The cat was literally glowing so I would say it was hot enough Still putting out black smoke.

I'm going to send this MAF off to Rich to see if it really is not working correctly. Better to have it fully tested than to keep guessing anyways

 

glowing cats signals too much unburned fuel entering the cats

 

Yep, that's why I shut it down after about 5 minutes and seeing it start to glow in spots. Did not want to risk a car b que... or needing a new set of cats.

 

Update time.

I found the issue to be the chip inside of the LH being 1 set of pins off causing all the others to be 1 off as well.

Put the chip back in correctly and the car runs and idles perfectly.

Now to find some other problems...

 

Blake,

Not wishing to "pick the fly sh*t out of the pepper pot" here but in your original post you stated that the unit had run OK for hundreds of miles with PEMS in the LH. Presumably something happened to negate that status- presumably some event that you forgot to mention?

For those who have not done this changing the chip set is very easy to get them indexed incorrectly but I am a little surprised that this did not twig in your usually very disciplined mindset. Heck I have trouble remembering what I had for breakfast these days.

 

They had been swapped a few times when I had the LH serviced after it died on me. It did run flawlessly for the most part after they were installed the first time. You know the fun of troubleshooting. Is it the PEMs, the ECU itself etc. etc.

And my mind too is toasted, but from stress from work. I did not enjoy working 2 full time jobs for 9 months with a 3 month span of not having a single day off.

It ate away at me and now I have trouble remembering people's names and doing basic mental math. It genuinely worries me.

But enough of the pity party, the car is fixed and now I can terrorize the country club again!

 

If you do not have food, do not have water and do not have sleep it is the latter that will do for you first! Take good care of yourself- nature rarely gives second chances- not the ones where you get off Scott Free that is!

 

Without a chip (or a PEM) plugged in properly the LH was dead, its microprocessor was not micro-processing. This is the dead-LH syndrome where it just fires the injectors whenever the key is on. The telltale symptom is a tick-tick-tick from the injectors with key on, engine stopped. This usually floods the engine causing a no-start (and can hydro-lock it given enough time), I am amazed that it ran at all. But that certainly explains the pig-rich, glowing cats, etc.

I don't know whether Porsche intended this as a limp-home mode if the LH died (similar to the fixed-pulse limp mode with the MAF dead or disconnected), but if you ever hear tick-tick-tick from the engine when you turn the key on (before starting), get the LH to the doctor.

Also be aware that Rich Andrade's rebuilt LHs may not be Sharktuner-compatible. This is an old problem that I thought was fixed, but I had one recently, a fairly recent Andrade rebuild that would not work with Sharktuner. The only option offered was to buy another with no assurance that would work with Sharktuner either. The customer got a rebuilt LH from Louie Ott instead (JDS Porsche/John Speake rebuild).
[Just a PSA, not meaning any criticism].

 

^^ The LH was just serviced by him. A few caps replaced a good looking over. The tile circuit is still original and in place. The computer was replaced at some point with a new one (built in Spain).

Funny enough there was no ticking of the injectors. It only fired when cranking and running. Still a weird issue to track down as none of the symptoms I've had I have seen on this forum before.

 

Hi Blake,
I just read your posts....glad you got things resolved. In the future, if you need a hand with something let me know. I'm in Moorpark. I've got a recalcitrant '89 as well.

Best - Coleman

 

Just for future reference for those reading along, I would not have suspected the MAF if the car ran the same with it disconnected. It should have gone into a limp home mode which is "driveable" at least under cruising conditions (tends to stall at idle but will get you home) and is not pig rich. Your description pointed to an LH problem (as you found). A one bank ignition failure does dump fuel and would cause the cats to glow, as you saw, but your 89 is equipped with the ignition monitoring system that shuts off the injectors in that event, preventing the fuel dump, implementing the so-called "4-cylinder mode". My IMS started to trip when I went over a bad bump. It took me a couple of miles the first time to recognize it as 4-cylinder mode from the loss of power. Anything earlier than 89 with failure of one side of the dual ignition would experience a fuel dump and eventual cat fire. Hopefully your cats are OK, but they might have been damaged. Your next California smog test will be interesting.

 

I should clear up the maf thing. It did run better with it disconnected as in it would idle. With it connected it would stall any chance it got. Still puked out black smoke though.

The car has had issues in the past with POs failing smog and with 215k miles on it I should replace the cat at some point.

The cat only was glowing red in around 4 spots. 1 near the air injection and a few others around in the thinner areas of the cat. None larger than 1 square inch.

I hope the car passes but I'm probably going to order a new cat for it anyways at some point. Or buy a used one under the guise of a "muffler".

 

What do you mean by "I'm going to order a new cat."?

 

BTW, there are aftermarket cats for sale that are approved in California. I bought some. BUT when I tried to have it welded in by a muffler shop, they found it was not CARB approved for 89. 90, yes, but not 89. It was an obvious error in the database as both cars use the same cat. I inquired with CARB, to no avail. I eventually found a fully manufactured aftermarket cat assembly that bolted right in place of the stock assembly. Hallelujah, I thought. I passed smog after failing with my original 250K mile cats. Two year later the new cats failed to pass. That's the problem with aftermarket ( read "cheap") cats. I subsequently was donated a used stock cat. I understand it's illegal to sell them. It might even be illegal to "donate" them. This is California. The used cats are doing well. New S4 cats MIGHT be available from Porsche, but they are $1500 IIRC. Mark Anderson located some NOS early cats and had them for sale a few years ago at a very good price, but I've not seen NOS S4 cats at a reasonable price.

 

I was going to buy a set of cats from Sonnen if I couldn't get a good used one (I know it's illegal but nobody is going to know without a paper trail).

Weirdly enough the 85-86 cats looks the same and fit the same (Speedtoys is using them on his 87) but they have a different part number and cost about $1350.

I'm not even going to touch aftermarket cats. I just don't trust them to last over 2 years.

We'll see the next time I need to smog the car and find someone that can do a pretest. This car was a gross polluter in the past and I don't want to hear about it under my care.