Hello,

I am a new 911 owner. I bought a 85 carrera that needs some help. The car has no spark, and I am trying to figure out why. I just can't wait to get it on the road!!!

Any help appreciated,
Alan

 

Welcome. Can't help you with your problem without more data. Did the car run when you bought it or has it been sitting for a while, a non starter?

 

Hello,

I bought the car not running, and it had been sitting for a while. The last state inspection was 2002, so I presume it has not run for quite a while. Please Help!!!!!!

Alan

 

Frankly, unless you know a lot about cars and these cars in particular, I'd have it towed to a shop and ask them to look it over . They'll have the capability to look it over, prep it to try to start it, and the knowledge to know just what to look for.

And my overall advice, Its been sitting for three to four years, and it was probably not in prime condition where it was parked. be very careful before you run this engine and particularly before you drive it: very likely its full of "demons."

On a car that has been sitting for four years, here is what i did in the past and would do again:

I assume from what you've said you have already turned the motor over: I assume you oiled the cylinders in case the rings were dry and caked, and changed the oil and filter first, flushed and changed the radiator fluid, etc., drained the gas from the tank and replaced it with new, disocnnected the gas line and pumped the four-year old yuck out, changed the fuel filter, put in a new battery, etc., etc., etc--all the things you should do in this situation before trying, but moving past that:
1) find out why the previous owner parked it and let it sit - very likely it was because it would not run (they may lie to you, don;'t believe them if they give you a lame story--no one parks a good car because they just don't want to drive it, most park it because what is broken is too expensive to fix), maybe it had no spark then, so there is something serious, or ?
2) rebuild the entire ignition system: replace plugs, wires, etc. You'd need to do it anyway on a car this old that sat for four years, so you really aren't wasting money, and check all the wiring for the controls, etc. This should give you a spark now, if not you have a bad ignition control somewhere:: go to a Porsche specialist, but even if you have aspark don't try to run the car just yet,
3) check out the entire fuel system, make sure you have pressure, no leaks, clean injectors, good metering. Now, when you turn it over, you should have a spark and fuel and the thing might start, if not, you have real problems and need to have a pro look at it, if the motor runs, it might smoke for a while, let it, but watch everything else oil pressure, check to see that you have radiator flow, watch for fule, oil, cooling leaks. Any smoke from the exhaust should gradually abate, the engine should run well if not smoothly.
Let it sit and idle for a while until it gets up to temperature. Try reving it up a bit. If the engine seems sound now, shut it off. (If you run into any problems along this way, shut if off immediately).

Before driving, you need to make certain that the brakes are sound - again, something like 50/50 at best after sitting for four years. Check them out (if you don't know how, just take it to a shop). And make sure the clutch really works (that fact that the pedal does means ntohing, make sure you can disengage it, engage it, and shift. Check that the trans has fluid" I'd drain and refill it if it were me. Start it again, drive it around the block, never above 10 mph, then try another around the block at 15. Take it back home, shut it down, and look for leaks and make a list of what didn't work. Then back out for a longer drive (stay close to home) at speeds of 20-25. Take someone with you to take notes on anything you note is wrong (and to help you push if it stalls).

Keep doing this, but take LONGER drives as you increase your personal speed limit on this car. Drive it for about ten minutes at no more than 20-25, then longer still at 25-30, etc. If all has gone well and its behaved itself up to 35, doin't suddenly take it out on the highway and open it up. Return home every few minutes to stop and look for leaks, etc.

I'm being realistic. It will be a miracle if there are not lots of minor and perhaps a major problem or two. Hoipe you intended this to be a project car.

And somewhere soon, change the tires: these tires are at least 4 years old and probably much older and half rotted.

Good luck.

 

Thanks for all of your advice. I own a boat dealership, and my techs are all into racecars. They as well as I have been around cars for many, many years. I have owned a 944 about ten years ago, and I know how different Porsche engineered their cars.

I have replaced the plugs, wires, cap and rotor, coil, and cleaned & checked all grounds, Oil and filter changed, cylinders lubed 3 times before cranking, compression checked(even and good across all cylinders), fuel filter changed, tank drained as well as possible, etc. The fuel pump is working and adequate fuel pressure is present. I have replaced the ECU from a running '88 donor car. I replaced the DME as well. What I am having trouble with is that the coil has 12 volts coming to it through the positive, and 12 volts leaving it through the negative. While cranking the coil inputs and outputs 10.9 volts. The coil wire has no spark to fire the distributor. I know to look towards a crank or cam positioning sensor, but I am having a hard time locating it. Might these cars have a trigger on the flywheel? If so how do you get to it short of dropping the engine? What else might I look for? IS this computer compatible with my 85, ( the reason I ask is that I was told from 84-88, you can jump foward but not backwards. In other terms you can put a 88 ECU in an 85, but not an 85 in an 88)? I am going off of here-say on that one, the info is coming from a Porsche guru! I would understand if the pin mapping were different!

Other than this, I am pleased with the car. The lights, signals, wipers, seats, sunroof, radio, mirrors, bug jets for headlamps and windshield, windows, locks, hood trunk and fuel latches, guages (except tach, and of course no data to test speedo), and even the 12V accesory outlet (cig lighter) all work!!!!!!!!!!!! I am replacing the 16" fuches with 3 piece 18's, so the tires are going bye=bye anyway.

I just thought, does the tach have anything to do with the positioning sensor, because the tach does not rev up while cranking. I don't think that it does, but I thought I'd ask.

As far as taking it to a "Porsche Garage", that would take all the fun out of it. I enjoy the challenge of making em go as much as driving them. The best way to learn them is to jump in and do it! I think once this bug is worked out I can make a great daily driver out of it. I really am excited to drive the car, PLEASE POINT ME IN THE RIGHT DIRECTION! Pour it on me I can handle it, get technical!

Thanks Buddy,
Alan
Bridgeside Marine
www.bridgesidemarine.com
540-719-2628

 

Yeah, this will be a good project car. I don't think the tach even twitches until the ignition is firing, so its non-reading is a valid clue.