Little impromptu survey here. If you have a Euro 928 in the US, I'm curious about the following: What year is your car, what FI system does it have (CIS or LH-Jetronic), and what was done to it when it was imported to the US.

It's quite possible that whatever closed-loop solution the importer installed was removed long ago, but if you still have it or remnants of it, I'd like to hear about it.

My recent discoveries about the air injection systems on the Euro versions lead me to believe it's basically impossible to make an effective closed loop system for these cars. Unless you monkey with the air injection.

Thanks,

Bryan

 

I have a 83 928S "euro-spec", The only changes done by the importer was to disconnect the headlight aiming control, install "Ford" Cats. (The "cats" have since been removed) and change the speedo, just the speedo, all other gauges are in German.

80-83S-3-auto
(Euro)
4.7L-16v
M28/12
300hp
263 ft/lbs
10.0:1
K-Jetronic

-Bob

 

I took an 84 Euro motor with LH injection and installed it in my 1980. The original car had a smog pump added, Ford cats, and a computer spliced into the Bosch LH brain. The computer was made by Neutronics, they are still around and can be found on the web. This computer integrates the O2 sensor with the Euro brains. Also, a Ford vacuum valve was installed between the smog pump and tube going to rear of the heads. I think the original car was imported and licensed in Arizona before coming up to California. Hope this can be of some help.

Richard.
79 A/T
80 5 spd

 

-My '85 S2 was built for Austria, but imported with 12 km on the clock. It was federalized by "Southeast Conversions" of Miami on June 25, 1985. I understand that they had to change the doors, the glass, the speedometer, and add catalytic converters. The S2 was produced in '84-86, and had an air pump but no oxygen sensor. Not needed when there is no cat.

Lamba systems, which use the oxygen sensor's information on O2 in the exhaust stream, are there to make the catalytic converter more effective. The system makes minor adjustments in fuel pressure to accomplish this.

The main difference between the S2 and the European S is in the mass air flow sensor, which used a hot wire sensor instead of a vane type sensor. This allowed it to measure air mass instead of just volume [thus automatically correcting for density altitude...], and allowed the engine to develop 10 more hp and 32 more ft/lb of torque. The engine also had 10.4/1 compression and twin distributors as well.

I've added a K&N air filter, a pair of S4 catalytic converters, and a Borla exhaust to my black/champagne 5 speed. I currently have some injector fouling issues- this car was made for Europe where the fuel has far more aromatics, and as a result my injectors frequently foul. I've not been able to completely eliminate this- it manifests itself as some hi-throttle missing on hot days. When it runs right, it is amazing how hard this car pulls, especially above 3000 rpm.

Interesting side notes are the pod warning lights in German, the metric temperatures on the climate control, and the headlight dipping system that US models never had. Also, there is the "nebelsushluchte", or rear fog light located to the left of the license plate, and the side turn signals ahead of the doors.

Normy!

 

I also have an '84 Euro-S A/T (seems this '83-85 period was popular). A short list of what it looks like was done is: cobbling of single-pipe cat onto dual-pipe system (see one of my previous posts about exhuast for a picture), addition of turn-signal flasher forward of the wheel wells, replacement of speedo, and disabling of headlight aiming (at least, it doesn't work now). What It did retain was all the German labels and warning lights, the rear fog light, the "sekurit" glass, and the fuel economy guage. I would assume that the engine is the LH-Jetronic, but cannot confirm the intended 310 horsepower because of apparent camshaft replacement (which may help or hurt the power). The import sticker says it was imported by "European Auto Sales" and mfd in april of '84, but gives a quite dodgy weight (if I'm reading it right) at 4400 lbs! Perhaps it was used to smuggle some Eastern-bloc escapees to freedom...that would explain the skeleton in the left rear wheelwell.

 

Cool guys. Good info.

The 928 was a very popular grey-market import car, as was the 911. The 924 and 944 cars not so much.

Typically, the importers would put an O2 sensor into the exhaust system (speaking from firsthand experience with a grey-market BMW 3-series here), connect the O2 sensor up to a box (my BMW had a Neutronics box too) and the box also intercepted one of the wires in the ECU harness, which undoubtedly controlled injector pulse width. Then, the air flow meter was opened up and the spring tension (L-jet flapper door air meter) increased so the car would run lean. The Neutronics box would sense this and increase the pulse width, thereby getting the car to ping-pong around stoich. This was the theory anyway. In practice, these cars would show up at a mechanic's shop within a few months with running problems. The mechanics would disable the Neutronics box, the car would go back to open loop, and run great the rest of its days. They run close enough to stoich that the cats would be fine even in open loop.

With the LH-Jet 928, I can see the grey market importers doing some head scratching. First off, they can't just set the air mass meter to run lean like the L-Jet because there's no mechanical system to mess with. So that's the first problem. The second is that the air injection would make an aftermarket O2 sensor think the car is running lean all the time, and enrich the mix to compensate. The car would then be running really really rich. So the closed loop solution for these cars must have altered the air injection (as has been described further back in the thread a tad) and a more sophisticated Neutronics box that could compensate for rich and lean.

This is probably why a lot of these responses are "they just put in a cat and that was it" because most importers were very lazy and greedy, so the easiest thing to do was just put in a cat and not mess with the engine management. They didn't want to deal with the sophisticated electronics and the air injection, so they just filled out the government forms and stuck in a cat and called it a day.

In case you can't tell, I find this subject absolutely fascinating. Sad really.

Bryan

 

Good post Bryan, but I'll add one thing that I've learned on this board: The S2 with LH Jetronic did indeed have a mixture adjustment screw! On the driver's side of the MAF sensor is a socket with a 3 mm hex head adjustment pot. Turn it clockwise to richen the mixture, and CCW to lean it. Kind of like an RC model airplane engine, though you turn it the opposite direction! My car has an oxygen sensor, but it serves only as a plug- it is not rigged to any control box.

Normy!

 

I don't think the adjuster on the LH air mass meter affects anything but idle though, does it? I could be wrong, but if it follows the same model as other Bosch FI systems, this is an adjustment for idle mix only.

But since all my troubleshooting has all been for nought because of my ignorance of the air injection system, it's possible that the adjuster on the air mass meter does shift the fuel curve througout the rev range.

I suspect it's idle mixture only though, so an importer still couldn't lean the mix across the board and implement the standard "Neutronics" box.

My car was the same - it had a US exhaust on it when I got it, with a dead O2 sensor filling the hole in the cat, and the car air pipes cut off and welded shut. Which is fine with me. The less the importers do to the cars the happier I am. Less work for me to do to put it back to how it should be.

Bryan

 

I've got an 182 Euro S (engine code M28.11). I've got the original owners bill of sale where he bought it new at a Porsche dealership in Germany and registered it in Texas in July of `82. It dosen't appear to have been 'americanized'. It does not have the marker lights in front of the front wheels or behind the rear wheels. All verbiage is in German and spedo is in KPH. It has K-jetronic (CIS)injection. The only mod to the engine I can see is that someone may have either removed the original air pump (PET shows one as standard equipment) and replaced it with an idler pulley or added the air injection diverter and air tube that runs along the passenger side cylinder head but did not connect it to anything. It also has the twin pipe exhaust setup with no 'catastrophic perverter' or O2 sensor (open loop).

 

OH Paul...I'd KILL for a metric speedometer face! Mine has been changed to a 170 mph face with no km/h markings whatsoever. I've lived in Europe, and actually learned metric in school before they taught me english measures [I still don't fully understand english measurements!], so it wouldn't faze me to drive around at km/h.

Anyone know where to get one?

-As to the mixture screw on the side of the MAF sensor, I think that it adjusts the voltage signal to the computer, and as such it works across the rpm range. However, since voltage changes radically with increased air flow [as at increased throttle] while the voltage change due to changed screw position remains the same, the relative change thus becomes smaller as the engine revs out and this screw thus has less effect. Also, the screw pot takes 30 turns to go from max rich to max lean, and vice versa, so it has a minor, but definite effect.

Normy!

 

That's cool. You do occasionally see a Euro version that got here with no changes whatsoever. I associate this with cars that were originally registered in places other than California, typically in the midwest and south. Some importers got into trouble in the mid 80's for just filling out the paperwork and not modifying the cars at all. From their perspective, it's a great idea because they make more money, the cars look and perform better, and what are the odds that the big, slow-to-react government is going to catch wise? Well, they did.

Anyhow, Paul it sounds like your car is one of the lucky ones that didn't get altered.

Something else I've learned. The '84-'86 Euro has a 2.73:1 final drive. The US version had a 2.20:1. So if the importer swaps in a US speedometer, it's calibrated for the 2.20:1 final drive. Not the 2.73:1. Therefore, your speedometer will read quite optimistically. Possibly one of the things that makes the Euro version seem so much faster. But on the bright side, the odometer is driven off the same signal, so if your car got a US speedometer on day one, I think your can multiply the mileage shown by about .81 to get your true mileage. Am I right on this?

Bryan

 

Well you asked Bryan;

Wrong on the speedo thing - the speedo trigger
wheel is driven at wheel RPM so will be right
regardless of ratio.
Incorrect tire diameter will throw it off.

My '83 Euro has a 2.75 rear gear by gear tooth
count not sure where the diffrent numbers come from {2.75 v. 2.73}

 

Bryan-

I've checked my '85 S2's speedo by driving next to a friend at a certain MPH and asking him later if I was doing that speed. I'm confident that the speedo is accurate. All they do is change the little plate on the speedo with the silkscreened numbers.

As to final drive on S2's- I believe it is 2.73. I turn 2200 rpm at 60 mph in 5th gear.

Normy!

 

The risk I see with a non-Americanized car is that someday NYS (or whatever state you live in) may not let me drive it on the street if they start sniffing my tailpipe. Oh well, It'll be a track car then. The only other (minor) problem I've had is that car insurance companies do not recognize the VIN as being valid. Once or twice a year I'm explaining the difference between US and Euro VIN's but they just smile and nod and never really understand.

 

Paul-

I've gone around and around with people on this board about this subject, but from what I've been told, 928's run so clean that a decently tuned car will pass emmisions inspection. Even without a catalytic converter!

[I still say the cat should be left intact....]

As to registration- this indeed can be a problem at times. I'm with Allstate and they didn't bat an eye, but the Florida Department of Motor Vehicles' computer didn't want to deal with my VIN number, because of the "ZZZ"'s signifying "Rest of World" model. The lady at the DMV office had to call Tallahassee and enter the info manually to process my registration when I bought the car! I'm certain it can be done in each state, but you might have to have them do what I did. I'd bet every state has a car like this, it most likely has been done before.

Normy!