engine run on 85 930/Ruf BTR
08-19-2010, 11:03 PM
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engine run on 85 930/Ruf BTR
Hi Guys,
So I am in the process of sorting out a new-to-me 1985 930 Turbo that was converted to a Ruf BTR by the Scottsdale dealer in 1987. I built a website for it here....
http://www.vintageandsportscar.com/C..._Turbo%29.html
The car hasn't had a lot done to it since 1987, so it is original which is good, but there is a list of things to do which i've been been plugging away at.
Driveability wise the car is very good, with a steady idle, good oil temperature and pressure, and no noticeable oil consumption. No smoke on start up, on the overrun, or any other time. I've put about 1,500miles on it since I got it 2 months ago.
It is a CIS car, and the same injection system, K Jetronic, as in the 80's Benz's that I've owned and Ferrari 328. With most of those cars, upon purchase, I just replaced all the consumables to start fresh: Plugs, wires, Injectors and O rings, Distributor Cap, Rotor, O2 sensor, fuel filter, air filter etc. I intend to do all that to the Porsche, but wanted to wait until it is off the road for the winter and get it all done at once, pulling the engine and detailing the engine bay in the process. While not the cheapest way to run a car, I have found that the cars almost always need most of this stuff when they get to 20+ years old anyway, so why not just bite the bullet.
With my Porsche I did notice a couple of things that I figured would go away with the above work, but could live with for the rest of the summer. Occasionally on start up the car would only initially fire on 5 cylinders, and it would take 5 or so seconds of running to run on all 6... I figured a plug/wire or leaky injector creating a too-rich mixture in one cylinder.
A couple of times when i tried to start it, and it turned over, caught but died instantly and gave out a puf of blue smoke... Sort of hiccuped. It never smoked any other time, and started fine immediately after. No idea?
Then yesterday, i was putting the car away after driving on a hot day, the engine temp gauge was about half way, not close to overheating, but warmer than it usually gets, and I turned the car off, and the engine ran on (dieseled) for perhaps a turn of the crank or two. Just a couple of splutters. I had filled the car with a 10% ethanol blend gas on that tank, which I don't normally do. It has never ran on before.
The question then is do you think the Ethanol blend gas and/or higher temp could cause the engine to run on?
Or, do you think that the missing during the occasional start up could be linked to the run on . Perhaps a leaky injector?
And the big question is do you think that it is possible that I could be doing any damage to the engine by continuing to drive it for the next month without replacing the plugs/injectors/wires etc... I only have a month of good weather left.
I think that I will fill the tank with the non-ethanol fuel and see if it goes away... Next pull the spark plugs and have a look...
What else might I do to make sure I don't do any damage...
Cheers, Lawrence
So I am in the process of sorting out a new-to-me 1985 930 Turbo that was converted to a Ruf BTR by the Scottsdale dealer in 1987. I built a website for it here....
http://www.vintageandsportscar.com/C..._Turbo%29.html
The car hasn't had a lot done to it since 1987, so it is original which is good, but there is a list of things to do which i've been been plugging away at.
Driveability wise the car is very good, with a steady idle, good oil temperature and pressure, and no noticeable oil consumption. No smoke on start up, on the overrun, or any other time. I've put about 1,500miles on it since I got it 2 months ago.
It is a CIS car, and the same injection system, K Jetronic, as in the 80's Benz's that I've owned and Ferrari 328. With most of those cars, upon purchase, I just replaced all the consumables to start fresh: Plugs, wires, Injectors and O rings, Distributor Cap, Rotor, O2 sensor, fuel filter, air filter etc. I intend to do all that to the Porsche, but wanted to wait until it is off the road for the winter and get it all done at once, pulling the engine and detailing the engine bay in the process. While not the cheapest way to run a car, I have found that the cars almost always need most of this stuff when they get to 20+ years old anyway, so why not just bite the bullet.
With my Porsche I did notice a couple of things that I figured would go away with the above work, but could live with for the rest of the summer. Occasionally on start up the car would only initially fire on 5 cylinders, and it would take 5 or so seconds of running to run on all 6... I figured a plug/wire or leaky injector creating a too-rich mixture in one cylinder.
A couple of times when i tried to start it, and it turned over, caught but died instantly and gave out a puf of blue smoke... Sort of hiccuped. It never smoked any other time, and started fine immediately after. No idea?
Then yesterday, i was putting the car away after driving on a hot day, the engine temp gauge was about half way, not close to overheating, but warmer than it usually gets, and I turned the car off, and the engine ran on (dieseled) for perhaps a turn of the crank or two. Just a couple of splutters. I had filled the car with a 10% ethanol blend gas on that tank, which I don't normally do. It has never ran on before.
The question then is do you think the Ethanol blend gas and/or higher temp could cause the engine to run on?
Or, do you think that the missing during the occasional start up could be linked to the run on . Perhaps a leaky injector?
And the big question is do you think that it is possible that I could be doing any damage to the engine by continuing to drive it for the next month without replacing the plugs/injectors/wires etc... I only have a month of good weather left.
I think that I will fill the tank with the non-ethanol fuel and see if it goes away... Next pull the spark plugs and have a look...
What else might I do to make sure I don't do any damage...
Cheers, Lawrence
08-20-2010, 01:00 AM
#2
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Sounds like your problem lies in the type of fuel. These cars(and the RUF btr) were never design to run on 10% ethanol or any other type of blend. Continue to run your car on the highest octane your area has to offer. Even a slight lower octane can make the car sputter. The temp spike might be something else. Were you running it on a very hot day?possibly stuck in traffic? maybe one of the experts can chime in...Just my .02
08-20-2010, 12:15 PM
#3
These cars do not like to sit for long periods of time, they need to be driven on a regular basis. Many small items dry out/leak/ooze/stick when the sit too long. Some are self curing once you drive them a bit, others...not so much.
Fuel system "O" rings dry out and do not come back to life, where as dried gas deposits usually do clean up over time.
These cars are designed to run on for a short time frame after you turn off the ignition, there is even a "timed relay" in the engine compartment just for this pupose, others on this forum can probably tell you exactly which one it is and it's exact location.
An occasional puff of blue smoke on start-up is of no concern, provided it disipates in only a second or two.
As far as the starting on 5 cylinders..hummm..dried gas varnish deposits on the injectors pintel seats??
Injectors are $100.00 a crack, so not chump change just to replace them. I'd take them out and have an injector shop properly clean them first. I did this at a total cost of $125.00, runs much, much better now!
Sounds like you are simply dealing with a "been sitting too long blues", and I concur, run the best gas you can get.
My experiance + my .02 worth...best of luck.
Mark
Fuel system "O" rings dry out and do not come back to life, where as dried gas deposits usually do clean up over time.
These cars are designed to run on for a short time frame after you turn off the ignition, there is even a "timed relay" in the engine compartment just for this pupose, others on this forum can probably tell you exactly which one it is and it's exact location.
An occasional puff of blue smoke on start-up is of no concern, provided it disipates in only a second or two.
As far as the starting on 5 cylinders..hummm..dried gas varnish deposits on the injectors pintel seats??
Injectors are $100.00 a crack, so not chump change just to replace them. I'd take them out and have an injector shop properly clean them first. I did this at a total cost of $125.00, runs much, much better now!
Sounds like you are simply dealing with a "been sitting too long blues", and I concur, run the best gas you can get.
My experiance + my .02 worth...best of luck.
Mark
08-20-2010, 01:21 PM
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Once in a blue moon my car will diesel for a second at shutdown - in fact, it did so just this morning when I got to work. Engine temp was where it should be on a relatively cool 60 degree morning and 25 miles of 70mph driving in high gear. AFR's were at 14.2 at speed, and about 14.6 at 950 rpm idle. Everything copasetic, but still a short diesel. 1/4 tank of 92 octane "may contain up to 10% ethanol" pump gas. Could just be a hot piece of glowing carbon acting as a glow plug. The cure: Boost her up next time on the drive to work and blow out the cob webs.
I wouldn't worry about driving your car, but you may want to for piece of mind have someone check the emmissions (CO%) at idle to give you a general idea if the mixture is set correctly, and maybe throw pn a timing light to check the ignition timing.
I wouldn't worry about driving your car, but you may want to for piece of mind have someone check the emmissions (CO%) at idle to give you a general idea if the mixture is set correctly, and maybe throw pn a timing light to check the ignition timing.
08-20-2010, 05:45 PM
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Hey Lawrence, I saw your car at the car show in Stanley Park this summer. Very nice car you got there.
I only use 94 octane from Husky/Mohawk at selected gas stations here. It does contains up to 10% ethanol. I have not had any problem with this grade of gasoline. It is the best gasoline shy of race gas around here. I would suggest using this gasoline only. Where do take your car for maintenance.
I only use 94 octane from Husky/Mohawk at selected gas stations here. It does contains up to 10% ethanol. I have not had any problem with this grade of gasoline. It is the best gasoline shy of race gas around here. I would suggest using this gasoline only. Where do take your car for maintenance.
08-20-2010, 06:30 PM
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With my Porsche I did notice a couple of things that I figured would go away with the above work, but could live with for the rest of the summer. Occasionally on start up the car would only initially fire on 5 cylinders, and it would take 5 or so seconds of running to run on all 6... I figured a plug/wire or leaky injector creating a too-rich mixture in one cylinder.
A couple of times when i tried to start it, and it turned over, caught but died instantly and gave out a puf of blue smoke... Sort of hiccuped. It never smoked any other time, and started fine immediately after. No idea?
On your second symptom: Pull the fuel pump fuse and both fuel pump relays up front and your yellow relay in back, and hose down the connections with electrical contact cleaner. Slightly spread the male end posts of the relays (you'll note that they're split and you can wedge a knife blade in to spread them) for a tighter fit when re-inserted to their respective sockets. And check and clean the single spade connector to the overboost sensor (should be a white wire). 9 times out of 10 your sudden death symptoms are just electrical connection gremlins.
08-20-2010, 07:35 PM
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Thanks guys your comments are much appreciated. Yes, I had it at Stanley Park, though the paint was a mess at that point.. It looks better now! Also I just got a NOS RUF steering wheel, and a mint pair of period Recaro light weight seats. Next some RUF pedals and strut brace, new windshield and engine compartment detail and then all finished (and out of money).
I've had a few of my Mercedes stumble a bit on start up, particularly if left for a while, and the fix was new injectors. This is a bit different on the BTR in that it isn't a random stumbling, but a clear misfire. Now that you mention it, perhaps it is electrical in nature, and hopefully solved by new plugs/wires/rotor/dizzy cap. Most times the car fires up cleanly from cold. Getting the injectors cleaned deserves a look. I did buy all new ceramic fuses and clean the contacts, but will look at the relays too, thanks...
The Ethanol blend, as I understand it, should allow higher boost pressures without detonation (higher octane), but may allow condensation into the CIS injection system due to its hydroscopic properties. Rob at Tunerworks uses it, but mostly on newer injection systems. I just figured that it may have a funny side effect with my car. Timing? I don't fully understand the effects on the car.
The run-on was after the car's first drive in 2 weeks while i was on vacation, so maybe it needs to get blown out on a fast run. I don't have any experience with turbo charged cars, or tuned cars for that matter, so I am trying to be very cautious. Especially anything that could be related to the engine running lean, pre-ignition, detonation etc. I've never heard any 'pinging' thankfully and the engine appears to run quite rich if anything.
I think I'm just getting used to the car.
Cheers, Lawrence.
I've had a few of my Mercedes stumble a bit on start up, particularly if left for a while, and the fix was new injectors. This is a bit different on the BTR in that it isn't a random stumbling, but a clear misfire. Now that you mention it, perhaps it is electrical in nature, and hopefully solved by new plugs/wires/rotor/dizzy cap. Most times the car fires up cleanly from cold. Getting the injectors cleaned deserves a look. I did buy all new ceramic fuses and clean the contacts, but will look at the relays too, thanks...
The Ethanol blend, as I understand it, should allow higher boost pressures without detonation (higher octane), but may allow condensation into the CIS injection system due to its hydroscopic properties. Rob at Tunerworks uses it, but mostly on newer injection systems. I just figured that it may have a funny side effect with my car. Timing? I don't fully understand the effects on the car.
The run-on was after the car's first drive in 2 weeks while i was on vacation, so maybe it needs to get blown out on a fast run. I don't have any experience with turbo charged cars, or tuned cars for that matter, so I am trying to be very cautious. Especially anything that could be related to the engine running lean, pre-ignition, detonation etc. I've never heard any 'pinging' thankfully and the engine appears to run quite rich if anything.
I think I'm just getting used to the car.
Cheers, Lawrence.
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08-20-2010, 07:39 PM
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As for maintenance I had Rob at Tunerworks sort out my wastegate, and install some sway bar links, but he is not set up for maintenace work. Other than that I'm trying to do the work myself... In Calgary, I think I would take it to Bill at Auto Leader or Alpine... Any other suggestions?
Cheers, LR
Cheers, LR
08-20-2010, 08:18 PM
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I would recommend Riegel Tuning. Imre at Riegel is a master technician and he knows 930 engine inside and out. He is a master when come to these engine. Give Riegel Tuning a try and talk to Kevin, he is a general manager there. My car is in tip top shape since they worked on it three years ago. I used to have stuttering shutdown also (not any more). Be careful you don't go down the slippery slope of modifying your car or you will be mortgaging your house. Good luck Lawrence!
08-21-2010, 09:34 PM
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Well I gave the car a good run today, got it nice and hot, and there were no more symptoms of run on. I will have to find something else to worry about... Thanks guys.
Cheers, LR
Cheers, LR
