No Spark
 

Last year I bought a 87 944 that had been sitting for 5 years. I am in the process of getting it running. I tried to start it this afternoon. After many tries and even using some starting fluid to get it to hit, I am unsuccessful. I took out #1 plug and grounded it to the block and got no spark. My father is bringing a new coil tomorrow to see if that might be the problem. Is there anything else I should be looking for? This is way different than my 85 Carrera but I want to learn about the 944. The car looks great, I just wish I could get it to start so I will have a good base to work with.

The car was driven from VA to NC and parked. So why would it not start now?

Welcome to the Dark Side, Young Grasshopper :)

To learn about these cars, Clark's Garage is your friend: Clark's Garage Home Page

Look under the Garage Shop Manual and the No-Start Checklist and most of your questions shall be answered.

Cheers, Keith

1. Does the tach bounce 1/16th of an inch when you crank the engine?
2. Did you get a spare DME relay to try? Clarks garage has a "jumper" to make if not.
http://www.clarks-garage.com/pdf-manual/fuel-05.pdf

Why will it not start?
The usual answer is that the Motronic DME computer is fried. Someone in the last 5 years tried to start the car and with a dead battery used a friends car or battery pack and "jumped" the battery and ruined the computer.

The computer is a 944 618 121 04 and not that expensive to get used. Usually $150 +-.

GL
John

Actually, the 1987 944n/a has the same type of system that the 1985 Carrera does, so they are the same as far as Electronics!

You have a DME/ECU, DME relay, MAF unit, reference sensors..etc., etc..

Okay, so the fuse box looks different, but the 944's fusebox is well organized IMHO.

I agree with John that the ECU/DME could be fried especially if like he said, someone "jumped" the battery and ruined the computer."

However, with that said:
1) Make sure you have spark and also make sure your Speed and Reference sensor connectors are tight. These connections, near the back of the engine/firewall, on top of the engine sometimes come undone...ask me how I know this fact.

When that happens the brain will not get the proper signals to fire the injectors.

2) So, with that said, get a noid light and check to see if you are getting a signal to the injectors.

One thing I thought of, since you said the car was parked for a while, is: could the car have taken on water? The reason I ask is, water can and will drip down from the area of the windshield into the cars cabin...AND guess what? If it does this, 9 times out of 10 the water drips into the ECU/DME brain and begins to corrode the electronics and the PCB board on the inside.

This last fact will always cause you grief because it usually takes a person many hours to finally track it down. (Once again, ask me how I know?)

Good luck and keep us posted, so we can be of help to you.SmileWavy

Whoops! I just re-read your first post and you mentioned the fact that there was no spark after grounding the plug. Sorry I missed that.

I will go back out this afternoon and tinker some more. I am going to try the coil but I think you all are right in that the ECU is fried. I live close to DC auto and know Rob pretty well. I worked there part time for a while. I should be able to get one pretty quick.

put in a new coil. surprise no start. took off the fuel rail end cap and no gas came out. i think u all are right the ecu is shot. it spins like the dickens but wont fire. i really want this car to run. heard some great things about the 944 and i want to experience it!!!!

RDM911,

Not to nag, but Do you have tach bounce when you try to crank?

Have you done the "jumper"?

Not that this will eliminate the DME but it helps to diagnose and eliminate parts.

John

+ 1000 ,I was gone to mention that but lol you beat me to it.Five years is a long time for the TB/BSB to be sitting in one spot.RDM---If the timing belt break while attempting to turn the motor you migth end up with bent valves & worst case scenario damage pistons.GL:D

should I just part the car out? Other than the dash being cracked, the car is in near perfect condition. I didnt pay much for it. I could ask 1750 as is just to get my investment out of it.

I can tell you what I did when I restored a 1987 944n/a seven years ago.

The first thing I did was ensure that I had a new battery. With the new battery, I was able to test all the electrical components such as:
1) do the windows go up and down
2) do the lights work properly
3) does the tach bounce upon trying to start the car
4) do I have 12 volts reaching the engine wiring harness and is there 12 volts reaching the coil and the injectors
5) does the turn signals work
6) does the sunroof work

Now, it does seem silly but the reason for these little tests that I recommend is to ensure your fuse box is operational. For example, inside the fuse box is a flat relay called the Bridge relay which is responsible for ensuring circuits on both sides of the car work (ie. electrical window switches from driver's side to operate the passengers side window up and down.) In other words this relay "bridges" the driver's side with some of the components on the passenger side.
I also replaced all the fuses in the fuse box with new ones which was expensive I know, but worth it. Some of the relays were also replaced with new ones.

Once I eliminated those features, I moved on to the engine compartment and tried starting the car. It would not start! So there my attention focused on the basics such as: spark, compression, fuel delivery, timing and are the injectors firing when the flywheel was turning. There was no signal, and I also thought it was the ECU/DME brain. So, I purchased a new brain and placed it in my non-starting car...got no signals and no startup.

Long story short, it turned out to be the reference and speed sensors were not making a good connection at the top of the engine where they plug into the engine harness. Once that was solved, the car would fire with starting fluid but not run...which led me to the fuel pump. So, I replaced the fuel pump with a new one.

Car started and ran like a champ. So, I then replaced the timing belt and balance shaft belt along with new spark plug wires, spark plugs, new distributor rotor and cap.

I found this forum very helpful as well as the Porsche factory manuals, Haynes, and most importantly Clarks-Gargage for information with examples.

Robert is a great guy over at DC so he can help you get parts. You are very, very lucky to know him and live close by and do tell him "Hello" for me.

Hope this helps you with your decision and troubleshooting. Don't give up!SmileWavy

Don't part the car. Get it running and enjoy it. I know it can be very frustrating but you will figure it out. I would also highly advise changing the timing and balance belt before cranking the engine again. It really sucks when they brake. Ask me how I know.

I think everyone that has owned a 944 has had a no start/no spark issue before.
Here is what I would do.
Change the belts first!
Spark can be hard to see, so I would check it at night.
If no spark, I would check tach bounce. Is the tach moving while cranking the engine.
Make a DME jumper to check the relay.(I have mine in the glove box, just in case I need it later)
DME relay is also the fuel pump relay.(double duty) No spark and no fuel pressure could be cause by this relay.
Check the connections for the speed/ref. sensors, or just replace them. They probably need to be replaced anyway. Then make sure they are gapped right.(if they are replaced)
Check distributor cap and rotor/replace if needed.
Check DME, find a used one you can borrow and see if that starts the car.
If non of these things work, try cussing really loud at the car, sometimes that works.

Let us know how things are going.

I have the week of Christmas off so I will get into it in earnst once the holiday rush is over and I can concentrate on the car.

RDH911 buddy, welcome to the group, addiction, sickness (therapy sessions), SmileWavy

These cars are not that hard to work on, very different than American built but not hard. Read through Clarks Garage, buy the almost worthless Haynes manual, scourer the web, check out You Tube, read the forums (Pelicanparts.com, 944online.com, rennlist.com, the944.com), ask questions. If you don't know then it's not a stupid question. Don't worry about what someone else might think, ask about what you don't know and learn. These cars are fun!!! Handling is like being glued into a roller coaster, it's like the car is on rails or you have a groove in the road. By all means have fun with it, don't get discouraged. And yes, you will hate and curse the thing at times,,,, until you are back behind the wheel with a big smile on your face.

The fact that the car has sat up for five years means that the fuel pump may have seized and may not operate. Easy way to test it is to remove the DME relay from the fuse box and jumper the three larger terminals at the same time (terminals 87, 87b and lastly 30 in that order if possible), you should hear the pump run. If you don't hear the pump you ain't got fuel. The fuel pump is located next to the gas tank on the passenger’s side at the rear of the car. Don't leave the jumper in place and walk away, by installing the jumper you have bypassed the system’s control circuit. Remove it once you are finished testing or you will run the battery down. If you hear the pump, check for spark, if you have spark try and start it. If it fires stop!!!

Change the timing belt now, don't ask why, speaking from experience!!! Belt is $20.00; valve job is over $700.00 with you doing the work correctly. Plus you will need to buy tools to do the work. Belts are easy and straight forward, a little intimidating first time. Look on You Tube for "944 timing belt change". Several members have posted information there that has helped lots of people.

Check the rollers and guides when you do the timing belt, spin them, should be smooth and silent. With the age and time sat up you should change them but at this point if smooth and quite you can buy some time. If they spin loosely, are rough or noisy change them now. They do come apart at the wrong times (at night, in the rain, away from home, in an unknown part of town, after 2:00 AM, etc...), anytime is really the wrong time.

What everyone is mentioning about tachometer bounce is the slight movement of the tachometer needle when you crank the engine over. There are small magnetic studs attached to the flywheel at specific locations to create a small current when they pass by the speed and reference sensors, the DME computer reads these signals as crankshaft rotation and RPM. The sensors are mounted at the rear of the engine on top of the bell housing, you can see them if you look between the firewall and the engine. Once the engine is rotating above 200 RPM the DME computer will trigger the DME relay and send power to the fuel pump and complete the circuit for spark. The DME computer is located in the passenger’s foot well behind the plywood, yes plywood. Look closely at the tachometer when cranking, look to see if there is some movement, it's not much but you should see something, a steady bouncing as the engine spins over. The sensors are known to go bad from age,, sitting,, or running,, ahh crap, just for the heck of it they go bad. Primarily from the heat the sensors lose their seal and moisture shorts them out. If the cars been sitting any length of time the sensors may be bad. Porsche sensors are not cheap, but BMW sensors are half the price and work fine, I run them in mine.

Not to scare or try to discourage you but to get the car on the road safe and dependable you are looking at front engine service (FOES), tires, oil change, going through the brakes, battery, electrical grounds, coolant system, hoses and belts, etc... The purchase price is only the beginning. These are great cars, get lots of attention, handle great, stop on a dime and give you a nickel in change, there's nothing like them if you like the car. The styling is timeless. For cars that are 22 to 29 years old there are modern cars today that fall short in safety, handling, economy and reliability of these.

Don’t part it out. These cars are getting fewer by the day. Age, accidents, parting and theft make these cars that much more valuable daily. Each of my two sons drive one, a 1983 and a 1988. They love the cars. What I keep hearing is “My friends drive XXX and have payments and mine’s a better car and it’s paid for”. I have a 1987 Turbo, work in progress, garage queen, sat for five years, just like yours. After FOES (T-belt, balance belt, collars, seals and water pump), all new turbo seals and hoses, coolant hoses, sensors, brakes, rotors, fuel pump, filters, vacuum lines, flushing systems, tires and many other items that kept cropping up I am nearing the journey’s end. Now the fun begins. :)

Feels like I wrote a novel, enjoy the read and don’t get discouraged. ;)