

To remove the plug in the AFM, just drill a small hole and use a sheet metal screw,
once inserted, to pull the plug off. It doesn't need to be replaced. Again, don't adjust
the AFM or make other adjustments until you're sure the mixture needs adjusting.

As a simple check of the mixture, you can disconnect the O2 sensor and use it
as a test device with a voltmeter to check the mixture. A voltage greater than
.60 volts indicates a rich mixture & a voltage less than .40 volts indicates a lean
mixture.

At least do some sort of testing before you assume that the AFM needs an adjustment.

Peter Zimmermann

George: The simplest check to start with is to establish your baseline by checking/setting the CO%. This has nothing to do with smog, but it will tell you where to start if you really do have an unusual idle. Contributors to this thread make very valid points, but the car still requires that the CO% and idle speed are set every 15K miles, following a valve adjustment and installation of new spark plugs. The correct spec for the '87 Carrera is 0.6 - 1.0%, measured before the cat with the oxygen sensor disconnected. You should have less than 300 ppm HC. When the measurement is done you will probably discover that your mixture will not fall below 2.0% CO, even 2.5%, which can cause your lumpy idle. If that's the case the air flow meter will have to be replaced in order to set the CO% to the correct spec, this is not a rare problem. Of course, as others have mentioned, there are a host of other problems possible, I've seen intake manifold gaskets be the culprit more often than not. I'll close by saying that I've driven a few '87s, with every spec on the money, and they still idle kind of lumpy. The problem is much less common than, say, '84s, but it can happen. Even 993s don't have perfect idle speed. But setting the CO% is all-important - I believe until that's done you really don't know what the car is doing or why.
Pete

Ellsworth Wente

I "solved" my idle problems in my 87 last summer by throwing money and parts at it. figure it had 125k, so might as well. I had K&N oil goo in my AFM from a K&N filter. So I removed the AFM and disassembled it to find some dead spots on the potentiometer trace (with an ohmmeter) I slightly bent the wiper arm so it would make a new track, cleaned it with alcohol, and cleaned the k&n gunk out with throttle body cleaner. That improved things... then I took the idle control valve out and found that it was all gobbered up... so I cleaned that with carb cleaner. still a bit rough... so I replaced the cylinder head temp sensor with a two wire unit since I had the old single wire version. And while I was in there, replaced the O2 sensor since it was of unknown age. after all that, she purrs at idle. never bothered with the co test... figured cleaning out the idle mix channel in the afm removed all the gunk and brought it back into range.

DonMo

Do you feel the love, I feel the love.

rbcsaver

George,
The question that I was about to post to you, before noting Ellsworth's post, is do you have a K&N or similar air filter? If so, you may have your MAF and other components. I have written on this topic before and you can find them in the archives. I had the same problems as you and spent ALOT of money and time chasing the problem until I realized that errant purple oil may be the problem and it was. Do not use choke cleaner though. Spray Intake cleaner into the intake, with the motor running, after removing your filter to see if it solves the problem. See:
https://rennlist.com/forums/showthre...eferrerid=7923

Also, I have a SteveW chip and couldn't be happier with it. Ignore Loren's comments about the chip being your problem.
regards,
Steve

Lorenfb

"If so, you may have your MAF and other components." - rbcsaver -

This engine & ALL 3.2s don't have a MAF, they use a AFM. AFMs are NOT affected
by K&N problems as are MAFs. Actually, AFMs "like" a little oil so they move smoothly,
which is recommended every so often.

"Ignore Loren's comments about the chip being your problem." - rbcsaver -

You have to love the "absolutes" provided by some!

So, if you're SO confident about your "absolute", please explain to
us all why a performance chip COULDN'T possibly cause a rich
mixture which would result in a rough idle.

Please be objective with your response, & don't be like some & just tell
us that you "feel" that a chip just couldn't possibly be a problem source.

Steve W

And what would there be to gain by any chip tuner in changing the idle map fuel mixtures?? This is the most ridiculous thing I've ever heard, and proves what little you know about EFI tuning. I think the burden of proof is on you to explain why a chip would cause a rich idle mixture.

Lorenfb

"And what would there be to gain by any chip tuner in changing the idle map fuel mixtures??" - Steve W -

Like I said, you never really know what you get from SOME performance chips.

By-the-way, the thread starter has assumed his rough idle problem
to be caused by a rich mixture. That's an assumption, as the CO
has not been measured!

Some on the Pelican Forum have reported idle instability problems from some
performance chips after the installation and requested a modified chip to correct
the problem. They definitely noticed the "before-and-after" problems.

"This is the most ridiculous thing I've ever heard, and proves what little you know about EFI tuning." - Steve W -

We really don't need "slams" on this forum as you find on other forums.

Marc @ Red Line Service

All you guys have to stop spitting on each other.

First the running problem.
1. Check and re-torque your intake manifold(8mm cheesehead nuts) common lean mixture problem. Also inspect the washer under the nut, early 3.2's had a standard 8mm washer later cars had an updated thick washer, aprox.3-4mm thick. this prevented loosening.
2. Inspect the vacume line to the front of the engine drivers side behind the fresh air fan. Look for cracking where the copper/gold colored metal line joins the rubber line(crimp fitting).
if it's cracking replace it.
3.Check the basics. Air boot tight at air flow meter? Tight at the throttle body?All vacume lines in good shape and properly attached?
4. Now check fuel mixture. Pre-cat,O2 sensor disconnected. If your c.o. is 2.5% and you can't adjust it replace the air flow meter,not uncommen on an 18 yr. old car.DONT FORGET,proper adjustment requires setting fuel mixture, then bypassing the idle stabilizer at the engine bay fuse panel (refer to factory manual)set idle then go back and recheck c.o. Remmember each c.o. adjustment changes idle, and each idle adjustment changes c.o.You may have to go back and forth several times.Good luck with your running problem.Remember O2 sensors go bad eventually also, so if everything specs o.k.and you unplug the O2 sensor and it smoothes out plug it in and it all goes to heck it may just be the sensor. We've seen a bad sonsor or damaged sensor wiring make a car go full rich.
NOW FOR THE SPITTNG
Steve I'm sure you make a fine product,Dave I'm interest to know what Loren ever did to you except possibly question something you posted.
RED LINE SEVICEis a true believer that for all around performance, smooth idle,long term reliability,and enjoyment NOBODY makes a better chip than Bosch/Porsche. Think about it millions and millions avbailable, the finest engineers,and all the test facilities known to man. How can anyone improve on that for all around performance? Yes a chip can give more power,higher red line etc. But all around stay stock or don't worry about some minor deficiencies for improved power.
p.s. make sure your chip is street leagal and aproved for use in your state.
LAST LOREN
I beleive those of you who bad mouth Loren don't know him and shouldn't get the space to express your opinion on any web-sight, everyone is entitled to there opinion and bad mouthing Loren is just embarrising yourself. Those of you who know who we are respect our opinion, and we respect Loren's opinion. He is almost always right on the money,spends the time to answer many of your questions(free of charge)and has a true love and understanding of Porsche's. How can you not respect his opinion. And in southern Cal. a hotbed of Porsche's who do the independants AND the authorized dealers call on for technical expertise and E.C.U. rebuilds? LOREN. Enough said.Let your reputation speak for you.
Marc Bixen, Owner/President
Redl Line Service
Santa Monica Cal.

creaturecat

Mark @ Red Lline Service re: Loren - Well said - Loren is a wealth of info. -
Please no "pelican style" badgering guys!

J. Brinkley

I was deleting pic's and found this, figured I put it up. This is the "pipeline" Marc is talking about, #2 in his post. Mine went a couple months ago. You can fix it with a little chunk of hose, no point in wasting $125.
I've followed Loren's checklists before. They always have fixed my problems.

Dave Thomas

Marc, my issue is not with Loren's technical knowledge - no arguement there.

The first problem is his habit of attacking those who disagree with him, being extremely condescending with comments like "stick to polishing your car". He has an extensive history of getting nasty on Pelican, to the point of getting himself banned there. A few weeks ago, some guy disagreed with him and he stalked the guy's posts and ridiculed him on 5 separate threads. He may be smart but he has absolutely no social skills.

The other problem (which we will just have to disagree on - Steve has hundreds of very satisfied customers), is the benefit of performance chips, particularly Steve Wong's chips. Loren has been on a vendetta against Steve for a couple of years. The dispute is well documented here and on Pelican so I won't completely review it. But the basic issue is that every time Steve's name comes up, Loren jumps in with blatantly false information, trying to scare customers away from Steve.

That would be all well and good, except for the fact that apparently Loren has been hawking his own performance chip around Southern California, with little or no success, which makes him an incredible hypocrite. He's been called on this and asked to explain himself numerous times, both here and on Pelican, and he's never responded. That's usually when he disappears, only to emerge and start all over the next time Steve's name comes up.

So, Loren, for the hundredth time, care to explain?

I hope Loren can change his ways and play nice with the other boys, but I'm not holding my breath.

Lorenfb

"I guess an unintended consequence of the Pelican ban is he's going to turn up more here." - Dave Thomas -

So what's this all about, a technical/useful contribution to a thread?

As I said initially, like many of the posts found on the "other" forum, "slams".

Need I comment/respond further!

Dave Thomas

And again, no answer to the question.